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BeTrue3D – Smallbot

Starting a new series of posts about the new small printer I’ve been obsessing about lately. I’m calling it Smallbot (for now), as it’s rather small compared to all the large machines popping up all over.

I’ve never really printed very big things, nor do I normally print stuff just to print stuff, so generally my xBot (20x20x22cm or so) is larger than I really need, so decided to design a new one.

Design goals:

  • Small print area 10-15cm on all axes. Maybe larger on Z axis.
  • Small printer
    • Super rigid
    • Enclosed machine
    • Easy to move around
  • Rails on all axes
    • CoreXY
    • Hidden belts
  • Watercooled hotend
    • Custom designed or cut over Chimera+
  • AC heated bed
    • With Resettable Thermal fuse
  • Build in everything:
    • PSU
    • Controller – Duet3D something.
    • Waterpump and radiator.
    • RPI Zero or normal
      • For Raspberry Pi Camera and other functions


I’ve drawn most of it in Fusion 360 and I’m close to be able to send files to manufacturing – Meaning to have the plates cut and trying to find someone to CNC the custom watercooled heatsink for the hotend.

Wow, that’s fast and stuff.. but wait! I’ve ordered some rails and they wont get here untill some time in late november or some time december.. and I can’t really starting having plates cut to size untill I get the rails home and have a chance to do real world measuring, to make sure my design fits them.

Look and design

Everything is subject to change and there are still things needed to be done, but the following will give you an idea.

Video in and around the machine without most panels.

Most panels in place and more details and changes in place.

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Duet (2) WiFi – Getting started

Been a while since I last wrote about the wonderfull controllers from Duet3D, so, seeing as we just had Black Friday, and E3D-online had a super deal on Duet (2) WiFi (was £20 lower that day), I now have myself a brand new Duet WiFi 1.04a

  1. First off – (2)?
  2. Lots of changes!
  3. Getting started using Duet WiFi
    1. Usefull pages
    2. Links to Firmwares and Drivers
    3. Program(s) needed
  4. First Step
  5. Second Step
    1. Check current firmware version
    2. Downloading newest firmware
  6. Setup WiFi
    1. Status of WiFi
    2. Add WiFi SSID
  7. Connect to Web GUI
  8. Check factory config.g settings
    1. Machine name
    2. Delete networking settings
    3. Verify WiFi module on
  9. Update Firmware
  10. Update Web Interface
  11. RepRapFirmware Configuration Tool

1) First off, what’s the (2) i write, you might ask?

Well, the 0.6 and 0.85 are Duet (1) boards, while Duet WiFi and Ethernet are (2).
I guess the numbering started popping up, as they are working up to the release of number 3 next year. Just a guessing of mine mind you. 
Regardless though, it’s means my very first pre-ordered Duet WiFi was also a Duet 2 WiFi.

Duet3D has a dozuki page on their Version Numbering. Although it doesn’t contain a whole lot of information  at the moment, it does show current versioning are up to 1.04, meaning my new Duet Wifi, sorry, Duet 2 WiFi 1.04a is the newest iteration.. unless there is a 1.04b or c, or…

2) Lots of changes!

Up untill now my newest model has been a 1.02, and since then I can see; 3 new mini removable fuses added, new pins for jumpers and for selection of fan header voltage. Reset button has been moved and the Erase button has been replaced by jumper header, so we don’t accidentially Erase our config!

The biggest change I guess, is me though! uhh?
Yes, me, I’ve learned a lot since I wrote my first post about Duet WiFi, both about ferrules (hehe), but also about Duet WiFi, the firmware and practical usage of it, so I’ll take my new wiser fpv goggles on, and take a tour on getting started using the Duet WiFi (obvious I recently started with Quad FPV?)

3) Getting started using Duet WiFi

Lets start by compiling a list of usefull pages and needed programs:

3.1) Usefull pages

3.2) Links to Firmwares and Drivers:

3.3) Program(s) needed

  • We need YAT terminal program. In my previous old post I said Pronterface/Printrun, but that one converts letters uppercase, so it’s no use for setting up most WiFi passwords, and other things.

4) First Step:

Place you’re Duet controller on a safe surface like a silicone pad, a table or piece of paper. Just do not use the anti static bag it came in, as a conveniently platform, as they basically work in reverse that way, from when the electronics are inside.

Connect your Duet WiFi to your computer using the USB cable that came with it.
If you have allready installed the Duet Driver, the board might allready just show up in your Device Manager.
If it does not, install the drivers and you should be fine.
If you need help to get it to show up, you can find detailed instructions here, on Duet3D Dozuki.

Note: If you are using some random USB cable you might experience that nothing happens. I’ve also tried having to reboot my computer before something happened. Especially if I previously had worked in Cura or other programs that likes to hog the Com ports.

From Duet3D

5) Second Step:

Download, install and run YAT. It should automatically connect to your Duet WiFi
If it’s bugging you, you can find detailed instructions here, on Duet3D Dozuki.

5.1) Check current firmware version

Now that you have YAT connected to your Duet WiFi, you issue the command M115 (just enter M115 and hit Enter) and watch the response in the Monitor Window as shown below.

5.2) Downloading newest firmware

Now go to Github page for RepRapFirmware and check for a newer version.

Here we can see that the newest current version is 2.02RC5 (RC = Release Candidate). In order to get this we download the Duet2CombinedFirmware.bin file.
Also download the newest current version of the file. This zip archive is what makes up the Web GUI (Graphical User Interface) for our Duet.
Save them someplace you can easily find them for when we are doing the actual upgrade.

6) Setup WiFi

There are a few steps to get the Duet WiFi connected to our local WiFi.

6.1) Status of WiFi

First step is to check out the current status of the Duet’s WiFi module.
You get the current status by issuing M552 command.
Mine was listed as idle, but if yours is listed as Disabled, you just issue M552 S0 to get it into idle mode.

6.2) Add WiFi SSID

Now we use the M587 command to add our local SSID (network name) and password to the Duet WiFi’s internal storage.

You do it using this command:
M587 S”your-network-ssid” P”your-network-password”
If you are having issues, you can get detailed instructions here on the Duet3D Dozuki.

Once added, it will display an “ok” in the Monitor window. Now issue M552 S1 to enable the WiFi Module.
It will now connect to your network and list an IP after 20-30 seconds.

Note: If you disconnect the Duet WiFi before you’ve made the necessary changes to the config.g file using the Web GUI to ensure the WiFi module start up automatically at each power up, you just have to connect using YAT and enable the module again by issuing M552 S1.
If necessary, you can issue M552 to have the current IP displayed

If you can’t connect to the Web Interface even though it displays an IP in YAT, try disabling WiFi (M552 S0) and then enable it again (M552 S1).

7) Connect to Web GUI

Now that we have done all the terminal work in YAT, we can connect to the nice Web GUI of the Duet cards. You just open your browser (I’m using Chrome) and enter the IP listed in YAT. In my case it’s and we are now looking at the Web GUI of our Duet WiFi. Yours might look differently depending on window size of the browser and also versioning of the Web GUI.

DuetTest at the top is the “Machine name” and can be changed to a name of your choice in config.g

8) Check factory config.g settings

Before we do anything else, left-click on Settings -> System Editor and Config.g to open the main configuration file for our Duet WiFi

8.1) Here’s a few things we should do now:

  1. Machine name
    • By editing the line I’ve marked in blue, starting with M550, you can give the Machine for the Duet WiFi a name of your own. I’ll call it Betrue3D xBot. In order to accomplish using 2 words, I need to write it like this: M550 P”BeTrue3D xBot”
  2. Delete networking settings
    • The lines I’ve marked in a red box should either be deleted entirely, or you can insert a ; in front of each of the lines, which means they are disabled. It can be nice to do this for future reference.
  3. Verify WiFi module on
    • The black box shows the startup setting for our WiFi module. The S1 means it’s turned on automatically.

Once you’ve made your changes you hit Save Changes and you also need to power cycle the board before the Machine Name change takes effect. Notice how fast your Web Gui reconnects.. it’s just a super nice experience 🙂

9) Update Firmware

  • Click on Settings General.
    • In the area I’ve marked up with a blue box, you can see the current firmware. As we found version  2.02RC5 on the Github page for RepRapFirmware it means we can update this.
      • From the olden days we had two different firmware files. One for the Firmware Version and one for the WiFi Server Version. These two have been combined (yay) into one, so we no longer need a seperate file for the firmware of the WiFi Server.
    • In the area in the red box you can see current version of Web Interface which is 1.21.2. This is called DuetWebControl on the firmware page and is of this writing version 1.22.5 meaning we also need to update this.
  • We will start by updating to the newest firmware, which you can do by clicking Upload File(s) button and find the firmware file we downloaded previously, or you can simply drag and drop the firmwarefile onto the same button.
Find the firmware file and just double-click it.
The file now uploads super fast
Just click Yes to start the updating process.
Just wait a bit.

Once the firmware version updates to reflect the new firmware file, the updating process is complete.

10) Update Web Interface

Next up we just do the same for the Web Interface. Just double-click the .zip file and the update starts automatically.

If you’r quick, you can see how the individual files are being updated.

All done!

11) RepRapFirmware Configuration Tool

Next step is to head over to the online RepRapFirmware Configuration Tool and run through the guided setup to configure your machine.

When finishing the wizard it will generate all the necessary files for you, which you then upload to your Duet WiFi.

Note: The changes we made in the config.g will be overwritten

I’ve always used Custom Setup, as all my machine are build by myself, so I can’t really comment on the various templates, but regardless of what you do, you should look at this as a basic setup starting point, as you will need to make some manual changes in various files afterwards.

I might do a writeup on the Configuration tool at a later point, but for now, I’ll just provide the link to you 🙂

RepRapFirmware Configuration Tool

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Send files directly from Cura to print on the Duet card

Heya all.

Since last time:

As my computer had a loose connection in an internal USB connector, which apparantly touched on some 12v source, which in turn ended up frying 2 of my Duet WiFi controllers, a Duex5 and a BLTouch sensor, I went into fetus position and put 3D on pause. Especially as I had no clue as to what had happened, as the only thing I had done to my printer was updating firmware. I only figured it out a couple of weeks later, when my computer refused to start and I dismantled it… found a loose wire in my automatic watercooling system <cry>

I ended up burning not just 1, but 2 Duet WiFi cards, as I supposed it was a faulty card. Yesterday I found my Duex5 and an original BLTouch had also died!

What died on the boards?

A 5v regulator died on both.
VIN leds blew on both.
The micro usb plug fried on one, along with what I believe was an USB controller chip thing (I’m not a component expert).

I’m not sure which parts has died on my Duex5, as I only discovered that one yesterday when installing a Duet WiFi from my CoreXY, to get my xBot up and running again… luckily I had a Duex5 and BLTouch from my CoreXY as well, so now I “just” need to figure out why a few sensors doesn’t work as they should.. hopefully the daughterboard on Duex5 isn’t burned as well, but I fear this is the reason for the unresponsive sensors.

What this post is about

We are going to install the DuetRRFPlugin, which is, as the name implies, a Plugin for Duet RepRapFirmare to use in Cura.

When we have this installed we can get the slized file uploaded and automatically started (or just uploaded to) on any of your Duet printers.


If you don’t have it, or know about it, I’ll recommed you head over to Ultimakers’ Cura download page and get it. I’ve tried pretty much all mainstream slizers, and some obscure ones. I even owned S3D for a while, when tinkering with the 5way full-coler Diamond Hotend, but got my money back, as S3D wasn’t for me at all.

Sorry, but here’s a bit of a rant!

I vastly prefer Cura because of it’s unified 1-window interface, where you control everything from 1 place and don’t have to dig into all sorts of menus and open different windows, to get what you want.

I recognize how It is a subjective thing when picking favorite slizer, as we are all different, but functional wise, Cura has more build in ready to use functions than S3D and you don’t have to code anything in Cura as you do in S3D, to get basic functions running.

I find it especially distatefull when people new to 3D havn’t even tried anything else are “recommended” to buy S3D without even having tried one or some of the free Slizers out there. This is the crux of my rant.

If S3D was free, as Cura is, I could understand how some people would choose it, and recommend it, as the fragmented GUI with different windows for different things appeals more to some people than Cura’s unified GUI does.

So why do I write this thing about how I prefer Cura over S3D?

Because I see a lot of new 3D People “being hoaxed” into using S3D as it surely must be better, since it costs money, right?
No, not really.
It gained a lot of early users and attention as it had build in profiles for lots of low cost printers and support, but by putting in an effort (talking to people online or using Google) most people would be able to setup their own machines in any other free slizer.

The support is for basic stuff only, and can’t help if you face some complex issue (low quality printer), nor help setting up complex stuff like 5 way diamond. They just refer to online written posts, which you have access to in any case, and which most likely isn’t relevant for your particular machine, as they are mostly written by users.

I know several people who started out using a free slizer and ended up favoring S3D, and I’m perfectly fine with that.

I just really dislike how new users are encouraged to cash out a lot of money for something before they at least have had the opportunity to try the free slizers.

Especially since the paid version objectively simply just isn’t better.

I recognize that some people experienced markedly improved results when using S3D and that’s just awesome. Super! But please, try to guide people new to 3D to try Cura or/and some of the other free slizers before asking them to pay almost as much for a slizer as many people pay for their printer.

Ohh, did I forget to mention that Cura is FREE and created and maintained by one of (if not the) leading 3D Printer manufacturers. They also comes with a lot of profiles now, but it really mostly just works without doing much of anything.

Cura theme

Once you have Cura up and running, you might notice my Cura is dark. While it’s not important to installing the plugin, you can change it by going through:

Preferences – Configure Cura – Theme: Ultimaker Dark

Click Close and restart Cura.

Install plugin (DuetRRFPlugin)

You install plugins in Cura by clicking:

  1. Toolbox – Browse packages…
  2. Now scroll down and click: DuetRRFPlugin
  3. Once you click DuetRRFPlugin, the plugin page shows up.
    Just click Install, accept the Plugin License Agreement and restart Cura.

Configure DuetRRFPlugin

  1. When clicking Extensions menu, you will notice we have a new submenu, namely the DuetRRF.
    Open the settings by clicking DuetRRF Connections
  2. In the new window, you click Add, then input the Display Name of your printer and the IP address it has on your network.
    The Display Name is just for your reference and not important. On a standard RRF setup you just ignore the last 3 options.
  3. After clicking OK, you will be presented with your settings.
    Verify you’ve picked the right IP address and close the window by clicking X.

Using the DuetRRF Plugin

  1. You won’t notice any change untill you’ve clicked Prepare to slize a file in Cura
  2. Now you can just hit Print on xBot-Medium to send the slized file directly to the 3D Printer and startup the print
    Click the down arrow for more options, like Simulate Print, Upload without printing or to Save file to local disk.
  3. If you add more 3D Printers, you’ll have the options to pick which printer you want to use

That’s it

That’s it for now. I’m back and you got a guide to install and setup a super plugin for Cura and as a bonus you also got a free rant about freeware and paid slizers 😉

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Setup E3D Chimera/Dual Head on Duet WiFi/RepRapFirmware – and watercooling intro

Some time ago I bought the, at the time, new E3D Chimera+ Watercooled hotend and some extra stuff for it.

(sorry, misplaced photo of unpacked new Chimera+. I’ll see about digging some up!)

I’ve had a bit of issues getting it up and running as the first pump/Reservoir combo I bought from China didn’t work.

A reservoir is just a container where extra water is stored to make sure the system doesn’t run low. It also makes it easier to fill up and maintain, and catch the air/bubbles the bubbles you always have in a new watercooled setup. All of these things can be done without a reservoir, but it makes it a lot easier to get going and easier to maintain and keep a look on waterlevel.

I’ve done a lot of custom watercooling on computers, servers and rack equipment (yes, you can watercool a switch and U1 server), so went into the basement to find some spare equipment.

So, why did I buy a Chinese pump when I allready had a lot of watercooling equiptment the smart reader might ask, and the answer is simply that I figured my pumps were far too powerfull, and yes, they were still too powerfull when I looked at them again, hehe.

My tubings also didn’t match precisely, which I could have worked around and I needed to print some Nylon barbs to work as an adapter from E3Ds bowden solution to the tubes – You can now buy a Water-cooling barbed adapter kit seperately from E3D, which you couldn’t at the time of my purchase… I could do all this, but I still needed a new pump and reservoir.

I could buy a new pump/reservoir combo from China and wait one more month and hope it worked this time…

Or I could buy the Watercooling kit from E3D and get going. This would also make it possible for me to get a look at their new stuff and document it for you in the form of STEP files on GrabCad.

  1. Prelude
  2. Configure RepRapFirmware
  3. Tool Definition
    1. Tool0
    2. Tool1
    3. Tool definition section code
  4. BLTouch offset from Nozzle0
    1. Mesh Grid
    2. The combined section code is like this
  5. Calibrate BLTouch for Z-offset
    1. Find Z-Offset
  6. Define Leadscrew coordinates for Autolevel
      1. How to use it
      2. X coordinates for M671
      3. Y Coordinate for M671
      4. The combined section code is like this
  7. Setup probe coordinates in bed.g

2) Configure RepRapFirmware

Since I’m using my new xBot Chimera+ Watercooled Carriage I need to both setup a new Tool (the second nozzle) which encludes configuring nozzle distance from each other, configure BLTouch placement in regards to my Nozzle, and reset my Z-offset of my BLTouch. Finally I’ll need to redo the coordinates used to do my probing sequce to autolevel my bed.. yes, it’s a lot actually, but taking it one step at a time, and it’s usually not really that hard.

I’ll recommend writing down what you do, if you are like me and work well with having documented what you do and what to do. 
Regardless of the details of your documentation I’ll strongly recommend you do not delete or change existing setup lines, but instead comment them out using ; and create a new line of code, for your new setup.

3) Tool Definition

Lets first add a new tool using M563 for our second nozzle by editing the config.g file. This includes defining which heater and extruder we are going to be using as well as the relative position it has to the first nozzle.

You can name the Tools if you like, which will show up in your web display. I’ve named them Nozzle1 and Nozzle2 respectively.

3.1) Tool0

First tool is Tool 0 (P0), using Extruder 0 (D0) and Heater 1 (H1)
M563 S"Nozzle1" P0 D0 H1 ; Define tool 0
The Tool ofset is defined using G10 and in relation to the origin of the head. I might have used the point between the two nozzles as the origin and defined offset as -10 and +10 on the X axis respectively, but I’m going to be using Nozzle 1 as the origin. This means the offset coordinates for Tool0 are all just 0.
G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets

3.2) Tool1

The second nozzle looks like: Tool 1 (P1), using Extruder 1 (D1) and Heater 2 (H2)
M563 S"Nozzle2" P1 D1 H2 ; Define tool
The offset of the second nozzle to the first one is +20 on the X axis, so it will look like this:
G10 P1 X20 Y0 Z0 ; Set tool 1 axis offsets

Note on Fans: If you use the default recommend fan0 as print object cooling fan, you do not need to define a fan.


3.3) Tool definition section code:

; Tools
; P = Tool Nr
; D = Extruder Drive nr
; H = Heater used
M563 S"Nozzle1" P0 D0 H1 ; Define tool 0
G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
M563 S"Nozzle2" P1 D1 H2 ; Define tool 1
G10 P1 X20 Y0 Z0 ; Set tool 1 axis offsets

4) BLTouch offset from Nozzle0

Next up we need to modify the BLTouch position in relation to the Head Origin, which in our case is the first nozzle Tool0.

It is our G31 in the config.g we need to modify. Just leave the Pnnn value as is.

The BLTouch is placed 10mm to the right of the nozzle, which is X10 and 24,26mm in front of the nozzle, which translates to Y-24.26.

Important: Do not use , as normal in metric systems when denoting decimals when defining the gcode.

We are going to set Z offset to 0, and setup this again later to match our new carriage.

This means our (base) G31 looks like this:
G31 P600 X10 Y-24.26 Z0 ; BLTouch offset in relation to Tool0

4.1) Mesh Grid

My Mesh grid is spanning the area from X5,Y5 up to X205,Y165 and probing every 10mm.

Tip: When doing initial setup of the Bed I like to make the probing distance larger, at 20mm to get a rough map to use for manual adjustment.

It means my M557 looks like this:
M557 X5:205 Y5:165 S10 ; Define mesh grid

4.2) The combined section code is like this:

; ## Nozzle Distance from BED - Offset. Higher value, closer to bed.
; Set Z probe trigger value, offset in realtion to nozzle and trigger height adjustment
G31 P600 X10 Y-24.26 Z0 ; Zero offset
M557 X5:205 Y5:165 S10 ; Define mesh grid

5) Calibrate BLTouch for Z-offset

Previously we reset the Z offset using G31 to Z, so it now looks like this:
; ## Nozzle Distance from BED - Offset. Higher value, closer to bed.
; Set Z probe trigger value, offset in realtion to nozzle and trigger height adjustment
G31 P600 X10 Y-24.26 Z0 ; BLTouch offset in relation to Tool0

So, lets go find the proper Z offset:

5.1) Find Z-Offset

  1. Move your sensor to around the middle of the bed. You might even want to make a Macro for this, as it can be usefull for many different cases.
    1. Herer’s a simply macro I named Move to Centerbed, where I home X and Y first:
      G28 XY
      G1 X97 Y120 F4000 ; Move probe to middle of bed
      G28 Z

      We need to home Z before we can continue, or it fails to test properly after firmware 1.21
  2. Move Z untill your nozzle is about 10cm (4 inches) from the bed.
    1. Be ready to click the Emergency Stop in case the probe misbehaves.
    2. Now issue G30 command.
    3. Your BLTouch should now send the Pin Down and your bed should now move up (or nozzle down) untill the BLTouch is triggered.
    4. Hit the Emergency Stop if it didn’t stop or the Pin didn’t drop down.
      1. Go through your deployprobe.g if the Pin didn’t drop down.
  3. With #2 successfull you put your sensor over the middle of the bed and jog Z axis untill your nozzle is touching the bed.
    1. Note: If it refuses to move as it has reached Z-minima you can type in G92 Z5 to tell it, that you are 5mm from Z=0.
  4. Once your nozzle just touched the bed tell the machine we are at Z=0 by issuing:
    G92 Z0
  5. Move Z 10mm away from nozzle
    G1 Z10
  6. Now send G30 S-1 at which point the Pin drops down and the z-axis closes the gap until the BLTouch is triggered.
    1. Z now stops moving and reports the current position without changing anything. Note down the reported value.
  7. You might want to repeat the steps 4-6 a few times to insure consistency. I personally just did it 2 times and later did final adjust by looking at print starts.
  8. Mine reported the following:
    G30 S-1
    Stopped at height 2.4mm
  9. I should insert 2,4mm now, but I’ll detract 0,2 as a safety margin, so I’ll change the Z parameters in the G31 line from 0 to 2.2.
    G31 P600 X10 Y-24.26 Z2.2
    Important: The higher Z value the closer you move the nozzle and bed to each other! It’s better to have a value too low here than too high to avoid the nozzle and bed doing a mating game when homing.
    Important: If you later redo the offset method you should reset the offset to Z0 before starting or it might lead to strange results I’ve found on some occasions.

6) Define Leadscrew coordinates for Autolevel

Since the xBot is using 3x independent motors for our Z axis we need to define the coordinates of the leadscres in relation to the hotend and carriage combination we are using.

This can be a bit harry, but lets start by looking at the xBot Probe Point Helper Drawing I made for this purpose:

The Drawing is not made specifically for the my current xBot Carriage Chimera+ Watercooled but instead lising the dimensions in relation to the rear center manual finger screw. I did it this way to make it easier for people to use their own favorite carriage and hotend solution.

If you want indepth explanation on what I’m doing here, you should read the section on Z-Leadscrew Placement.

6.1) How to use it:

Before starting you should check if your X and Y -maxima coordinates should be changed. I needed to change mine.

Now home your X and Y axes, then move your carriage to the center rear, so BLTouch is lined up to the rear fingerscrew.
The position reads as X97 and I measure the BLTouch to be placed 20mm in front of fingerscrew, meaning my nozzles are actually placed exactly at my Y-Maxima, which is Y215.

6.2) X coordinates for M671

First leadscrew

Front right is placed 153,6mm to the right of the center rear fingerscrew.

Since my center is X97 it amounts to: 97+153,6 = 250,6 for first X coordinate.

Second leadscrew

Front left is placed 153,6mm to the left of center.

So 97-153,6 = -56,6 for second X coordinate.

Third leadscrew

Rear center is placed at the center, so we use 97 for our third X coordinate.

This adds up to the first part of the M671 line, which looks like this so far:
M671 X250.6:-56.6:97

6.3) Y Coordinate for M671

First Leadscrew

Front right is placed 241,1mm in front of the rear center leadscrew, which has the coordinate Y215 since my Nozzles are exactly on top of it and it corresponds to my Y-Maxima

So we take the Y position 215 and detract 241,1, which gives us 215-241,1 = -26,1 for our first Y coordinate

Second Leadscrew

This is placed at the same point on the Y axis as the first leadscrw, so -26,1 for our second Y coordinate

Third Leadscrew

This on is placed 63,5mm further out the Y axis, so:

215 + 63,5 = 278,5 for our third Y coordinate

When adding the Y coordinates to our M671 codeline we get the following:
M671 X250.6:-56.6:97 Y-26.1:-26.1:278.5 S3

The trailing S3 defines maximum correction the leadscrews can do. Default is 1.

6.4) The combined section code is like this:

; Define the X and Y coordinates of the leadscrews.
; Must come after M584, M667 and M669
; S = Maximum correction
; Motor order: Front right, front left, rear center.
; Snn Maximum correction to apply to each leadscrew in mm (optional, default 1.0)
M671 X250.6:-56.6:97 Y-26.1:-26.1:278.5 S3

7) Setup probe coordinates in bed.g for G32

Now its sime to review our bed.g file to see if it’s still valid.

It’s not really crucial where you probe, but you should try to make the probe points as close to each leadscrews as possible.

I set all mine to 2mm from min and max for each axis.. just in case a wire or something got between my carriage and the printer edges.

The Third point needs to take into account how BLTouch is placed 20mm in front of the nozzles, as it wouldn’t be able to probe at Y215 but at best at Y190. I’ve deducted the extra 2mm and landed on Y188.

It might be a bit fiddly to figure it out, as the actual probing coordinates is for the nozzle, so can be confusing when looking at it.

; bed.g
; Called using G32
; Called to perform Autolevel using 3-point probe
M561 ; clear any bed transform
; Made allowances for BLTouch being up to 30mm in front of nozzle. Typical is 27mm+/-
Probe 3-point
M401 ; Deploy probe - deployprobe.g
G30 P0 X207 Y2 Z-9999 ; Front Right
G30 P1 X2 Y2 Z-9999 ; Front Left
G30 P2 X97 Y188 Z-9999 S3 ; Center Rear
M402 ; Retract Probe - retractprobe.g

Posted on 19 Comments

BLTouch on Duet WiFi – Configuration and usage

In a previous post we connected our BLTouch sensor physically to the Duet hardware and made some basic configurations as well.

In this post I’ll talk about Probes and Sensors interchangeably and will be using the BLTouch name/model during this post, as that is the one I’m using to test this.

If you want to read a bit of an intro into the differences between autolevel and autocompensation, I wrote a brief section about this in Is this autolevel?

I’ve had some correspondence with a lot of peopleduring the writing of this post and I’ve come to understand that I need to specify the printertype I’m talking about here. My printers, which I’m using as basis for this post are:

  1. A box type printer with fixed XY gantries at the top, working together using the cross method to move a carriage around (like an Ultimaker and my xBot), and using a single z-motor to lift the z-gantry containing the printing bed surface.
  2. My xBot which uses the same XY cross-method, but has 3 seperate Z motors for the Z axis, making it possible to adjust it automatically for true autolevel.

You can still use all information even if you are using a Tower printer (like Prusa etc), but I am going to be referring to the two machine models above throughout this post.

i know very little about Delta machines, so I haven’t written with those machines in mind. Donate a Delta and I’ll write some how-tos on it ?

In this blog-post I’ll try to go through different types of more complete configurations and usage scenarios like:

  • Setup BLTouch in Config.g including defining Mesh Grid to probe using M557.
  • Doing a Mesh Grid Probing sequence using G29
  • Doing a Basic Single Probe using G30 before print start.
  • Doing an Advanced Probing sequence using G32 for Autolevel
  • Setup Slizer Startup Gcode to apply our Mesh Grid to the z-plane after doing the Autolevel Probing.
  1. Using a Probe – Intro and Explained
    1. Auto Bed Compensation drop-down menu walkthrough
    2. Summing up
    3. Usage
  2. Wiring of BLTouch
    1. Probe switch function
    2. PWM Channel for Servo Function
    3. Duex owners
  3. Configuring BLTouch
    1. Create a deployprobe.g and retractprobe.g file
    2. Create a BLTouch Macro Group
  4. Change config.g file
    1. Disable Heater to free up PWM pin
    2. Change Endstop Settings
    3. Define Probe Type
    4. Probe Position
    5. Define Mesh Grid
  5. Total Configuration – Summing up
      1. Config.g changes
      2. New Configuration files
      3. Macros
  6. Calibrate our sensor
    1. Find Z-Offset
    2. Run Mesh Grid Compensation sequence
    3. Save Custom named height maps
  7. Before Printing
    1. Homez.g
    2. Homeall.g
    3. Slizer startup gcode
  8. Multi Z-motor setup using bed.g
    1. Z-leadscrew placements
    2. Define XY Coordinates in config.g
    3. Lets have a look at Homing using a Probe
      1. Slizer Startup and Endcode Examples
      2. Single Z-Motor Machine
      3. Triple Z-Motor Machine
  9. Gcodes used

Using a Probe – Intro and Explained

When adding a Z-probe to your 3D Printer it also means introducing a lot of new terms and it requires a fair bit of setup to do and gcodes to learn to use.

Most printers just have some sort of basic limit switch or maybe a hall or IR -sensor for X, Y and Z. This means a G28 command is enough to home all axes.

When using RepRapFirmware a basic homing sequence requires 4 files to work:

  1. homex.gG28 X
  2. homey.gG28 Y
    1. By issuing: G28 XY you can opt to home X and Y at the same time without Z.
  3. homez.gG28 Z
    1. This command will just home Z without the X and Y axes.
  4. The homeall.g file, which is executed using G28 without specifying any axes afterwards.
    1. This file normally homes all axes your machine might have.

Important: When using a Probe located on Z-min (at your nozzle) and using the most basic/normal probetype with 1x Z-motor using Mesh Grid Compensation the Z-Max endstop will be disabled regardless of any virtual axes you might make to get around this issue! 

I am told that his is not the case when using a Delta type Printer. I am not familiar with Delta configurations.

If you have 2 or more individual Z-motors and have configured Auto Bed Compensation in combination with Mesh Grid Compensation a Z-max endstop is mandatory (is it really?) in order for the Printer to calculate your Z plane accurately.

In order to use a Probe we need to configure it using several new M/Gcodes, which we go through below.

We also get a new arsenal of Gcodes to use during startup, and we can use the various functions in the Auto Bed Compensation drop down menu in our web gui:

Auto Bed Compensation drop-down menu walhthrough

  • The actual button Auto Bed Compensation constitutes a G32 which can only be used if you have 2 or more independent Z-motors.
    • When issuing a G32 command, the bed.g macro file is executed.
    • I don’t know how to make the “Show Probed Points” active?
  • The Disable Bed Compensation is used if you have  Auto Bed Compensation in effect but want to disable it.
    • This can also be done by issuing the M561 command which cancels any bed-plane changes you might have in effect by probing (or anything else).
    • The M561 is also placed first in the bed.g file before doing a new Auto Bed Compensation run.
  • G29 – Run Mesh Grid Compensation – Performs a Mesh Probe which is saved to a heightmap.csv file.
    • By probing the bed you automatically enable it as well.
    • You can use custom names. More on this later.
  • The Show Mesh Grid Heightmap displays the grid performed by G29 graphically.
  • The Load Heightmap from SD Card constitutes a G29 S1 command, which you would typically place in your startupgcode file in your slizer after the probing sequence.
  • Disabled Mesh Grid Compensation equals G29 S2 and stops the printer from using the heightmap.

Before we can run G29 we need to define the mesh to probe, which is done via M557 in our config.g file, which we will further down in this post under Define Mesh Grid.

Summing up

  • We setup and configure our Probe/Sensor in config.g
  • Bed.g is only used if we have 2 or more  independent Z-motors. Tower printers would use this method if the Z motors are using seperate drivers.
  • The bed.g file is used to define probe points using M671 in relation to our Z-motors.
  • The bed.g file is not used if we do not have more than 1 independent Z-motor.
  • You can even have multiple differently named heightmaps to use, if you for instance have different plates for different materials.


  • M561 should always be used before running a new probe sequence of any kind.
  • We use G30 (without parameters) to do to the Z-min probe as defined by G31 in the config.g file
  • If we have 2 or more independent Z-motors we use G32 to do the probing sequence as defined in the bed.g file.
  • Any Heightmaps you want to use is loaded after you have finished your probing sequence.

Wiring of BLTouch

We can seperate the 5 wires of the BLTouch into 2 seperate groups:

  1. Probe switch function:
    The Black (GND) and White (Signal – Z Probe IN) which connects to the Probe Connector on the Duet Controller.

    Note: My “white” wire is red on this photo.
  2. PWM channel for Servo Function.
    The Brown (GND), Red (+5v) and Yellow(PWM) goes either onto  a PWM/Servo connector on a Duex board or we use 3 pins in the 40-pin expansion-connector.
    Note: Regardless of wheter we use a Duex or not, I am going to be using Heater7 in my setup examples, which is PWM channel 5. I do this as it is the last one, so it’s easy to remember and it is physically the PWM channel on Duex which sits closest to the edge of the board.
  3. Here is he complete overview of pins used if you do no have a Duex board.

    1. For Duex owners, the Heater7/PWM5 is the connector you see on the middle left side here and the upper one is the Probe connector on the Duet Controller.

      Note: On the photo I have a resistor installed in the Probe Connector. This is necessary if you are using one of the older BLTouch models without the trace you can cut on the rear of it, to make it run 3.3v logic.
      Note: I had a machine where I thought I had cut the trace, but it wasn’t cut all the way, but it still worked, so you might be able to skip this. Ie mine worked fine even though it was still setup as running 5v logic, which means it was still without correct readings it seemed.

Configuring BLTouch

Now that we have everything hooked up, we need to setup our firmware to be able to use it. This includes creating some files and editing config.g and in some cases also bed.g

Create a Deploy and Retract file

Regardless of setup we need to create a deployprobe.g  and a retractprobe.g file.

  • Deployprobe.g
    M280 P7 S10 I1
  • Retractprobe.g
    M280 P7 S90 I1
    These files are used to execute our probe as needed.

Note: If you use Duex2/5 you do not need the i1 parameter

Create a Levelplate Macro Group

This is not strictly necessary, but really usefull, so go to your Macro area and create a new Directory named BLTouch.

Now we create some macros as shown:

  • Alarm Release + Pin UP
    M280 P7 S160 ; Alarm Release and Push-Pin UP
  • Pin Down
    M280 P7 S10 ; Send PWM channel 7 the s10 (angle) command
  • Pin Up
    M280 P7 S90 ; Send PWM channel 7 the S90 (angle) command
  • Self-Test
    M280 P7 S120 ; Send PWM channel 7 the S10 (angle) command

You might want to create some more macros to quickly run your probe to the center of your bed and each corner etc.

Change config.g file

We need to make some changes in our config.g file in order to make use of our probe.

Please note that some or all of these entries exists in your config.g file alrleady if you used the RepRapFirmware online configurator to create your files.

Disable Heater 7

We use M307 to disable Heater 7 to free up the PWM5 channel for our servo (probe).

I’ve put this down with my oher Heater settings for hotend (M301) and heated bed (M307) in the config.g file.
; BLTouch - Heaters
M307 H7 A-1 C-1 D-1 ; Disable the 7th Heater to free up PWM channel 5 on the Duex board.

Change Endstop Settings

Next up we need to change our Endstop Settings, which is done using M574 gcode

It might look something like this now:
M574 X1 Y2 Z2 S1 ; X home to min. Y and Z home to max. Normally Closed limit switches.
We need to remove the Z2 from this line, and add a new line defining Z as using a probe.

The two new lines are going to look like this:
M574 X1 Y2 S1 ; X home to min. Y home to max. Normally Closed limit switches.
M574 Z1 S2 ; Define Z to use Probe. Home to Min

Define Probe Type

Next up we define our probe type using M558, which is Type 5 in our case:

  • P is probe type
  • H is diveheight, which means how far bed moves down/hotend up, between each probes
  • F is the speed of bed up/down movement. If it’s too slow the Probe pin might hit the bed and cause an error.
  • T is the movement speed between probepoints.
  • The X, Y and Z denotes which axes are used by the probe. X and Y are not used, while Z is.

M558 P5 H5 F500 T4000 X0 Y0 Z1 ; Set Z probe type/mode 5. H=Dive Height. F=Speed the bed moves

Probe Position

Next up we use G31 to define the Sensor’s offset from the nozzle in XY and the Bed in Z.

My carriage with hotend and BLTouch looks like this seen from below.

As you can see, the BLTouch is placed:

  • X is directly in line with the nozzle (X0)
  • Y is -25.3mm in front of nozzle (Y-25.3)
    • Note: if you build my xBot it most likely is further away due to the nature of the Carriage.
  • We start with a Z offset of 0.0mm in regards to actual probe activation and factual distance. This value will be adjust later on, to match our setup.
    • Important: It is important to have Z-offset at 0 before calibrating.
  • P is the value needed to trigger the BLTouch. I’ve seen and tried a lot of different values between 25 and 600 and havn’t noticed any difference. But put a pin on this one in case your probe results are inconsistent.

G31 P25 X0 Y-25.3 Z0.0 ; Z probe trigger value, offset in relation to nozzle. And trigger height adjustment

Define Mesh Grid

Next up we use M557 to define the grid on our printbed we want to probe, in order to create a Mesh the controller can use to compensate for surface inaccuracies.

We start by typing M557 then define start and end points on our X and Y axes. Example below shows how we probe from X5/Y5 to X205/Y165.

The Snn parameter defines the spacing between each probe point, where we have defined it to probe with 20mm interval.

Hint: It can be useful to start out with a big interval like 40mm, to make the probing sequence faster, and it is useful to do some manual leveling based on the probing result.
Afterwards, if you have individually driven motors, you do a fine mest for auto compensation when you can’t manually adjust it any better.

Note: There is a maximum of 400 points available for probing, so making it too fine will result in an error. If you get an error, try raising the Snn parameter.

M557 X5:205 Y5:165 S20 ; Define mesh grid

You could do your Mesh Probe sequence now, but it’s important to calibrate your BLTouch first, by calculating the Z-offset

Total Configuration – Summing up

  • Config.g changes Lets combine all our code snippets and put them in our config.g file at your current Endstop section.
  • M574 X1 Y2 S1 ; X home to min. Y home to max. NC microswitches.
    M574 Z1 S2 ; Define Z to use Probe. Home to Min.
    M558 P5 H5 F500 T4000 X0 Y0 Z1 ; Set Z probe type/mode 5. Not using on XY, but using it on Z.
    G31 P25 X0 Y-25.3 Z0.0 ; Z probe trigger value, offset in relation to nozzle. And trigger height adjustment
  • Disable the Heater PWN channel to free it up for our usage:
    ; BLTouch - Heaters
    M307 H7 A-1 C-1 D-1 ; Disable the 7th Heater to free up PWM channel 5 on the Duex board.
  • New Configuration Files
    Regardless of how your setup looks we also created a deployprobe.g  and a retractprobe.g file.

    • Deployprobe.g
      M280 P7 S10 I1
    • Retractprobe.g
      M280 P7 S90 I1
      These files are used to execute our probe as needed.

Note: If you use Duex2/5 you do not need the i1 parameter

    • Macros
      While not strictly necessary it comes in very handy to have created these:

      • Alarm Release + Pin UP
        M280 P7 S160 I1 ; Alarm Release and Push-Pin UP
      • Pin Down
        M280 P7 S10 I1 ; Send PWM channel 7 the s10 (angle) command
      • Pin Up
        M280 P7 S90 I1 ; Send PWM channel 7 the S90 (angle) command
      • Self-Test
        M280 P7 S120 I1; Send PWM channel 7 the S10 (angle) command
      • It isalso very usefull to creeate macros on various places on your bed. Ie in the front corners, center of bed and center rear and so on, depending on your setup.

Note: If you use Duex2/5 you do not need the i1 parameter

Calibrate our sensor.

Now is the time to define the Z-offset parameter in the G31 command in our config.g which looks like this right now:

G31 P25 X0 Y-25.3 Z0.0

Find Z-offset:

  1. Move your sensor to around the middle of the bed. You might even want to make a Macro for this, as it can be usefull for many different cases.
    1. Herer’s a simply macro I named Move to Centerbed, where I home X and Y first:
      G28 XY
      G1 X100 Y120 F4000 ; Move probe to middle of bed
  2. Move Z untill your nozzle is about 10cm (4 inches) from the bed.
    1. Be ready to click the Emergency Stop in case the probe misbehaves.
    2. Now issue G30 command.
    3. Your BLTouch should now send the Pin Down and your bed should now move up (or nozzle down) untill the BLTouch is triggered.
    4. Hit the Emergency Stop if it didn’t stop or the Pin didn’t drop down.
      1. Go through your deployprobe.g if the Pin didn’t drop down.
  3. With #2 successfull you put your sensor over the middle of the bed and jog Z axis untill your nozzle is touching the bed.
    1. Note: If it refuses to move as it has reached Z-minima you can type in G92 Z5 to tell it, that you are 5mm from Z=0.
  4. Once your nozzle just touched the bed tell the machine we are at Z=0 by issuing:
    G92 Z0
  5. Move Z 10mm away from nozzle
    G1 Z10
  6. Now send G30 S-1 at which point the Pin drops down and the z-axis closes the gap until the BLTouch is triggered. Z now stops moving and reports the current position without changing anything. Note down the reported value.
  7. You might want to repeat the steps 4-6 a few times to insure consistency. I personally just did it 2 times and later did final adjust by looking at print starts.
  8. Mine reported the following:
    G30 S-1
    Stopped at height 0.980 mm
  9. This means I’ll change the Z parameters in the G31 line from 0 to 0.98.
    G31 P25 X0 Y-25.3 Z0.98
    Important: The higher Z value the closer you move the nozzle and bed to each other! It’s better to have a value too low here than too high to avoid the nozzle and bed doing a mating game when homing. 
    Important: If you later redo the offset method you must set the offset to Z0 before starting or it might lead to strange results I’ve found on some occasions.

Run Mesh Grid Compensation sequence

Now that we have all our parameters in place we can run a Mesh Probe Sequence by clicking the “Run Mesh Grid Compensation” via the Drop Down Menu, or just type in G29

This Mesh Grid consists of a lot of X, Y and Z coordinates. It can be very helpfull to use this to do some manual adjustment of the Z plane. Ie, meaning you try to make your printbed as level as possible manually by running some faster rougher sequences, and then use a final high resolution mesh sequence when done.

The first Mesh Probe sequence I ran at 11:23 had a mean error of 0.182 and a deviation of 0.084. In normal words the rear bed was a tad higher than the front, so I gave the center rear screw half a turn and did the sequence again. This time the mean error went down to 0.077 and the deviation also decreased a good deal.

You can hover the mouse over the probe points to see the XYZ coordinates.

By Running the mesh grid compensation sequence by either clicking in the menu or typing G29 it will be saved into the file heightmap.csv and be activated.

Save Custom named height maps

If you use multiple different surfaces as I do, you might want to have several heightmaps on hand.

You can use M374 to save the heightmap with a different name than the default heightmap.csv. Below I’ve saved the heightmap as “bareplate.csv” as this is directly onto the surface of my PEI-Coated aluminium plate.

I’ll be making different files for when I’m using glass for printing Nylon, FlexiPlate for PLA and so on.

In order to use one of our custom named heightmaps we can not just use G29 S1 to load the default map, but instead we use M375 to call up our desired height map:
M375 P"bareplate.csv"

Before Printing

Before we can wrap up our configuration we need to adjust our homeing files to match.


The Gcode G30 is actually enough to deploy the probe and make your Z axis home. I’ve added a line to move the bed to Z=10 after probing like so:

; Homez.g
G30 ; Do a single probe to home our Z axis
G90 ; Make sure we are in absolute mode

G1 Z10 F6000 ; Rapidly move the Z axis to Z=10.

The G30 just probes and set Z to 0. The Offset we configured previously adjust the distance to match.


I’m a bit confused here actually as it seems the machine uses homeall and then issue homez even if we havn’t made references to it in the homeall.g file.

Can anyone shed light on this behaviour?

Slizer startup gcode

In order to actively be using our Mesh and use the Sensor when we print, we need to add some lines to our slizer’s startup gcode

  • Here I’m first homing my X and Y axis.
  • Then clearing any Bed Transform I might have in place, as it would otherwise affect the probing.
  • I’m then moving the probe to be at the middle of the bed. If it oozes, you might want to omit or change this.
  • I’m then issuing the G30 command which brings my Z axis to close the distance between nozzle and bed and do the single probe.
  • Now it’s time to load the heightmap we have created previsouly using our Mesh Grid. It is important this comes after the bed probe.
    • You either use G29 S1 to load the default heightmap.csv or you use the M375 to load a custom heightmap.
    • I’ve loaded my custom heightmap below.
  • Finally I’m moving the Z to 20

G28 XY ;Home XY
M561 ; Clear any bed transform that might be in place
G1 X104.5 Y130 ; Move Probe to middle of bed
G30 ; Do a single probe
M375 P"bareplate.csv" ; Load my custom heightmap. Otherwise use G29 S1
G1 Z20.0 F6000 ; Move Z to 20

Multi Z-motors setup using bed.g

Now we have all the common stuff in place we are ready to look at the functions where we use the bed.g file to define how our individual Z-motors are placed and react when probing.

Note: Remember I’m talking from a Box Printer perspective here, but you can use it just fine for Tower Printers  just keep my references in mind!

In order to use the multi z-motor functione we use he multi-probe gcode G32 when homing Z, which calls on the macrofile bed.g where we have multiple probe points instead of just using the single probe point defined via M557 in our config.g file, using the single-probe command G30.

Z-Leadscrew placements

In order to put in some meaningfull coordinates in bed.g we need to know where our Z-leadscrews are in relation to our probe.

Here we can see the placement of my 3 leadscrews on my xBot printer, in relation ot the fingerscrews on my bed.

I used the rear center screw to pinpoint the exact XY coordinate of the probe in relation to the screws.

The numbers in the red circles are the placement and numbering of my Z-motors, while the square boxes indicates the coordinate and probe sequence of my bed.g file.

  • The bed.g starts by issuing a M561 to clear any bed-plane fitting/transform we might have in place by a previous probing.
  • Next we clear any heightmap we might have in effect as the height map should only be loaded after performing our bed leveling probe sequence.
  • Deploy our probe using M401 which simply call on our deployprobe.g we created earlier.
  • Now we come to the business of defining where we probe our bed. We issue the G30 command 3 times, starting with motor 1 through 3.
  • It is 3 times as I have 3 independent Z motors.
    • Important: It is very important we use same sequence as we will be defining the leadscrews in our config.g (next step) file using M671
  • The S3 we have listed after our third line of G30 is crucial to the function, as it must be equal to the number of probe points/individual leadscrews we are using.
    • The strange Z-9999 is there as a Z value less than -9999 causes the machine to probe at the current point to get Z, rather than using the given value.
    • If an S field is specified (e.g. G30 P2 X100 Y165 Z-9999 S3) the bed plane is computed for compensation and stored which is exactly what we want here!
    • if using a Tower Printer with 2 individual Z motors, you would put S2 after the last line instead.
  • Now that we have probed one time pr leadscrew and set it up for computation we retract our probe using M402, which just calls our retractprobe.g file.

; bed.g
; Called using G32
; Called to perform True Autolevel using 3-point probe
M561 ; clear any bed transform
G29 S2; Clear bed height map

; Probe 3-point
M401 ; Deploy probe - deployprobe.g
G30 P0 X200 Y0 Z-9999 ; Front Right
G30 P1 X0 Y0 Z-9999 ; Front Left
G30 P2 X100 Y165 Z-9999 S3 ; Center Rear
M402 ; Retract Probe - retractprobe.g

Define XY Coordinates in config.g

When using the bed.g file to setup multiply points to probe in relation to the leadscrews, we need to define the XY position of the leadscrews in our config.g file.

These coordinates will be outside our printing area and can as such be much higher and even have negative values.

In order to define these, we use the M671 which I’ve placed above my Endstop section in the config.g file.

We obviously also need to know where our leadscrews are placed in relation to our nozzle, for which I’ve made this drawing:

The coordinates we fill in using M671 are the XY coordinates placed at each of the round numbers, in that order.

Remember you can do this with just 2 individual Z-motors, and as such do not need 3 for full autolevel. Using 2 motors will only level the bed on one axis though, but that is still very neat.

The actual syntax used here is a bit strange as we start by issuing the M671 command, then type the axis in question (X at first), followed by the 3 X coordiantes, seperated by :
Next up we do the same with the Y coordinates and terminated by the optional S3 parameter – not to be confused by the S3 we used above!

I used 3mm in the S as I had some issues with Z sync not working as I wanted it to do. It’s defaulting at S1, so you might do fine without specifying anything for S.

; Define the X and Y coordinates of the leadscrews.
; Must come after M584 (Set drive mapping), M667 (Select CoreXY Mode) and M669 (Choosing Kinematics type)
; Motor order: Front right (1), front left (2), rear center (3).
; Snn Maximum correction in mm to apply to each leadscrew (optional, default 1.0)
M671 X256.6:-53.6:100 Y239.10:239.1:65.50 S3

Lets have a look at Homing using a Probe

Now everything is setup according to our system and we are ready to do an autolevel for the first time.

I’m writing Autolevel as my machine is doing an actual true autolevel. If you use 2 z-motors you “only” level it on one axis where as the Mesh Grid applied after the autolevel is our Auto Compensation.

You need to have homed the X and Y axes before starting, but aside from this, you only really need to type in G32 to do the magic.

It will do a probe sequence on the 3 coordinates defined in the bed.g file and calculate the Z-plane based on these measurements and coordinates of the leadscrews as we just defined in our config.g using M671

If you wonder, my homez.g file just home using a single probe action and rapidly moves the bed down again. I have this in place if I want to redo offset.
; Homez.g
G91 ; Relative Positioning
G90 ; Absolute Positioning
G1 Z20 F4000

Slizer Startup and Endcode Examples

As a rounding up on this post I’m posting my start and end codes on 2 machines:

Single Z-Motor Machine

I’m using Cura as my slizer, so I do not need all the “wait for temperature” gcodes of some other slizers, as these are automatcially in place – except for Chamber Heater, which you must add manually if using such a one.

; Startup Gcode
G91                        ; Relative Positioning
G1 Z-1                     ; Move Z down 1mm
G90                        ; Absolute Positioning
G28 XY                     ; Home XY
M561                       ; Clear any bed transform
G1 X104.5 Y130             ; Move Probe to middle of bed
G30                        ; Do a single probe
M375 P"flexiplate.csv"     ; Load heightmap (you can use G29 S1 instead)
G1 Z20.0 F6000             ; Move Z to 20
G1 X5 Y5                   ; Move Head to front left
G92 E0                     ; Zero Extruder
G1 F200 E15                ; Prime the extruder
G92 E0                     ; Zero Extruder


; End Gcode
G10 P0 R-273.15 S-273.15     ; Turn off Tool0
G10 P1 R-273.15 S-273.15     ; Turn off Tool1
M140 S-273.15                ; Turn off Bed
M106 S0                      ; Object fan off
G1 Z210                      ; Move Z to Z210
G92 E0                       ; Zero Extruder
G1 E-2 F300                  ; Retract 2mm
G92 E0                       ; Zero Extruder
G28 XY                       ; Home XY
M84                          ; All motors Off

Triple Z-Motor Machine

And my startup gcode for my xBot triple Z-motor machine.

; Startup Gcode
G91                      ; Relative Positioning
G1 Z-1                   ; Move Z down 1mm
G90                      ; Absolute Positioning
G28 XY                   ; Home XY
M561                     ; Clear any bed transform
G1 X104.5 Y173           ; Move Probe to middle of bed
G32                      ; Start 3-point probe sequence
M375 P"bareplate.csv"    ; Load heightmap
G1 Z20.0 F6000           ; Move Z to 20
G1 X5 Y5                 ; Move Head to front left
G92 E0                   ; Zero Extruder
G1 F200 E20              ; Prime the extruder
G92 E0                   ; Zero Extruder

My Endcode for xBot

In this one I home it to XY and U. The U is my virtual axis I’ve made for Z in order for it to be able to home to Z max, which I can’t otherwise do.

This doesn’t work with the setup for the single Z-machine. I have not yet had time to see if I can get around this, by using bed.g even though I don’t need it for that one.

; End Gcdoe
G10 P0 R-273.15 S-273.15   ; Turn off Tool0
G10 P1 R-273.15 S-273.15   ; Turn off Tool1
G10 P2 R-273.15 S-273.15   ; Turn off Tool2
M140 S-273.15              ; Turn off Bed
M141 S-273.15              ; Turn off Chamber Heater
M106 S0                    ; Object fan off
G92 E0                     ; Zero Extruder
G1 E-2 F300                ; Retract 2mm
G92 E0                     ; Zero Extruder
G28 XYU                    ; Home XY and U to Z max
M84                        ; All motors Off


Gcodes Used

Here’s a list of (some of) the M and Gcodes introduced in this post:

  • G28
  • G29 – Detailed Z-Probe
  • G30 – Single Z-Probe
  • G31 – Set or Report Current Probe Status
  • G32 – Probe Z and Calculate Z-Plane


  • M280 – Set Servo Position
  • M374 – Save height map (with alternate name)
  • M375 – Load (custom) height map
  • M557 – Set Z Probe point or define probing grid
  • M558 – Set Z Probe Type
  • M561 – Set Identity Transform (Reset any Mesh probes or adjustments in place)
  • M671 – Define positions of Z leadscrews or bed levelling screws
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xBot Medium – Mechanical Parts – (BOM cont.)

I’ve previously went over the Custom parts and Electronics and Electrical parts in two seperate posts needed to build the xBot-Medium Printer. This included motors and limit switches, so everything with current in it.

In this final BOM post I’ll list the inert mechanical parts.

I’ve set up a xBot-Medium Github Repository where the files can be found for this project. As I havn’t finished it yet, all the files aren’t there, but they will be! Only the .STP files for the Dibond frame pieces and some a few for printed parts are missing, so it’s pretty much complete allready.

A complete BOM file is in place in the Github Repository.

This post is sorted in the following categories:

  1. Parts for the XY Axes
    1. 200-GT2 Belts
    2. 20-GT2 5mm bore Pulleys
    3. 20-GT2 8mm bore Pulleys
    4. 610-GT2 Belts
    5. Sliders
    6. LM6LUU
    7. Spacers
    8. Flanged 688 bearings
  2. Parts for the Z-liftplate
    1. Anti-backlash nuts
    2. 12mm flanged bearings
    3. 8mm flanged bearings
    4. Fingerscrews
  3. Screws and nuts
    1. Screws for Z-Stage
    2. Screws for the Frame
    3. Motors
      1. Motorshields
    4. Limit switches
    5. Under the machine
      1. Z-Rod brackets
      2. Connectors
      3. Duet WiFi and Duex Mounting
      4. Powersupply
      5. Chamber Heater
      6. SSR

1) Parts for the XY axes

Lots of parts going into this contraption. It IS one of the key parts to make this printer design so successfull. It’s not really that complicated once you wrap your brain around how it’s working though.

200GT-2 Belts

Price # €0,33 total for 2pcs: €0,66 from Robotdigg

We basically have 1 motor pr axis. They each use a short 200-GT2 belt to push and pull at the end of one 8mm rod pr axis.

20-GT2 5mm bore Pulleys

Price each €1,33 for both from RobotDigg €2,65

In order for our motors to make use of the 200-GT2 Belts, they each need a 20-GT2 Pulley with 5mm bore.

20-GT2 8mm bore Pulleys

Price for 10psc at RobotDigg: €6,22

At the end of each 8mm rods there is a 20-GT2 pulleys connected to the opposite 8mm rod for that axis with the closed 610-GT2 belts.

At the furthest end of 1 rod of the X and Y axis, there is an extra 20-GT2 Pulley, where the belt from each motor is connected to.

It means when motor Y pulls at the end of Rod 1 for Axis Y that entire rod turns around. Via the 20-GT2 pulleys in each end, and the connected 610-GT2 belts makes the corrosponding second Y rod turn synchronized.

Same goes on for the 2x 8mm rods for the X axis.

610-GT2 Belts

Price for x4 from RobotDigg: €2,98

We have 4 of these 610mm closed/endless GT2 belts which are used on each end of each pair of 8mm rod for X and Y axis.


Price for 4sets €8,6

1 set is made up of 2 plastic parts a spring and a selfgraphite bushing 30mm long 8mm inner 12mm outer diameter

Sliding along each 8mm rod, there is a “Slider” which slides along the rods by utilizing a 30mm long 8id/12od mm self graphite bushing.

Each Slider can be split in two in order to run one side of the belt through the middle of it. The belt is is fastened in the middle using a small spring, which also helps ensuring the right tension and even makes up for some small inaccuracies you might have in the axes.

Each slider then runs along/on an 8mm rod. Pulled long by its own 610-GT2 belt. Each axis consists of 2 sliders connected with a 6mm rod where the Carriage with hotend is located on the cross-section between the 6mm rods of the X and Y axis.

The rods rotate as part of how they pull the sliders, which is the reason for the bushings as ball bearings would break down here.
The bushings also means extremely quiet running, which is just awesome.

Contrary to the sliders, the Carriage uses 2x LM6LUU ball bearings as the 6mm rods aren’t rotating, and also to provide a bit of compensation for tiny inaccuracies in the construction – ball bearings have build in about 1% give.

It all means there is equal identical directional force being applied on both sides of the carriage, so we do not experience any form of skew on the carriage as with CoreXY.

The bushings are listed as not requiring lubrication, but they really do benefit from a bit of lubrication. Especially if you buy cheap rods with bad tolerance. Many cheap rods are too big, which might be nice for ball-bearings (remember the 1% tolerance), as it gives a tighter fit, but with bushings it just means more friction, noise and potential bad print quality. You might also experience problems inserting the flanged bearings onto the ends of the rods, if you buy cheap rods.

Use acid free clear and thin sewing or cycle oil. Or PTFE spray, which I’m using.


You can get all sorts of upgrades which are mostly relevant if you tend to pick your machine apart a lot.

In those cases the plastc sliders rapidly degrades and after a few times they no longer grip onto the 6mm rods very well.

For such cases, you can get various different Aluminium sliders. I have these linked parts, but other variations also readily available now.

They do cost over €30 though for a set. Beware the dimensions for rods as some of these use 8mm cross rods instead of the 6mm we use.



Price for 2: €3,16

As decribed above, we need 2x long 6mm ball bearings for our Carriage. You might be tempted to use Bushings here, but if you have the slighted misalignment they are going to make grinding noises and ruin the print. These bearings also help compensate a bit for misalignment, as the balls have a build in 1% give.

You might want to buy extras, as you need to change them now and then – when they begin to rattle.


Price for a bag €4,7

We need some accuracte plastic spacers M8,2x14x5 (inner, outer, height) at the end of all our 8mm rods for the X and Y axes. They go between the 20-GT2 pulleys and the outer flanged bearing in the side of the frame.

It’s important they are uniform in size, so I really prefer to buy these instead of printing them. Especially since a bag with 200x spacer 5mm thick costs less than €5. Such a bag has served me in multiple builds. You can’t use a spacerset from Ultimaker 2 as we use more spacers than they do. It wouldn’t save us any money regardless if we could use it though.


I don’t even know if you can get them in pieces 15 or 25mm long, but this listing shows the fewest, longest pieces possible.

It is 150mm total, so if you get a back with 5mm long/wide spacers, you need 30 of those.

  • 4x 25mm long
  • 2x 15mm long
  • 2x 10mm long

Flanged Bearings

Price for 8 at RobotDigg €3,32

Our 8mm rods are inserted into a single F688 Flanged Bearing at each end, so we need 8 of those.

If you find you can’t get them onto your 8mm rods I’ll wager it’s due to bad quality rods and you should demand the money back.

2) Parts for the Z-liftplate

We allready went over the Z-liftplate and the heated bed itself in the first 2 posts, and we’ll look at the bits and pieces here.

Antibacklash nuts

Price for 3 from RobotDigg €7,46

We are going to be using 3 of these nuts for our Z-stage. We use these as they are cheap and direct replace for standard lead scerw nuts. The reason for using Anti-backlash is to avoid issues with Backlash which might show some, especially when doing Z-lift during prints, but also after a while, when the nuts and/or rods are a bit worn.

The Anti-backlash nuts compensate for the wear and tear and also for bad quality the lead screws, and even the nuts themselves, might have.

The partnumber is B-ABN88 where the 88 is 8diameter and 8mm travel pr rotation. Also call “Lead”.


You might wonder about what Backlash is, so you should head over and read this nice post about it.

Both these images are from the post on Backlash on

12mm flanged bearings

Price for 2 LMK12LUU €4,64 from RobotDigg

We use 2 of these to for the rear end of our Z-liftplate. They provide a nice large surface area to use as stabalizer for our plate as it goes up and down.

8mm flanged bearings

Price for 2 LMH8UU: €4,14

We use  2Pcs of these LMH8UU ellipse/oval flanged ball bearing to support each of the front Z-axis motor.


Price for 3 sets €3,39

We need 3 sets of these to adjust our Heated Bed.

Each set consists of a fingerscrew (which comes in gold and silver) a powfull spring and a m6 washer + 20mm m3 flat head screw to sink into the countersunk holes in the heated bed


3) Screws and Nuts

You can get a complete list of all items needed, included a listing of the screws and nuts from the xBot Medium Github Repository. Look for the xBot Medium-BOM.pdf file

Screws for Z-stage

A complete listing of screws for the Z-stage. I’m not listing price for these.

Only thing of note here is the fact that we are using m3 square nuts for the frame as these sits better in the cutouts. Aside from this, all parts are totally standard.

Screws for the Frame:

  • Right side:
    • 12x m3 16mm Button Head Screws
    • 12x m3 Square Nuts
  • Left Side
    • 12x m3 16mm Button Head Screws
    • 12x m3 Square Nuts
  • Front
    • 5x m3 16mm Button Head Screws
    • 5x m3 Square Nuts
  • Back
    • 6x m3 16mm Button Head Screws
    • 6m m3 Square Nuts
  • Door Hinges
    • 4x m3 10mm Button head Screws (might change)


  • Z-Motors
    • 12x m3 10mm Button Head Screws
  • XY Motors
    • 8x m3 30mm Button Head Screws
    • 8x m3 Metal Spacer
  • 8x m3 10mm Button Head Screws

Limit Switches

You can either use 2.5mm screws + a nut or an m3 screw if you tap the switch first. I like to tap mine.

  • Z-Max Limit Switches
    • 6x m3 10mm Button Head Screws
    • 6x m2.5 12mm Screws
    • 6x m2.5 nuts
  • X and Y Limit Switches
    • 4x m3 10mm Button Head Screws
    • 4x m2.5 12mm Screws
    • 4x m2.5 nuts

Under the machine

Z-Rod brackets

  • 12mm Z-rod Brackets
    • 4x 12mm m3 Button Head
  • 8mm Z-rod Brackets
    • 4x 12mm m3 Button Head


  • Front USB
    • 2x m3 10mm Button Head Screws
  • Rear USB
    • 2x m3 20mm Button Head Screws
  • Power Connector

Duet WiFi and Duex Mounting

  • 8x m3 10mm Button Head Screws
  • 8x m3 8mm Button Head Screws

Power Supply

  • 4x m4 10-12mm Button Head Screws

Chamber Heater

  • 4x m4 20mm Button Head Screws


  • 2x m4 20mm Button Head Screws
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xBot Medium – Electronics and Electrical parts (BOM cont.)

In this post I’ll continue describing what is needed to actually build the xBot-Medium printer. Last time I talked about the Custom Parts, and this time it will be about the Electronics and Electrical parts.

I’ve set up a xBot-Medium Github Repository where the files can be found for this project. As I havn’t finished it yet, all the files aren’t there, but they will be! Only the .STP files for the Dibond frame pieces and some a few for printed parts are missing, so it’s pretty much complete allready.

This post is going to be about the Electronics and Electrical parts we need for the xBot-Medium 3D Printer. I’ll list the Mechanical parts in a later post.

All “BOM” posts here on my blog are going to be condensed into a BOM in list form on the x-Bot-Medium Github Repository.

Some parts are both electrical and mechancial, like the motors, and such items are added to this post, while the Mechanical parts post are going to be the completely inert like the various pulleys, belts, nuts and such.

This is mostly going to be a list without a whole lot of exlanation to it.

xBot Medium electrical and electronical listing

  1. Duet WiFi
    1. Thermocoupler Daughterboard
  2. Duex5
    1. Consideration if choosing Duex2
  3. PanelDue 5″
  4. BLTouch SMART
  5. Heated Bed
    1. AC Silicone heater 500w
    2. SSR
  6. 3x Z-Motors
  7. XY Motors
  8. Extruder(motors)
  9. Chamber Heater
    1. 3x 30mm fans
  10. 2x 30mm fans for Printed objects
  11. Powersupply
  12. LED – RGB
    1. Manual on-off rocker
  13. Various
    1. Limit switches
      1. Long arm
      2. Short arm
    2. Front USB power out
    3. Rear USB for Controller access
    4. AC Power plug and on/off
    5. GX12 and G16 connectors
  14. Carriage
  15. Hotend
    1. Thermocoupler
    2. Plated Cobber nozzle
    3. 40w Heater Cartridge
  16. Untill next time


Duet Wifi

As the main controller, I’m using the Duet WiFi from duet3d.

Price: inc 20% vat: €162,3

While the price does seem rather high, you should take all the features in consideration.

Best quality of any controller. Simple as that. Both regarding features and quality. There are many safety features build in, like it doesn’t burn if a driver or sensor is accidentially unplugged while power is on, which is the main cause of dead electronics for many people. It doesn’t require active cooling as it get rids of the heat through PCB surface – active cooling is always a good idea though, but it’s not a requirment like pretty much all machines using pololu drivers.

It’s top of the line quality and uses 5x TMC2660, which are the highest end drivers you can get on any controller. They are very powerfull SilentStep Sticks (big brother to TMC2100/TMC2130) and can drive up to 3amp pr driver. Most people end up going out and spend money on silent step sticks anyway, which easily ends up at €50 for a set of those – and you can’t buy TMC2660 pololu sticks.

At some point many people start looking at a remote way to control and monitor the printer, and end up going out to buy a Raspberry Pi, which is another €35.
Regardless of what solution people use they don’t ever get close to the integrated webserver allready in the Duet WiFi. It’s hugely powerfull and very responsive. Has a ton of usefull information, and you even use it to setup the entire printer, so no need to compile firmware on your printer and then transfer using USB.
Since it’s integrated it also talks directly to the controller instead of using USB.
It also provides for real time changes in setup of most settings. Change fans, extrusionrate and LED using sliders etc etc.


From the official Duet3D Features page.

Feature list
From site

The DuetWifi is an advanced 32 bit electronics for the control of 3D printers and other CNC machines. It has the same features as the Duet Ethernet other than providing a WiFi connectivity rather than ethernet, full feature description is available on our wiki, in summary:

  • Powerful 32 Bit Processor
  • Dedicated Wifi module
  • Super quiet TMC2660 stepper drivers, up to 256 microstepping.
  • Dual extruders on the main board, up to 5 more extruders on the expansion board.
  • High Power rating: Each stepper driver is capable of 2.8A motor current, currently limited in software to 2.4A. The bed heater channel is specifically designed for high current (18A).
  • Connect via PC, tablet or smartphone on the same network to the on board web interface.
  • Setup your printer and update the firmware through the web interface.
  • Expandable up to 7 extruders with Firmware support for mixing nozzles and remapping axes to use high power external drivers.
  • Support for the PanelDue: a full colour graphic touch screen

Thermocoupler Daughterboard

Price inc 20% vat: €31

To be honest: Im not a fan of this design (put mildly)! I find it rather cumbersome how it’s stacked like that, and it can easily fall out if mounted upside down.. and thus prone to failure. The small terminals are very unforgiving as well, so can be hard getting a good connection.

As much as I find the price warranted for the Duet WiFi, I do look at these things the opposite way…

But while we supposedly can use 3rd party solutions I havn’t managed to make anything work, or seen anyone making anything work, so if you want to use Thermocouplers (top board below) or PT100 (big lower board) you have to use the official Duet Daughterboards.

If you know of a sure way to make 3rd party boards to work, please let me/us know! Not just a link to the right chip, it must be a complete solution 🙂

Photos from official Duet3D shop.

Usage in build:

1-2x Thermocoupler Daughterboards, price total €31-62 inc 20% vat!

I’m going to use Thermocoupler for my hotend and for the heated bed as they react much faster and are much more accurate than standard Thermistors. It’s also a must for hotend if you want to print over 280c as a thermistor dies at 290c or so. Thermocoupler and PT100 sensors don’t tend to die on you like Thermistors can either, so it’s a one-time purchace.

I’m still a bit undecided as to wheter I want to use a Thermocoupler or a plain Thermistor for temperature sensing in the chamber. It’s really a high price to pay for this, but lets see if I get any sponsoring for the project.

I used to use PT100 before starting to use Duet, but the PT100 daughterboards were much, much more expensive than Thermocoupler boards, so that is the only reason I use Thermocoupler. There is no actual difference in usage. PT100 should be less prone to suffer from interference, but wheter that transfer over in reality is always questionable 🙂


Price: inc 20% vat: €111,6 for Duex5
Price: inc 20% vat: €77,8 for Duex2

The Duet WiFi has 5 drivers, so you might actually do ok with Duex2 if you only want 1-2 Extruders. There used to be other differences, but not anymore.

Driver assignments

  • 1 for X
  • 1 for Y
  • 3 for Z
  • 1-2 extruders. (Can use Duex2)
  • 3-5 extruders. (Need Duex5)

The Duex2/5 boards has the following features:

The Duex2 and Duex5 has the same feature list aside from the first 4 points here, listed as 2/5:

  • 2/5 additional TMC2660 stepper motor drivers with stall notification.
  • 2/5 additional extruder heater outputs.
  • 2/5 servo outputs with 5V power and 5V signal levels, sharing control channels with the heaters, so you can use unused heater channels to drive servos.
  • 2/5 additional endstop inputs with indicator LEDs and 3.3V/5V voltage selection. These are also usable as outputs.
  • 6 additional controlled fan outputs, also usable for driving LEDs etc. The output voltage may be switched between 5V, 12V and VIN.
  • 4 uncommitted general purpose I/O pins.
  • 12V switching regulator, for generating a 12V supply for fans, LEDs etc. when the VIN power is higher than 12V.
  • 5 additional thermistor inputs.
  • Support for 2 more thermocouple or PT100 daughter boards, supporting up to 4 more sensors.
  • Optional 5V external power input for powering servos, fans etc.

Official complete feature list and comparison.

Considerations if choosing Duex2

While researching this I learned the difference between Duex 2 and 5 is only the 4 first points in the above list.

I thought Duex2 would have less fan headers as well. Last year Duex2 also didn’t come with the 12v switching regulator.

It all mean you can pick Duex2 if you don’t plan on using more than 2 extruders, but have to pick Duex5 if you plan on using more than 2 Extruders.

PanelDue 5″

Price: out of stock?
Price Filafarm; inc 19% VAT: 4.3″ €99,89
Price Filafarm; inc 19% VAT: 5″ €109,9

Lets say it as it is: You don’t really need a screen. The Web GUI is just that awesome!

I used my first Duet WiFi printer for over a year without getting around to using the PanelDue I had lying around as the Webinterface is just so super nice and lets face it, these things are really expensive as well.

Price vs performance

It really is a matter of usage preferences as they are stocked full up with features, like:

  • Buying a PanelDue gives you external SD card access (the big SD card type).
  • True serial connection, so full control of the machine (unlike cheap MKS displays which doesn’t really talk to the controller, but only sends commands
    • I mention MKS as someone has worked up an alpha firmware for them, so they might be able to work as standin for PanelDue (using serial)).
  • One awesome thing, which I havn’t seen mentioned elsewhere is how the macro’s you create in Web GUI are transferred to the display as menues and buttons completely automatically. This is awesome, and a super way to stack up on functions: ie i you often do some thing like changing filament, you can make a macro to heatup and retract etc.

Here you can see how I made a few macros to test movement on my previous printer project:

I use the display a lot on my BeTrue3D Printer due to it’s many extruders, but on my normal primary machine I only really use display to check up on temperature at a glance and such.

If that is how you use display as well, you might want to try using the machine without the LCD. Might just use an old phone or tablet, although the response would not be almost instant.


Price Filafarm inc 19% VAT €39.90

We use this sensor to ensure correct distance betwee hotend nozzle and print bed and also to take advantage of our 3-motor Z-axis for complete true autolevel function.

Since the xBot-Medium is 10mm deeper than an Ultimaker 2+ we can now squeese one of these in in front of our hotend.

It’s a combination of a normal limit switch functionality and a servo motor to raise up this switch after engaging, which was a somewhat common solution some years ago. ANTClabs combined these things an came up with the BLTouch.

Lets start by saying: Don’t buy copies. Just don’t. There is a huge difference in quality and you really want these things to work 100%.

If you look around you find a lot of people having problems.. when you dig in, you find that all the people having issues are using copies.

You also want the newest version, called SMART. You can check the difference by the sticker labeled SMART, by the tip of the probe-pin and the BLTouch also needs to have serial number printed on it, which can be verified a



Heated Bed

Price from inc VAT €54-71

I’m using a 5mm thick PEI-Coated Aluminium bed with an AC Silicone heater under.

You can pick from 2 different qualities and several different colors and even get logo or text lasered into the surface.

The price at €54 is the lowest price uses a cast aluminium plate, while you can get a milled plate at €71. I’m honestly not sure what my plates are, as I couldn’t choose quality back then.

Be sure to pick the Ultimaker 2 257x229x5mm under dimensions.

Email the owner to agree on color and price etc, and to be sure the plate comes with holes for fingerscrews… it should as he’s using my drawings for these plates <wink>

I print PLA, ABS+ and PETG on it with great results. I’ve heard people say PETG sticks too hard, but I’ve had no problems with anything.
I do have seperate glass plates I put on top of my bed when I print Nylon (glue on glass). Some PLA don’t want to stick very well to this plate unless I heat it a lot, so sometimes use glass for PLA as well.

AC Silicone heater 500w

Price from Keenovo €40,5

Specifications: 200X240mm 500W 220V build in Thermocouple Type-K sensor.
Link to same version with Thermistor instead of Thermocouple sensor.

As most everything else, there are different levels of quality, and the same goes for Silicone heaters. I’ve come to like the market leader Keenovo heaters and am using one of their heaters for the xBot-Medium printer.

They come with build in wires for the heater itself and wires for Thermistor. I’ve asked them if they can build in Thermocouple instead, which they agreed to do, so now I’m just waiting to recieve my super nice Heaterpad.

These pads comes with high quality 3M tape preapplied to one side.


Price (RobotDigg) €4

SSR10A DC-AC Solid-state Relay

There are many copies of Solid State Relays (SSR) on the market, so make sure to buy from somewhere you trust. I’ve bought SSR from RobotDigg several times, and always recieved good ones.

Make sure you buy one labaled as DC-AC as it is controlled by DC from our Duet and then in turn controll the AC input to the bed. The AMP is really only important if you use a DC-DC SSR – ie if you have dedicated DC powersupply for your bed, then the SSR must be able to handle the amount of amperage you put through it.

3x Z-Motors

Price from RobotDigg: 3x €26,7 = $80
SKU: 17HS3001-280N w Lead Screw: 280mm long, Tr8x8(P2)

Many people are using various couplers, but I really prefer using motors with embedded lead-screws. Seems the Quality Control is much better on these than the loose lead screws we can buy. At least if we don’t go out and pay a lot of money for them.

Regardless though, we need motors with embedded lead-screws to take advantage of our entire Z-distance. If you use a coupler you would sacrifice about the length of the coupler on Z axis height.

These motors comes with a POM nut, but we can really use it as they are too large to fit in there. I could have modified it some I gues, but I also really want to use the anti-backlash nuts instead, which are cheaper to replace in case of wear and tear.

Specifications of the motors

Threaded Rod NEMA17 Stepper body 40mm lenth, 280mm Tr8*8 Leadscrew and POM Nut

The NEMA17 Threaded Rod Stepper Motor has a precision Acme Tr8*8 Leadscrew coming out directly from the nema17 as a Threaded Shaft.

200 steps per revolution (1.8 deg/step)
2 Phase, Bipolar, 4 wires
Rated Voltage 2V DC
Rated Current 1.2A
Phase Resistance: 1.7 Ohm ± 10% (20º C)
Phase inductance: 4.5 mH ± 20% (1kHz 1 V rms)
Holding torque: 0.4 N.m Min.
Motor body length: 40mm

Acme Lead Screw: 280mm long, Tr8x8(P2)
Nut: POM

The Tr8*8(P2) means it is 8mm in diameter and one revolution give a travel distance of 8mm. It has a pitch of 2mm which is the distance between the raised “edges” (leads). It has 4 starts, meaning 4 seperate “raised edges” (starts).

X and Y Motors

Price from 2x €11,9 = €23,8

For X and Y axis I can use high quality 0.9 degree stepper motors, as I made room for motors with a body length of 48mm instead of the normal 40mm length available in an Ultimaker 2

It means I can use the best quality and best suited 0.9 motor I’ve been able to find for the X and Y axes, namely the 17HM19-2004S from

You might ask: Why not just use some smaller 0.9 motor? Lots of those have high holding torque and ok amperage etc etc… good question!

Problem is however, that between the pancake model I use for my extruders and up to this powerfull full size motor, they all have really high Inductance raiting, meaning they are slow!

Additional resources


Price for 17HM08-1204S from (48mm long) €11,9
Price for 17HM08-1204S from (21mm long) €9,9

I’m going to be using 2 different motor types:

  • The same large 48mm size as used for X and Y meant for 2.85/3mm filament, as they do require some extra power.
    • See specifications just above
  • I’m using the panckage nema 17 which is just 21mm long for my normal 1,75mm filament. These are more than strong enough and really a perfect fit.
    • Note: You can use these for 2.85/3mm as well, but have to give them more current than when using them for 1,75mm. Might need to put a heatsink on it as well, which is why I simply opt to use the larger motor for the thicker filament.

This small motor is awesome! Plain and simple.

You might wonder at the small size for an extruder, but by utilizing it’s awesome specifications with it’s 0.9 degree steps and powerfull 11Ncm / 15, / 1,12kg/cm holding torque inserted into my Belted Extruder v4 it’s packing an awesome package that runs smooth, silent and cool!

Specialize brackets for my Belted Extruder v4 to quickly mount and dismount them on the xBot-Medium will be released.

Additional resources

Chamber Heater

Price eBay €4,75

I’ve bought a 200w 24v heater wiht the dimensions: 140 x 32 x 26 mm. I actually bought mine from, but it’s not available anymore.

Be sure to buy a 24v version. I accidentially bought 12v at first. It’s listed on the side of them. The photo below with measurements on it displays a 12v heater.

It’s really just a small heater element so we need some fans to blow the heat up into our Chamber.

So far I’ve just set my heated bed at 140c degrees and waited for the temperature to reach 40-50c before I started printing Nylon and such.

To be honest I don’t generally need a heater, but I wanted to add one, now that i started from scratch. All materials, including PLA and PETG benefits from higher than normal temperature at a stable level, but the inclosed box design of the printer will ensure a temperature of around 40c after printing for a while, even with no lid on it.

I’ve designed a printable fan-duct which is mounted over the hole in the bottom frame part through which the hot air is exhaused through. It needs to be printed in ABS or similar to handle the temperature.
The printed parts are or will be located on the xBot-Medium Github repository and in the Thingiverse Group for xBot-Medium once I’m done with the files.

3x 30mm fans

Price 3x €1,21 = €3,63

I’ve just bought some standard so called 24v 3010 Hotend Cooling Fan for the Chamber heater. 3fans fits snugly on it, so that’s what I did.

2x 30mm fans for Printed objects

Price 2x €2,08 = €4,17

You either need 2x 30mm fans or figure out something else. Yes, it is plenty to cool the stuff you print, so no need for 2x 50mm blower fans.
You could use 2 of the fans listed above, which I’m using for the Chamber Heater, but I’ve decided to try out some “aluminium” fans instead, which are slightly more expensive.

I normally pick 12v fans for this as it’s very hard to find good quality 24v fans, and if you do, they cost way more.

It means I just put them in series:

  1. The 24v power line connects to red wire on one fan
  2. Gnd to the black wire on the other fan.
  3. The unused pin from each fan is connected by a wire or similar.
  4. Voila, you now have your two 12v fan running in series on your 24v system.

Note: not all 12v fans can do this, but most I’ve tried do it 100%.


Price: €60

The price is approximate what you might expect to find a good Powersupply at.

If you don’t plan on using Chamber heater, you can find a good Meanwell 24v 10amperage powersupply at half the above price.

If you do plan on using the Chamber Heater you should look for a 24v 18-20amperage to make sure you have enough juice.

I’m running my primary printer on a 24v 10amp PSU which is passively cooled, ie no fans, and it never even gets temperate, so no need to go overboard.

Better to get good quality with lower amp, than buy crummy 40amp psu.

You need a relatively low profile powersupply. Not much higher than 40mm.

For the xBot-Medium I managed to win an auction for a MeanWell HPR-450-24 powersupply. This translates to 24v 450w 18.8amp

I originally believed it had temperature controlled fan, but what it has is on/off fan that activates at some % load. It’s loud, so I need to figure something out to tame is.

Additional ressources

  • Dimensions: Width 105mm, height 41mm, depth 218mm
  • Datasheet opens pdf


Price for 5m: €11,25

You don’t need RGB and I’ve always just used plain white light, but I recently learned you could use and control these using 3x FAN headers on the Duet/Duex.

I went and bought 5Meters of 24v RGB LED strip. Like normal led strips you can cut these at invertal and so make the lengths you want. 5m is plenty for several different projects.

I bought mine in the EU, so I guess you can get it at half price in China.

Manual on-off rocker

Price less than €1

Manual on/off switch for our front RGB LED light. I just like to have the ability to switch that rocker to turn the off sometimes even though the lights are programably turned on.

I hope I can just use this on the GND to the LED strip, or maybe I need it on the v+ depending on what is shared on the FAN headers, but lets see!

Just look around. It’s often cheaper to buy 2 than 1 and you might get 5 at almost the same price.



Limit switches – long arms

Price for x2 €1,12

We need 2x Limit Switches with long arms for our X and Y axes.

Limit switches – short arm

Price for x3 €1,5

If you use BLTouch sensor you don’t have to install the 3 Limit Switches as endstop at the Z-Max end, but I’ll recommend that you do.

Partly as you can use it as backup system if the sensor fails and you can use them to synchronize the axes as an initial setup sequence.

Considering the price, I see it as a no-brainer to go and install them.

Front USB power out

Price €1,12

I really like having an USB power output in my 3D Printers. It can be used for webcams, powering phone/tablet or, as my favorite, powering my small USB vacumer for cleaning up the 3D Priner interior!

It requires a custom printed part which is available with the rest on the xBot-Medium Github Repository.

This video does not show the xBot-Medium, but is a video from my youtube channel showing my current primary machine.

You could also install the USB adapter intended for the rear side in this spot instead, if you’d rather go that route. I have not yet made any adapter for this option.

Rear USB for Controller access

Price €1,79

Since we have our Duet WiFi complete enclosed under our frame we need some sort of extensions to make it possible to connect to the controller via USB in case of various update and maintenance.

It’s called an USB 2.0 B Female Socket Panel Mount To Micro 5 Pin USB Male – Cable 50cm

You can route this to the front USB port instead if you like. I just havn’t made an adapter for this yet, but it should be a simple matter.


AC Power plug and on/off

Price €1,12

You can get them in a variety of models. I vastly prefer this model with build in fuse as it removes the need for an inline fuse between the power plug inlet and the internal powersupply.

You can get them with and without light and with different colors for the rocker. The cheapest model is without light and black rocker, while the red-rocker with light is a very close second.

Be sure to wire it correctly, so it’s the live wire connection going through the fuse.

GX12 and G16 connectors

Prices at around €1 each – so totalling at around €7

If you can wait for it, then order from china, as they cost a fraction of the cost. Not just a bit cheaper, but like 1/10 price sometimes!

  • 4x GX12-4
    • We can mount 4 external extruders, each of which takes a GX12-4 pin connector.
  • 1x GX16 8pin
    • We need a GX16 8-pin for our Carriage for Hotend Heater (2p), Heatsink Fan (2p), Object fan (2p), Sensor (2p).
  • 1x GX16 5pin
    • We are using a seperate GX16 5-pin for our BLTouch sensor.
  • 1x GX16 4pin
    • We need a single GX16 4-pin to hook up our heated bed: Heater (2p) and Sensor (2p)


This is just a word used to describe the combined collection of objects driving around along with the Hotend. Ie, the mechanisms themselves, fasteners, extra fans and sensors and so on.

We allready talked about the BLTouch, which is definently a part of the Carriage.
We also went over the 2 fans used to cool our Printed Objects.


Price: E3Dv6 Full Bowden €63,6

I’m going to use genuine Full E3Dv6 1,75mm hotends. I also have a (genuine) Full E3Dv6 3mm I use when printing Flexibles as flexibles in 1,75mm just aren’t viable.

You can use some other hotend if you like, but I prefer the E3Dv6 FULL 1,75mm hotend.

  • The FULL part is important as it is made up of an aluminium heater block, a steel heatbreak and a seperate aluminium heatsink. This model has very tight control over extrusion as the seperate pieces of the heatsink (and different materials) makes for very cleanly defined heat and coldzones. Retraction is normally around 1-1.5mm only, when using bowdenThe bowden tube goes down into the top of the heatsink and into the very top of the steel heatbreak. This means the PTFE materail from the bowden is far away from the hot zone, meaning you can use temperatures way above the LITE version (280 with thermistor – 500 with thermocoupler/pt100 sensor)If you by accident pull up in the bowden while the hotend is hot, nothing happens as the molten plastic can’t get up in the space between bowden and heatbreak. The added friction created by the steel heatbreak is actually a good thing as it makes for very tight filament printing control.
  • The LITE version is not recommended in my world. It is made up of a combined steel heatbreak with embedded heatbreak. This model does not have the same tight control as the FULL as it doesn’t have as effective heatsink and because the PTFE Bowden tube goes all the way down through the heatsink and rest directly on top of the Heater block.If you by accident pull up in the bowden while the hotend is hot, the molten plastic will guarenteed slip up in the space just above the nozzle, inside the heatbreak now freed from PTFE Bowden tube. It means you (most likely / often) have to take it all apart to clean it up, to get it working again!It does not have as tight control and while the FULL only requires 1-1.5mm retract, this LITE version takes 6mm! This long retract is required as it does not have as sharply defined hot and cold ends, so lots of “internal stringing” is going on, which in turn needs to be pushed out of the hotend after each retract = not as clean print. They still print better than most other hotends, don’t get me wrong, but not compared to the FULL!

The price includes lots of parts. You can view all under what’s in the box, from where I’ve taken below photos.

Some parts to mention: The nice Steel heatbreak and aluminium heatbreak with the bowden coupler, full kit with fan shroud, fan, blue silicone caps, thermistor and 24v (30w) heater.

There’s also a single 0,4mm standard Brass nozzle included.


Price €12,5

I’m not a huge fan of Thermistors. Both because they can break, but also because they aren’t that accuracte and I print at higher temperatures than they can go (300+), meaning I’m using a Thermocoupler sensor instead.

E3D has begun selling these, which works fine with the Duet. Duet sell these same Thermocouplers from their store now as well.

It does require you to use a Thermocoupler daughterboard for the Duet, so it’s a pretty big extra expense. You can always add this later.

Plated Copper Nozzle

Price inc. vat €11,75

In my world these things aren’t even optional. I know I know, it’s a big extra expense on top of everything else, and sure, you can wait before buying this.. ok it might be prudent to use the included Brass nozzle untill it’s worn down, but this copper nozzle is just so extremely much nice than the standard Brass nozzles.

They were created for ultra high temperature, but lets take this note from E3D:

In addition to high temperature performance these nozzles have an advanced nickel based plating, considerably reducing the adhesion of plastic to the nozzle. This is great for everyday filaments keeping things clean and shiny, but is particularly important at temperatures above 300°C where a silicone sock can’t be used.

And that non-stick feature is what makes it so awesome. If you have printed PETG you’ll cry tears of joy when trying one of these as stringing is just so much easier to manage – also helps on all other materials.

Don’t go and buy the Copper Heater Block as it will really only make your heating up take much longer and suck out €26,4 of your pocket! .

I honestly beleive them to be not at all relevant when using the Silicone Socks on the standard Aluminium blocks, which are included.

Yes, I own one of these and I really don’t much like it. I have not seen any advantages over normal Heater Block. Right now I’ve mounted it on a hotend I use with the TL-Feeder for 2x filament input as it migt be better when hot and cold filament are constantly changed, but I havn’t tested it much yet.

40/80w Heater Cartridge

Price inc VAT €5,4 for 24v 40w
Price inc VAT €6,73 for 24v 80w

What’s this now? Well, the included 30w heater with blue wires is just really slow and in some instances you will find it having problems keeping up the temperature. Especially when printing semi fast.

I strongly recommend buying the 24v 40w instead for this printer and if you tend to print very fast, you might even opt for the powerfull 24v 80w from

Just remember to do a new PID tuning if you change your heater or sensor.

Untill next time!

Wow, that was one long post! Next post is going to be all about the inert parts of the printer.

Posted on 4 Comments

xBot Medium – Look at materials (custom BOM)

In this post I’ll start describing what is needed to actually build the xBot-Medium printer.

I’ve set up a xBot-Medium Github Repository where the files can be found for this project. As I havn’t finished it yet, all the files aren’t there, but they will be! Only the .STP files for the Dibond frame pieces and some a few for printed parts are missing, so it’s pretty much complete allready.

This post is going to be about the custom parts we need for the xBot-Medium 3D Printer. I’ll list the Electronics and Electrical and Mechanical parts in a later post.

xBot Medium materials can be categorized like this:

    1. Parts for Dibond frame
    2. Custom lengths of quality steel rods
    3. Custom metal/steel parts
    4. Custom aluminium parts

1) Parts for Dibond frame

The frame for the xBot Medium is made out of 6 pieces of Dibond pieces. We actually have 8 pieces when counting the Front Door and the Rear Z-Rod Cover, but these two are part of the Top and Front Dibond pieces respectively, as you’ll see here.

Note: Parts might deviate from designs on this page. Always refer to the xBot-Medium Github Repository for the current version


Most items of interested are noted on the piece.

I’ve intended one the two GX16 to the left to be for the Wire harness for the Carriage. The other one for BLTouch or other sensor.

The four GX12 4-pin, two to either side, are meant for Belted Extruder v4.

Above the GX12 holes to the right are cut outs meant for a Titan Extruder or similar, which people can finish on their own if needed.

USB cutout is meant for a Panel Mount USB B Female socket to USB Micro B 5 pin male cable. Ie, giving you USB access to the board from the rear of the printer.


The bottom accomodates a host of cutouts to accomadte our various pieces of machinery and electrical stuff to make our printer.

The mountholes for powersupply is based on Meanwell HPR-450-24 which is a quality 18.8a low profile supply with temperature controlled fans, so it shouldn’t make unduly noise.

Aside from this, you’ll find cutout for 14×3.2cm Chamber heater and mountholes for SSR for the heated bed and of course for our Duet WiFi and Duex expansionboard.

I’ve designed special 3D printable mount parts for the controllers, which incorporates fixpoints for box/shield/fans or similar for the controller.

Lastly we have room for our 3x Z 280mm motors various Z rods and the Optional 3x Z-Max endstops.


The front piece contains the Rear Z-rod Cover and the various mountpoints for the door.

At the lower part there are optional cutouts for a front facing USB for power, but an adapter for the rear USB panel mount could also be mounted here.

We also have room for a manual rocker switch to turn LED on/off.

Finally there are 2 holes for m3 screws placed 80mm apart to facilitate mounting of an LCD panel if you use one.


Left panel contains mount points for the Y-Max endstop and a groove for wires from both the Y and X endstop.

We also have mount holes for our Left Motorshield and holes for the optional front left Z-max endstop.

And of course the motor driving the Y axis.


Right panel is the most simple panel of all.

It contains the mountholes for the optional front right Z-Max limit stop and holes to fix the Right Motor Shield in place as well.


The top piece has the Door inserted into the empty space.

I’ll strongly encourage to have the door made as it greatly improves all prints you make regardless of material. Even PLA benefits a lot from an enclosed room with a steady slightly raised temperature.

Aside from the Door, the Top contains mount holes for the X-Min endstop and holes for both the 2x 12mm Z rods and the 2x 8mm Z rods.

2) Custom lengths of quality steel rods

Next up is our list of 6, 8 and 12mm steel rods.

I know it’s tempting to buy some cheap chinese bundle of “chromed steel rods”, but please don’t. They are most often not straight and the tolerance is also off by default.

My impression: it seems they take normal 8mm steel rods and do a put a “coat” of chrome on it, making it neither precise nor particularily durable. My description on how they do it, might be totally wrong, but it’s the impression I have from many bad purchases for rods.

So, go shop at a place where they guarantee a certain qiality standard, namely h6. It’s a standard for tolerances and deviations allowed and such.

It’s especially important with tight tolerances as we are using bushings for our X and Y rods and sometimes the cheap chinese rods are simply “too fat” for the bushings to pass over.. conversely it’s no good if the rods are too thin either, or not straight.

I’ve allmost always had problems getting the cheap rods through the flanged bearings we use at the XY ends as well.

I’ve ordered all my rods from Dold-Mechatronik this time around and I must say the quality is truely impressive!

The tolerance is 9um (micrometer) which means accuracy within 0.009mm. In other words these rods are high quality steel rods, ground and polished with a superb finish!

# Pieces



 2x X-rods 8mm in diameter. Each of them 367mm long. They run from side to side.


 2x Y-rods 8mm in diameter and 358mm long. They run front to back in both sides


 The two front 8mm rods for Z axis. 339mm long. Runs near each front z motor.


 The two 12mm diameter and 339mm long rear Z-rods. Placed on either side of the center rear Z-motor.


 A single 6mm diameter 327mm long rod running left to right for our Carriage (thing that carries the hotend and fans etc)


 A single 6mm diameter 301mm long rod running from front to back for our carriage.

3) Custom metal/steel parts

Next up is a few pieces we need to have custom made as well. The most important parts are the 4x steel pieces used to keep the four Z rods in place.

The Motorshields are not just for show though, but are intended to partially keep out the heat from the heated chamber while keeping the XY motors cooler using a temperature controlled 40mm fan under each motor. Doing this as the motors performs best and last longer if we can keep their temperature under 40c.

I’ll most likely design some printed versions of these.

# Pieces



Left motorshield. There is room for 48mm long motors making it possible to use quality 0.9 steps Nema 17 motors!
2 m3 threaded holes in each side of the shield for fastening onto the frame in addition to two spuds at the bottom for fastening onto the Bottom frame part.


Right motorshield. There is room for 48mm long motors making it possible to use quality 0.9 steps Nema 17 motors!
2 m3 threaded holes in each side of the shield for fastening onto the frame in addition to two spuds at the bottom for fastening onto the Bottom frame part.


2 pieces of 2mm thick steel plates to hold the 8mm Z-rods in place. There is a m3 threaded hole in each end of the plates to keep them in place.

Note: If you can’t have some made in 2mm steel, then have them made in 4mm thick aluminium. The files for these are located in the xBot-Medium Github Repository


2 pieces of 2mm thick steel plates to hold the 12mm Z-rods in place. There is a m3 threaded hole in each end of the plates to keep them in place.

Note: If you can’t have some made in 2mm steel, then have them made in 4mm thick aluminium. The files for these are located in the xBot-Medium Github Repository

4) Custom aluminium parts

We have 2 custom aluminium parts we need to make for the Z-stage. The Heated bed and the Z-liftplate.

You can use a heated bed from Ultimaker 2 if you choose, but I personally strongly prefer the option with 4-5mm aluminiumplate and an AC under it.

# Pieces



I’m using a PEI-coated 5mm thick aluminium plate from with a 500W AC Keenovo silicone heater under.
I’m recommending using an AC/mains heater, as you remove the stress from your PSU and electronics, meaning it’s easier to cool and you can do with a smaller PSU than you’d otherwise need or run your existing PSU without noisy fans. Note the temperature sensor sits in the middle of the pad and in my experience it shows about 10c more than the actual surface of the bed. At least for a good while.I havn’t shopped at but they have nice prices on their parts and their Ecocast plates would do perfectly for this as well. (choose CAST from dropdown menu.


The Z-liftplate is a bit complicated due to the 3 motors, 4 support rods, 3 holes for screws to hit the Z-end stops and the 3 point Finger Screws to adjust the bed.
I’ve not made cutouts to make it lighter or similar, as it’s mostly for show anyway, but also because the extra cutting takes more time and so costs more money to make.

That’s it untill next time

You can find all the source files in the xBot-Medium Github Repository.
In the next post we will take a look at the Electronics and Electrical and Mechanical parts.

Posted on 15 Comments

xBot Medium – A new printer is baking!

Wow, been quiet for a while, and guess what, I’ve been busy working on completely new printer build, using the best I could find from the Open Source world and added on features I’ve been missing, like true autolevel and front hinged printbed in addition to the back mounted Z-stage on the Ultimaker machines.

  1. Ultimaker as primary source
  2. Design goals and specifications
  3. What can be improved on this package
  4. Dimensions of the xBot Medium next to Ultimaker 2+
    1. Dimensions
    2. Build Volume
    3. Printer and Printing Properties
    4. Materials
    5. Requirments
    6. Print Surface
    7. Controller Type
    8. Motor
    9. Firmware
    10. Powersupply
    11. Chamber
    12. LCD and SD
  5. Compatibility
  6. Fine Touches
  7. What’s next?

Note: Please note that some details has been changed during the design and buildphase. 

Ultimaker as primary inspiration

There, I said it. Ultimaker machines. This means I’ve been inspired by the Ultimaker 2 Open Source panels and did a complete workover to make it all match my needs. In all honesty it looks like a normal Ultimaker frame at first look, but when digging in the main left-over features are the hidden nuts and slot in system by the individual plates. Even those are placed totally different, so it’s only really the concept used. And of course the material used; 6mm Dibond.

Of course; the construction method is one of two things making the Ultimakers what they are, so it would be silly to change these for something else!

Design goals and specifications

The second thing making Ultimakers the best, is how they have, in my opinion, the best XY design of all Open Source printers on the market. They do not risk skewing the axes when changing direction and have build in self-adjustments.

In my optics it’s the best as it’s rock solid, simple to design and setup and requires next to no calibration or maintenance. You can move the printers around all day long, hook it up and print without any adjustments.

I even shipped one of my Ultimaker 2+ machines (clones) across the country. The buyer opened the box, hooked it up and printed right away. No calibration or adjustments needed! Even did the same trick a few weeks later, so yea, they really are rock solid and requires next to no calibration. Except for bed level!

The way the XY is incorporated into the very sleek case with hidden nuts, makes all axes very sturdy, which contributes to the unmatches printing quality of these printers.

During the designface I managed to make room for 48mm deep Nema 17 motors, which meant we can use high quality 0.9 degree steppers (17HM19-2004S) now! Previously we could only get 40mm motors where all 0.9 degree motors (I have ever seen) has very high Inductance mH, which really must be under 4mH to get acceptable performances.

All in all it just makes for an incredible appetizing package with both functionality and visual design at the fore.

What can be improved on this package?

There’s not much to change on the physical level, but the Z axis has always been the achilleius heel of the Ultimaker printers. It’s only fixed at the rear side and while the the Z rods has moved up in size from 8mm to 12mm, which improved a lot, the stability is just not as good as it could be.

I’ve previously fixed the Lead-screw at the top, which helped stabilize the Z some, but the leadscrew is not meant for this kind of usage. Especially bad if using a poor quality lead-screw which isn’t all straight.

I also created a method of using an Anti-backlash nut. Later on in the UM2+ and UM3 machines something similar appeared in the form of the T8*8 Delrim nut.

The Brass version of Anti-Backlash nut has become very cheap and more popular as it’s a drop in replacement to the normal Brass nut.

I’m a big fan of these Brass Anti-backlash nuts as they are cheap, drop in replacements and they compensate for both bad quality you might have in your lead-screws (and backlash nuts) and for the wear the nuts especially are going to be subjected to over time. Using regular nuts the gaps between the ridges steadily increase with wear and tear, leading to inaccuracies, especially when using z-hop, but the spring compensates for this kind of wearing down.

I’ll be using 3 of these Brass Anti-backlash nuts for the xBot Medium

To truly overcome this challenge I wanted to add 2 extra Z motors with additional z rods at each front corner, for a total of 3 Z-motors and 4 Z-rods, to make it more stable and also to build in the option for true auto-level function.

All without making the machine huge and bulky!

Some challenge, uhh?

Dimensions of the xBot Medium next to Ultimaker 2+

Note/Disclaimer: All info and images of/about the Ultimaker is from Ultimaker 2+ specificatiosn page and the Printer Comparison Page. They belong to Ultimaker and all credits goes to them. I am in no way affiliated with Ultimaker and I solely show the info here to show where I came from.

I have tried making the below table to illustrate and explain the changes and differences between the super nice Ultimaker 2+ and the xBot Medium I’m building.


Ultimaker 2+

xBot Medium


Dimensions with bowden tube
and spool holder:
34,2cm (width) x 49,3cm (depth) x 58,8 cm (height)
(13.5 x 19.4 x 23.1 inches)
11.3 kg (399 ounces)

Dimensions with extruder, bowden tube and spool holder
36,8cm (width) x 50,3cm (depth) x 42,8cm (height with 1,75mm)
Note: Height is up to 20cm more if using 3mm filament

Build Volume

223 x 223 x 205 mm
(8.8 x 8.8 x 8.1 inches)

223 x 223 x 205 mm
(8.8 x 8.8 x 8.1 inches)

Printer and Printing Properties

1x 2.85mm Geared Feeder

Open filament system

180 °C to 260 °C
Olsson’s Block
Up to 4x Belted Extruders v4 and 1x Titan or similar in any combination of 1.75 and 2.85mm

Open filament system

180 °C to 500 °C

E3Dv6 Full-MetalHeated Chamber


PLA, ABS, CPE, CPE+, PC, Nylon, TPU 95A, and PP  PLA, ABS, CPE, CPE+, PC, Nylon, TPU 95A, PP and Breakaway (all materials)


Ultimaker Cura or other Slizer

File transfer: Standalone 3D printing from SD card (included) or USB

Ultimaker Cura or other Slizer

File Transfer: WiFi drag and drop for standalone 3D printing.

Optional printing from SD card if the optional PanelDue is in use.

Print Surface

Heated Bed: 100w (24v 5a) 2mm aluminium heater.

Print Surface: 4mm Borosilicat/Tempered Glass. Optional Fiberplate FlexiPlate etc

Guided leveling of buildplate

Heated Bed: 500w (240hz AC (Mains) via SSR) Silicone Keenovo heater under 5mm milled Aluminium plate.

Print Surface: PEI-Coated Aluminium plate. Optional 4mm Borosilicate glass or Fiber plate etc.

You can use Ultimaker 2 heated bed if you so choose. Same mountpoints.

Full true automatic autolevel.

Controller type

Ulticontroller – 8bit

5x a4988 drivers and 3x PT100 amplifiers.

Controller Duet WiFi – 32 bit

5x TMC2660 drivers.

Thermocoupler Daughterboard for 2 Thermocouplers.

Using Duex2 or Duex5 for full use of autolevel and multiple extruders.


1.8 degree motors for XY.
Single linear motor for Z
1x 0.9 degree motor for Extruder
High quality 0.9 degree motors (17HM19-2004S) for XY from
3x linear motors for Z for true autolevel function
1-5x motors for extruders.
For 1.75mm filament: 17HM08-1204S
For 2,85/3mm filament: 17HM19-2004S


 External Meanwell 24v 15.8 (black brick type) Internal Meanwell 25v 18.9a with temperature controlled cooling.


 Ultigcode/Marlin firmware  RepRapFirmware


 External Meanwell 24v 15.8 (black brick type) Internal Meanwell 25v 18.9a with temperature controlled cooling.


100w Temperature controlled Heated Chamber
Door in Dibond with acrylic window

LCD and SD

 Small LCD control panel with SD card  Optional PanelDue color touch display with SD card.
options: 4,3″, 5″ or 7″


To the best of my abilities I’ve kept it as close to the Ultimaker 2 as I could. This means most things can be directly reused, if you have build a previous UM2 clone, like belts, pulleys, heated bed, finger screws, screws/nuts , XY endstops, all the bearings and the thick 12mm Z rods.

Also using same Z motors, although the xBot is using 3 of those.

You can even reuse your extruder if you have a Titan or UM2 extruder, allthough I do recommend using my Belted Extruder v4 as it’s way more quiet and performance just as well.

Fine Touches

In the back plate there are holes if you want to use an extruder as in the normal Ultimaker machines. I havn’t sunk the holes all the way through for Titan extruder, but they are marked up on the files, so it’s easy to remidy it.

Same goes for the various Optional settings in other plates like front USB plug, manual LED on/off switch and the two optional mount holes for PanelDue, if you choose to use one.

Instead of full wire draws I’ve opted to use the Aviation plugs in sizes GX16 for the wireharness up to the Carriage for Heater Cartridge, Temperature sensor, heatsink fan and printed object fans. A second GX16 for the BLTouch or some other sensor as well.

I’ve used 4x GX12 4pin Aviation plugs for the 4x top mounted Extruders on the rear side, and also a single GX12 4pin connector, installed in the bottom part of the frame, next to the Chamber heater vent, for the 4 wires up to the heated bed.

Here are 2 photos from a different machine to illustrate how the GX12 plugs will be placed on the rear side. All the wires going through on the photos here, will be replaced with the larger GX16 Aviation connectors.

What’s next?

I have ordered linear motors and parts from Robotdigg, quality steel rods from Dold Mechatronic and have put in an order for the Dibond plates here in Denmark with a private person, so can’t link to him… so now it’s just waiting time for me over Christmas.

The X and Y motors are high quality 0.9 degree motors (17HM19-2004S) from OMC-Stepperonline which can fit in there due to room for 48mm motors compared to Ultimaker’s room for 40mm motors only.

.. or.. Actually I’m busy working on creating documentation for a Github page for this project where alle the relevant files will be publicly available.

I have in fact allready created a Repository for the xBot Medium on Github and started putting various files and info in it, so please stay tuned.

The STEP files for the side panels will not be made publicly available untill I’ve tested them.

Stay tuned, here, maybe on my Facebook channel and on the Github repository as well 🙂

Merry Christmas to everyone 🙂


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Duet WiFi – Activate and connect the WiFi… when it doesn’t work!

Guess we’ve all tried it.. just can’t get the WiFi to connect to our home network. Especially after a firmware upgrade.

For some reason the non-macro manual method doesn’t always work, and I’ve learned that the most simple solution then, is to create a macro file with the needed info and execute the macro.

This post is a boiled down version of my Duet WiFi/Eth – Recover from Erase + basic setup post.

Macrofile for networksetup

  • We need to create a small macrofile to make it connect to our WiFi.
    I tried doing this manually without the Macro, but I simply just could not get it to connect..
  • So, go to your Macros folder on your SD card and create a new file named SetNetwork containing the following commands (without spaces before or after the commands on each line):
    M552 S0
    G4 P1000
    M587 S"your-network-ssid" P"your-network-password"

    Source info
  • Now eject the card from your computer and insert it into your Duet WiFi and connect it to your computer using the USB cable

Activate WiFi

  • Connect to your Duet WiFi using Pronterface YAT and type M552 S0 to start the WiFi module
    M552 S0
    SENDING:M552 S0
    WiFi module started
  • Type in M98 P/macros/SetNetwork to execute the macro we created
    >>> M98 P/macros/SetNetwork
    WiFi module started
  • Send M587 and check that your network is listed
  • Send M552 S1.
    After a few seconds you should see a message that it has connected to your access point and display the IP it has recieved.
  • Connect via the web interface
  • Enable the M552 S1 command in config.g – if it’s not in there, then just make a new line and type it in.
  • For security reasons you might want to delete the SetNetwork macro file

SD Card Folder Structure

It’s usefull to know how the structure is supposed to be on the SD-card and also to know the function of each of the files and more info.

All this is shown on the SD Card folder structure wiki page