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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

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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.

Sliders

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.

 

LM6LUU

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.

Spacers

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.

Specifics:

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 liutaioMottola.com

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.

Fingerscrews

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)

Motors

  • Z-Motors
    • 12x m3 10mm Button Head Screws
  • XY Motors
    • 8x m3 30mm Button Head Screws
    • 8x m3 Metal Spacer
Motorshields
  • 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
      or
    • 6x m2.5 12mm Screws
    • 6x m2.5 nuts
  • X and Y Limit Switches
    • 4x m3 10mm Button Head Screws
      or
    • 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

Connectors

  • 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

SSR

  • 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.

Quality
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.

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.

Remote
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.

Features

From the official Duet3D Features page.

Feature list
From Duet3d.com 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 🙂

Duex5

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.

BLTouch SMART

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 clever3d.de 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.

SSR

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 OMC-Stepperonline.com 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 OMC-Stepperonline.com.

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

Extruder(motors)

Price for 17HM08-1204S from OMC-Stepperonline.com (48mm long) €11,9
Price for 17HM08-1204S from OMC-Stepperonline.com (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 / 15,6oz.in / 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 Amazon.de, 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%.

Powersupply

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

LED – RGB

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.

Various

 

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)
 

Carriage

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.

Hotend

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.

Thermocoupler

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 RepRap.me

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

Back

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.

 Bottom

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.

Front

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

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

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.

Top

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

Drawings

 x2

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

x2

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

 x2

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

x2

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

 x1

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

 x1

 
 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

Drawing

x1

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.

x1

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.

x2

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

x2

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

Drawing

#1

I’m using a PEI-coated 5mm thick aluminium plate from clever3d.de 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 Aluminiumwarehouse.co.uk but they have nice prices on their parts and their Ecocast plates would do perfectly for this as well. (choose CAST from dropdown menu.

#1

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.

Specifications

Ultimaker 2+

xBot Medium

Dimensions

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)
Weight:
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


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

Dimensions:
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

Materials

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

Requirments

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.

Motors

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 OMC-Stepperonline.com
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

Powersupply:

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

Firmware

 Ultigcode/Marlin firmware  RepRapFirmware

Powersupply:

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

Chamber

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″

Compatibility

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 🙂