RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Dobbewan, that sounds very promising. Could I have you do a retraction test print for us? The attached 3mf is a simple rectangular prism.
Print setting should be set up to slice as two perimeters, no infill, no top layers. Basically, it must print hollow with two perimeters, definitely NOT in vase mode. This force rectangle to it will have a seam at which the printer will do a retraction and restart for both inner and outer layers. I noticed early in my 0.9 pancake testing that examination of the seam, especially the inside layer would reliably show gaps at the restart with 0.9 pancakes. From the outside, a failing restart looks like an odd distortion at the seam. Under transillumination, a failing restart looks thin at the seam.
If your LA 1.5 firmware and 0.9 pancake can print this with perfect restarts at the inside layer, it would be objective evidence that the LA 1.5 is achieving the result intended.
Thanks for forging forward for us all.
Attachment removed
I sure can! I will post other photos shortly. Doing a fun test print I want to show off if it finishes. But no more violent retractions with extruder clicking!! All of my prints will be on prusa stock grey pla
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I couldn't be happier right now. Everything is coming out flawless. I thought I was going to have to swap back to my moons 1.8 to get rid of those nasty retractions!
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Wow those pictures look like poo uploaded on here... This is the folder for all of my test print pictures so far https://drive.google.com/drive/folders/1mJ34L8zvY2P5WYPuSqCVz23vbvd_2f-Y?usp=sharing
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Exterior looks good. Are the interior seams complete (no gaps in extrusion)?
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I think I have a good guess of why the printers are sometimes not accepting new microstep values for extruder motor. The printer overrides firmware numbers if it finds a previously stored value in EEPROM. Factor reset with deletion gets rid of the old, stored value and lets the firmware's values take effect. That could be why e-steps are sometimes stuck at 32 despite my new firmware specifically setting it to 16.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
No gaps that I can see at all! Some little gaps on the ghoul that I printed, but that may be due to slicer settings or the fact that I was running it at breakneck speed to see if it would keep up!
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
No gaps! That is great news. We'll probably adjust things on my 0.9 firmware to where we can hopefully get GIThub to automate the merge. Won't be right away though. Lots of things in the queue
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I think I have a good guess of why the printers are sometimes not accepting new microstep values for extruder motor. The printer overrides firmware numbers if it finds a previously stored value in EEPROM. Factor reset with deletion gets rid of the old, stored value and lets the firmware's values take effect. That could be why e-steps are sometimes stuck at 32 despite my new firmware specifically setting it to 16.
I wonder if there is a way to zero out that value using a firmware upgrade or special gcode.
(Exposing my considerable ignorance.)
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
hiya guys i've been following this thread for a while and it looks awesome. just discovering these moons motors and what is it like new drivers? i'm quite overwhelmed with everything thats happened, so like - is it possible to get a summary for dummies? apologies if this has already been asked.
im roughly aware of this VFA phenomenon
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
@guy-k2 I think I'm very close to where I want to be. I do still have the larger artifacts, plus minus 2mm apart. I have changed the idlers to the wider ones and the pulleys I'm using are the original smooth ones (getting better results than toothed ilders).
Would you say belt tightness is next? I'm thinking to loosen them more.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Hello, I thought that i will share my results of swapping Y motor to Trinamic motor QSH4218-51-10-049. This is the only change i made to a completely stock MK3S, so there are still some ghosting and other effects at play. But i feel the result is really good and no firmware shenanigans needed :). I think a geared extruder will be the next step ;).
Edit: The media player for video did not work
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I decided to try out the firmware including LA15. The only thing I noticed is that the homing reset distance (not sure the proper name - the move in the positive direction before the second endstop hit) is a bit longer in this firmware.
I'd say the results seem pretty good so far. I printed Guy's retraction test object. The corner I'm showing IS the retraction corner and I literally can't find a seam on the inside or outside.
I also ran a couple cube's before the firmware change and after. Left is LA15 version, right is Guy's firmware. The only real difference is that you can see some slight retraction restart issues on the Z size at the ends of a couple top layer fill lines (bottom left cube face and bottom left of top stroke on the Z). The ghosting was the present on both prints, but hard to photograph and get the right bounce to show the VFAs. But these are both damn near perfect.
And my fun print for the day, at my daughter's request:
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I think I got GitHub to merge the Prusa MK3LA15 into a separate branch of my firmware. First attempt from another fork was a total disaster requiring complete deletion and restoration of my fork.
https://github.com/guykuo/Prusa-Firmware/tree/LA15-and-0.9-Degree-Stepper-Support
I can't test on my own machines because they are busy on long print jobs.
(Actually, ahead of LA15 in the queue is testing of a pair of new tungsten carbide nozzles on the Mosquito)
Those Trinamic motor results look great. Really shows how non-uniform the stock motors perform. Going to 0.9 motors was one way to get a more linear motor. Would be interesting to head to head test 0.9 Moons vs Trinamic 1.8 motor. Those non-detente motors are also looking useful.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
...
Would be interesting to head to head test 0.9 Moons vs Trinamic 1.8 motor. Those non-detente motors are also looking useful.
Test prints started. 😉
Besides XYZ cubes, are there any other prints you'd like to see?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I have seen the effect amplified in the Prusa pre-sliced 3DBenchy that came on the SD card: one side will have nasty lines in it that you can see easily and feel with a fingernail. Some round prints have also had regions of amplified lines with the original motors. After i changed y and x motor to trinamic 1.8 motors at least the 3DBenchy improved a lot.
So maybe the 3DBenchy and/or something cylindrical besides the cubes.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Here are a pair of 20mm XYZ calibration cubes. To ensure the same spectral effect, light balance, and focus, I photographed them at the same time. I'm no expert photographer, so feel free to request something different if you're looking for something particular.
For all photos:
Top = 1.8° Trinamic QSH4218-51-10-049
Bottom = 0.9° Moons MS17HA2P4100
X with Flashlight
Y with Flashlight
Y Opposite Face
X with No Flashlight
Other modifications:
- BNBSX Extruder with 1.8° Moons MS17HD5P4070
- Slice Mosquito Hotend
- Misumi linear bearings and rods
- Misumi 16T pulleys
- Gates 20T 5mm idlers (Y Mount, X Mount)
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
...and now for some 3dBenchies:
Starboard Side, TMC QSH4218-51-10-049:
Starboard Side, Moons MS17HA2P4100:
Starboard Front Quarter, TMC QSH4218-51-10-049:
Starboard Front Quarter, Moons MS17HA2P4100:
Posted without commentary, because I don't want to influence anyone's opinions. I'm curious what other people think besides myself!
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
THANKS Evan! Really nice set of comparison prints and photos. Much appreciated. I will also withhold comment.
Now we need one of the detenteless motors.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
You're welcome! And right back at you, for all your hard work paving the way.
And yeah, those zero-detent motors look wicked. I was tempted, but I've already got a pretty big pile of steppers sitting here unused...
At this point, I've personally moved from looking at hardware for improvement to the software side. The above Benchies were all printed with the GCode that came with the printer. At this point, I feel like slicing is the next weak link in the chain. The best results I've achieved since then have come from focusing on slicing or other software parameters.
The best I've been able to do (while retaining 0.15mm layers and 2-ish hour print times) is this, in Prusament Galaxy Black PLA:
Still suffering from the well-known solid-layer problem, but otherwise, the surface looks good and feels smooth to the touch. 😀
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I am contacting Lin Engineering to see how I can obtain a Zen stepper. Not exactly an item we can find on Amazon.
Yeah that solid layer bulge is an ugly thing.
My next niggle is uniformity of layers. There is a small difference between layers that seem to affect nearly entire layers at a time. I don't know if it is z-stepper uniformity or filament diameter changing in spool.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Because EEPROM will override settings in my firmware for microstepping, we have needed to do a full factory reset with delete.
I think that is still the best course, but a quicker way of manually forcing microstepping is possible via M350. There are four possible settings, you have to do the one that matches your setup. Right after your M92 Exxx for setting e-steps.
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non-geared extruder, 1.8 degree motor
M350 E32
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non-geared extruder, 0.9 degree motor
M350 E16
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geared extruder, 1.8 degree motor
M350 E16
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geared extruder, 0.9 degree motor
M350 E8
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follow with M500 to store to EEPROM
power off/on
check with M503 to verify settings.