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
- Duet WiFi
- PanelDue 5″
- BLTouch SMART
- Heated Bed
- 3x Z-Motors
- XY Motors
- Chamber Heater
- 2x 30mm fans for Printed objects
- LED – RGB
- Untill next time
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.
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
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.
- 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.
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.
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
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
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.
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)
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
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
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!
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.
- Full Datasheet: 17HM08-1204S.pdf
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
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:
- The 24v power line connects to red wire on one fan
- Gnd to the black wire on the other fan.
- The unused pin from each fan is connected by a wire or similar.
- 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%.
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.
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.
- Dimensions: Width 105mm, height 41mm, depth 218mm
- Datasheet opens pdf
LED – RGB
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
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
We need 2x Limit Switches with long arms for our X and Y axes.
Limit switches – short arm
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
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
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
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
- 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.
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.
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
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
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.