I'm pleased to share a personal project of mine, where the initial design started in late 2018, and purchasing starting in March of 2019. By no means is this complete, but I'm at a point where I'm pleased with the progress I have made so far.

Some background - My first real experience with 3D printing was in 2017 at the office; we had a Stratasys Dimension 1200es BST that wasn’t getting much use. I started printing practically anything I could think of, starting with a small hand tool, and progressing to much larger and more sophisticated designs. In early 2018 I got the go-ahead to propose a new 3D printer model that we would buy two of – because more is better, right? At that point I realized both the age of the Stratasys machine, as well as the wealth of hardware and software options for printers available at the time.

We opted to go with two BCN3D Sigmax printers – dual extrusion was a must, the IDEX technology had some potential uses, and the large bed width had advantages. I spent quite a bit of time learning how to effectively operate those machines; later I picked up a used Davinci 1.0 and flashed it with Repetier, built a MPCNC, and eventually the Stratasys went belly-up and made its way home with me.

My initial design objectives were to have a machine that…

• Has a rigid frame
• Has a limited number of 3D printed components
• Has an enclosed and heated chamber
• Has a large print area
• Is capable of printing high temperature thermoplastics
• Is capable of dual extrusion
• Is capable of fast travel speeds with reasonable accelerations

To start the design, I purchased two Rexroth ballscrews and 3x sets of IKO LWL12B 500mm rails with two ML12 each, sizing the frame to these components. Later on I purchased two LWHT15 200mm rails with a single carriage each for use with the ballscrews for the Z-Axis.

Other design and component decisions:
I wanted to utilize the Gates GT3 series of belts and compatible pulleys

• For the Y-axis I selected 3mm belt pitch, 15mm belt width
• For the X/U-axis, I selected 2mm belt pitch, 9mm belt width

I wanted to balance speed and resolution

• 16x microstepping, manger to achieve 100steps/mm in the X/U axis, 96steps/mm in the Y axis
• Y axis is geared down with a 2.25:1 gear ratio to compensate for the heavier axis
• X, U, and Y axis run at 300mm/s max speeds and 4000mm/s^2 acceleration

For the Y-axis and Z-axis, stepper motors are NEMA 23

• Oriental Motor PKP264D28AA2, .74 N*m, 2.8 A/phase, 1.5mH/phase
• Set to 2.4A in config.g
• Run super cool, barely feel warm to the touch

X and U axis use NEMA 17

• Oriental Motor PKP244D23A2, .48N*m, 2.3 A/phase, 1.9mH/phase
• Set to 1.8A in config.g
• These run quite a bit warmer than the NEMA 23s

Slice Engineering Mosquito and Mosquito Magnum for hotends

• Various nozzles (P3D, E3D NozzleX, Slice Vanadium
• Slice thermistors and heaters
• 12V Sunon fans

5/16” ATP 5 plate, 1000W Keenovo heater, SDF DF240S thermal cutoff (200°C holding temperature)

• TCO holding temperature may be a little high, but Keenovo recommended a maximum operating temperature of 204°C based on the 3M adhesive rating.
• Three-point bed leveling with probing
• Initially looked at a kinematic bed solution but opted for a fixed countersunk screw/spring combo, with two slotted countersinks sized and positions to account for thermal expansion.

Bondtech BMG-M extruders

IDEX

• I do enjoy the IDEX technology on the BCN3D printers but wanted something a bit more structurally sound. Lots of inspiration taken from the Stratasys Dimension 1200es.

Duet controller board(s) - Duet 2 Wifi, Duex5, PanelDue 7i

Snap action homing switches for X, U, and Y

• These have moved quite a bit as the design has evolved, I’m not happy with how they are mounted at the moment
• Had a homing “oopsie” where the U assembly crashed into the X carriage, actually moving the switch mounting block, and messing up my calibration!

Right now I’m looking at a print volume (single extruder) of 420mm x 450mm (475mm Y travel) x 210mm, losing ~100mm (to ~320mm) on the X and U axis for dual extrusion (lesson learned there!).

The project so far has been a blast, with many lessons learned along the way. The X-U axis has by far been the most challenging to build and design, I’m on the second major iteration and I’m still not entirely pleased, although I am getting satisfactory print results. As this is my first printer design and build, it was challenging to prioritize assembly design priorities. With this project, despite having a good idea of the components I wanted on each hotend assembly, it was the last item I designed and built up – ends up my build plate was a bit too big, leaving me little room to have nozzle wipe stations, purge buckets, etc. On future projects I for sure have a better idea of what assemblies to prioritize, making further decisions based on the size and function of said assemblies.

While working on this project, I did not initially intend to share the design files, however because of all that I learned from the fantastic content and individuals on this community and others, I figured I should give back and contribute this project.

https://drive.google.com/drive/folders/12TOxGG-kKjuYwNuwhYpwor9TGhdfy2mg?usp=sharing

The Google Drive link contains a Solidworks (19-20) pack-and-go, as well as assembly parasolids (.x_t) and IGS files. A (very!) rough BOM and various images and videos of my progress are also available.

How have I done so far?

• Has a rigid frame - definitely nailed this one! Almost entirely end tapped extrusions with fasteners + access hole
• Has a limited number of 3D printed components - making progress, but not quite done. Y axis bearing holders, most of the hotend carriage assembly is still 3D printed
• Has an enclosed and heated chamber - making progress on enclosure, have not installed+tested active chamber heating (excluding built plate)
• Has a large print area - pretty satisfied
• Is capable of printing high temperature thermoplastics - goes hand in hand with the heated enclosure, no issue with extruding 9085 PEI, but I have not tested an actual PEI print (the volume above the build plate stabilizing at 50°C without being fully enclosed, which is pretty neat, but not enough for PEI)
• Is capable of dual extrusion - accomplished
• Is capable of fast travel speeds with reasonable accelerations - accomplished

Many thanks to Slice Engineering, PrintedSolid, and Filastruder ( @elmoret ) for fast shipping, excellent communication, and great customer service when it was needed, as well as to the Duet team for a fantastic product.

@Corexy said in Mesh Compensation:

I'd just like to run the mesh occasionally via the "calibration and compensation" tab in the DWC, and have every print just use the latest mesh.

Problem is that it doesn't seem to store the mesh after being shut down, as if I start a new print and open "calibration and compensation", it says there's no mesh compensation in play.

I really just want to do the G29 if there's some sign of first layer issues, rather than at the start of each print.

How can I store the last mesh, and make each future print use it?

I have G29 S1 at the end of both my homez.g and homeall.g. When I first power the machine on it says no compensation is in use, however if I were to start a print (start gcode calls for a homeall/homez) or press the home z or homeall buttons, the compensation file is loaded once complete.

@droftarts said in U axis don't print:

@sebkritikel @noisettetbou @Danal Thanks for your work on this thread! I really didn't have much of a clue where to start with IDEX. If you have any comments to update the IDEX page in the wiki here , or specifically this section , can you let me know and I'll update it?

Actually, looking at the IDEX wiki page, most of the info seems to be there?! Perhaps just a bit about the X parameter mapping using the order XYZUVWABC, where X=0, Y=1, Z=2, U=3 etc?

Ian

I would agree that most of the info is there, but adding additional clarification on the X parameter mapping would be great, as well as a small section on M579 for mirror printing in the area discussing tool generation. Thanks!

A reminder that the actual torque a stepper motor would provide for a 3D printer is Torque * .71 * .098, with 71% coming from the torque drop when using microstepping and 9.8% coming from reducing motion lag to be less than 1/16th a microstep during acceleration. Add in another loss from multiplying by 85% if you aren't running your stepper motors at full current.

The NEMA23s I have provide .74Ncm at 2.8amps, but including the losses, .74Ncm * .85 * .71 * .098 = 4.4Ncm (6.23 oz*in). I then gear that down so I can get ~4000m/s^2 acceleration on my IDEX gantry (depending on how I calculate the mass ), with the gearing providing ~8.3N in the direction of travel.

Have not used a MarkForged machine, but I believe Stratasys has a similar system used with their Dimension (and would assume uPrint) line of printers. During a print (specifically with model material and support material) the machine can detect a layer shift (or more specifically any unexpected print head movement) during the material/nozzle switch. The print head travels to one end of the Y axis to toggle the nozzle switch mechanism, where there is also an optical endstop. If it detects a shift, it kills the print and throws an error.

@HC3D said in Printer pausing 1-3 sec every ~10 print moves:

Now with Cura, the problem turns out to still be there.

@jay_s_uk @whosrdaddy, OK, I performed your suggested changes. The problem is still there, but I will keep those new values.
@droftarts I am printing by transferring the files using DWC first. I noticed my G-code file is fairly large, for example 11MB for a 45-minute print. Your hypothesis that the system is not able to handle the command rate is a possibility
@dc43 In cura, I am using a retraction speeds of 50mm/s, so retraction must not be causing issues now.

Perhaps the 11MB GCODE file is too dense for my system to process? My CAD tool cranks out a fairly high number of polygons; my STL output setting is fairly high.

Here is a video when printing a Cura-generated file: https://youtu.be/W3kOFaIqv9E
Here is the G-code file: https://www.mediafire.com/file/yua9zzaew00neom/CFFFP_Part1.gcode/file
Here is the STL file: https://www.mediafire.com/file/2fy9i8nwts74eba/Part1.STL/file

Any ideas as to what could be going on?

Took a quick look at the GCODE you posted, can you verify if you mean to set the GCODE flavor to Marlin in Cura?
;FLAVOR:Marlin
If not, you can change it to RepRap under "Machine Settings"

@droftarts said in U axis don't print:

@sebkritikel @noisettetbou @Danal Thanks for your work on this thread! I really didn't have much of a clue where to start with IDEX. If you have any comments to update the IDEX page in the wiki here , or specifically this section , can you let me know and I'll update it?

Actually, looking at the IDEX wiki page, most of the info seems to be there?! Perhaps just a bit about the X parameter mapping using the order XYZUVWABC, where X=0, Y=1, Z=2, U=3 etc?

Ian

I would agree that most of the info is there, but adding additional clarification on the X parameter mapping would be great, as well as a small section on M579 for mirror printing in the area discussing tool generation. Thanks!

@noisettetbou said in U axis don't print:

@sebkritikel
It works ! Thanks a lot. It's strange I need to map the driver 5 with the number 3 but the essential is that it works.
For mirror, I've put the M579 U-1 in tpost3.g and M579 U1 in tfree3.g for return to normal direction when T3 is unloaded.
Thanks again.

Nice, glad to help! Good idea on M579 in tpost3.g and tfree3.g!

To understand why it is X3 instead of X5, reread M584 https://duet3d.dozuki.com/Wiki/Gcode#Section_M584_Set_drive_mapping
3 or 5 does not mean driver, it means axis. The axis value is from XYZUVWABC, with X starting at '0'

@Danal said in U axis don't print:

OK, I think I've got it. Try this:

M584 X0 Y1:2 U5 Z6:7:8:9 E3:4 ; Mapping drivers

M563 P0 D0 H1           F1    S"X" ; define tool X
M563 P1 D1 H2     X3    F4    S"U" ; define tool U
M563 P2 D0:1 H1:2 X0:3  F1:4  S"XU" ; define tool X+U copy mode
M563 P3 D0:1 H1:2 X0:3  F1:4  S"XU" ; define tool X+U mirror mode

The "3" seems to be the logical number of the axis to be mapped. That is X=0,Y=1, Z=2,U=3, etc. And the lines that map the copy or mirro do seem to need both the 'base' axis and the 'extra' axis.

Let me know if this works.

I'm running an IDEX machine (albeit on RRF2) but this should do the trick.

X3 instead of X5 is correct - X (0), Y (1), Z (2), U(3)

I have not tried mirror mode. The documentation refers to M579 (Scale Cartesian axes), however where would the best place for that be? In the start GCODE of a print file? "M579 U-1" is needed to "scale" the U axis in the negative direction.

With that GCODE test we definitely have a lot going on.

Regarding the filament extrusion running backwards - It is my understanding (from what I have read here) that based on your (generic your, not saying specifically your system) system, it is perfectly acceptable to have the extruders running backwards during certain moves based on PA settings. However, 100mm is not normal, and I do NOT believe that is related to (or more specifically, DIRECTLY caused by) pressure advance. In my experience with BCN3D Sigmax machines, with bowden tubes of 865mm, a jam (or flow restriction) in the nozzle results in a high pitched squeal from the extruders, with the filament jumping backwards by a significant amount. The dual drive extruders on these machines are capable of compressing the fillament and stretching the tubes during a clog/jam, and when this back pressure is able to overcome the extruder motor. Based on your print temperatures (215°c or so right) I could definitely see jamming or clogging happening, but I'm sure you've looked at this.

Still a lot more to unpack but to be honest, I feel like its working as intended, that high value of PA should sound like gunshots going off (especially with NEMA23s). I'm far from an expert though!

Does this quick video (your EccentricGearTest 0 0.gcode file) represent the issues you face while printing (including the movement of the print head)?
https://www.youtube.com/watch?v=J-_RAQJW1kk&feature=youtu.be

I incorporated these lines into the GCODE file in an attempt to emulate your setup.
M207 S3 R0.0125 F20000 Z0.5 ;firmware retraction
M572 D0 S0.5 ; pressure advance (S) in seconds

@Corexy said in Mesh Compensation:

I'd just like to run the mesh occasionally via the "calibration and compensation" tab in the DWC, and have every print just use the latest mesh.

Problem is that it doesn't seem to store the mesh after being shut down, as if I start a new print and open "calibration and compensation", it says there's no mesh compensation in play.

I really just want to do the G29 if there's some sign of first layer issues, rather than at the start of each print.

How can I store the last mesh, and make each future print use it?

I have G29 S1 at the end of both my homez.g and homeall.g. When I first power the machine on it says no compensation is in use, however if I were to start a print (start gcode calls for a homeall/homez) or press the home z or homeall buttons, the compensation file is loaded once complete.

@dc42 said in New Large Format IDEX Printer Project:

Thanks for sharing! Let us know how well it works.

While I still have a few issues to work out, I'm quite happy with how it runs. This is my first experience with the Duet line of products, and I was blown away with how easy initial setup was - definitely ruins other firmware and controller boards for me!

A large PA6-GF30 print I did recently (model on the left, removed support on the right)