RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Great to hear. Bunnies approve.
One thing I had to change though for the BMG is the Z height - dropped it to 205.
Oh....yeah. Forgot about that. It used to be done automatically with the BMG define, but had to remove the statements when GitHub had trouble automatically merging 3.7.1 with that portion of my code in bool calibrate_z_auto(). Have to go back and add that back in.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I found the GitHub instructions and plan to follow along... firmware is new for me. I am buying the OMC because, $, and I plan on duplicating the setup on a second machine, maybe a third. (Sadly I am also considering buying a Method or Form 3 to get past this and make better parts.)
My main question is... Are there other things to be done to quiet the fine artifacts, besides upgrading the motors? Dampened motor mounts, shaft couplers, even a tpu O-ring between Frame and motor mounts or belt mount to frame isolation? IE... Is there some part design that I can do to help improve the situation?
I have Misumi bearings, and I have designed and built and shared frame stiffening with the power supply bracket, integrated YZ frame with Einsy case, isolated vibration of the Z spline, Active Cooling support for the 2130's and made a few other changes that reduce the VFA in X to zero and I still have VFA in Y, small but enough to ignore but still I want to pursue refining via motor swap.
I have cut calibration cubes at 40mm.
https://www.dropbox.com/sh/eejj4qb96ygxpka/AADtFRDxGhdgG0JjbE7QnDDYa?dl=0
Regards,
Carter
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
There is a MOONS MS17HD6P4200 STEPPER MOTOR, HIGH TORQUE, 2 PHASE NEMA17 - DAMAGED on eBay for about $30
What is the P4200 vs P4100 issue?
C
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
My main question is... Are there other things to be done to quiet the fine artifacts, besides upgrading the motors? Dampened motor mounts, shaft couplers, even a tpu O-ring between Frame and motor mounts or belt mount to frame isolation? IE... Is there some part design that I can do to help improve the situation?
I spent many hours also testing vibration damping the motors. Isolation mounts, neoprene gaskets, vibration damping pads, harder vs softer feet.... Things with the motor mounting mostly made no discernible difference or (more often) things slightly worse. Reducing frame vibration with soft feet and stiffening the front and back plates did help a little bit. Getting the motors RIGIDLY attached to frame was slightly helpful.
All those maneuvers took a long time to test and at most made a tiny difference - maybe 10-15% change in surface defects at most.
On the other hand, changing x and y to 0.9 degree motors was TRANSFORMATIVE, massive, obvious improvement far exceeding what weeks of other tweaking accomplished.
Yes, you can try those other things, but in my testing on the MK3, most are barely effective or worse, counterproductive.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
There is a MOONS MS17HD6P4200 STEPPER MOTOR, HIGH TORQUE, 2 PHASE NEMA17 - DAMAGED on eBay for about $30
A bad Moons' is worse than doing nothing.
Just get the OMC's if budgeting is the issue. If super tight, do just the Y-axis. That is the worst offender.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
MS17HA2P4100
Bought Moons direct, free shipping... $41.30 ea
Thanks for the Github page!
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
So I am just about to try installing the .9 moons motors on X and Y. I tried the 1.8 moons not to have to deal with custom firmware, but didn’t get the improvement I wanted.
I also have the Bondtech. Will following your instructions for building the firmware uncommenting X, Y, and BMG work? Or do I have to set the height somewhere now too.
thanks so much for all your work on this!!
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Yes, uncomment X and Y
comment E
Uncomment BMG
Still have to set height elsewhere. I have not had chance to go back and add that back in. There is some new code I don't understand yet.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Yes, uncomment X and Y
comment E
Uncomment BMG
Still have to set height elsewhere. I have not had chance to go back and add that back in. There is some new code I don't understand yet.
For now you can just change
#define Z_MAX_POS 210 to #define Z_MAX_POS 205 then it will pass XYZ calibration.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Yes, uncomment X and Y
comment E
Uncomment BMG
Still have to set height elsewhere. I have not had chance to go back and add that back in. There is some new code I don't understand yet.
For now you can just change
#define Z_MAX_POS 210 to #define Z_MAX_POS 205 then it will pass XYZ calibration.
Forgive my ignorance, but I find this in the same file as the X, Y, and BMG uncomments? Much thanks.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
It is later in the same file, Configuration_prusa.h
However, if you download from GitHub now, I just added automatic adjustment of Z_MAX_POs upon defining BMB_Extruder.
Also merged in latest from Prusa/MK3.
Now you can just uncomment
//#define BMG_EXTRUDER //Kuo Uncomment for BMG 3:1 extruder. This also sets BMG height for you. MUST also send M92 E830 & M500 to set esteps
and special BMG height will be adjusted for you.
I ended up changing define Z_MAX_POS instead of my old way adjusting in the auto calibration routine. This was cleanest approach.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
It is later in the same file, Configuration_prusa.h
However, if you download from GitHub now, I just added automatic adjustment of Z_MAX_POs upon defining BMB_Extruder.
Also merged in latest from Prusa/MK3.
Now you can just uncomment
//#define BMG_EXTRUDER //Kuo Uncomment for BMG 3:1 extruder. This also sets BMG height for you. MUST also send M92 E830 & M500 to set estepsand special BMG height will be adjusted for you.
I ended up changing define Z_MAX_POS instead of my old way adjusting in the auto calibration routine. This was cleanest approach.
Thanks so much! So I followed all the instructions and compiled the firmware sucessfully and installed the .9 moons. The Y axis works perfectly but the X axis doesn't even move. If I try to move the X axis in the menu or auto home it just makes a big noise and causes a lot of vibration but the X doesn't move a mm left or right. My belt is not too tight and it moves very easy manually. I am sort of baffled as to what it could be. Perhaps I will try to recompile the firmware? Any insights on what it could be?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
It is later in the same file, Configuration_prusa.h
However, if you download from GitHub now, I just added automatic adjustment of Z_MAX_POs upon defining BMB_Extruder.
Also merged in latest from Prusa/MK3.
Now you can just uncomment
//#define BMG_EXTRUDER //Kuo Uncomment for BMG 3:1 extruder. This also sets BMG height for you. MUST also send M92 E830 & M500 to set estepsand special BMG height will be adjusted for you.
I ended up changing define Z_MAX_POS instead of my old way adjusting in the auto calibration routine. This was cleanest approach.
Sorry for the double message but could not edit. Sometimes when I try to move the X axis in the menu or autohome it also moved the Z axis up a bit and moves Y and then restarts the machine. But X never moves. Very odd behavior.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
That is totally bizarre behavior.
Three things come to mind
1. Motor harness mismatch can cause motor to not move. There are two pinout standards. Get a mismatch and stepper only makes a tiny single move and stops. These work with Moons https://www.amazon.com/gp/product/B07CBV8DVZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
2. Firmware/EEPROM corruption. Do a full factory reset/delete all data
3. Defective stepper motor. Move to axis that works to check motor.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
For Moons, wiring harness wires should be in the sequence shown in attached picts.
OMC motor connection
Stepper online (OMC) motors don't have a connector. You need to add one as below...
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
My feedback after switching to the Trinamics 1.8° for X/Y and a Moons 1.8° as extruder:
- Creating all the custom wires did take way longer than expected. The tiny connectors are a pain without a proper crimp tool.
- Changing the extuder motor requires a full extruder disassembly.
- All motors worked right away without any firmware or hardware mods.
Extruder motor:
If you have any trouble with heat creep and/or your extruder motor getting way too hot for PLA, go for the Moons motor. Mine went from >90°C to <60°C in the same conditions. No more jams, none at all, even if the ambient temparature is above 60°C.
X/Y - Axis:
The Trinamic motors are super silent. I honestly didn't know that the MK3s could print that silent. Normal mode is like stealth mode with stock motors, stealth is pretty much no motor noise at all. Also I can now print a bit faster with same quality results. When printing ghosting / ringing test cubes, I cannot spot any ghosting anymore at [0.2mm/quality preset]. Speed preset looks a lot nicer as well. I don't know if thats worth 100$ in new motors, but hey, I've found two used ones for 40 bucks total, so why not.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
That is totally bizarre behavior.
Three things come to mind
1. Motor harness mismatch can cause motor to not move. There are two pinout standards. Get a mismatch and stepper only makes a tiny single move and stops. These work with Moons https://www.amazon.com/gp/product/B07CBV8DVZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
2. Firmware/EEPROM corruption. Do a full factory reset/delete all data
3. Defective stepper motor. Move to axis that works to check motor.
So it was actually very sneaky—I ordered the cables you recommended but two of them were pinned one way and two the other. Obviously the X axis got one of the wrong ones.
Also for anyone having homing issues: I find that sometimes if it is giving me problems I jsut turn off and manually move the X carriage to the right side and then it is able to home effectively.
Thank you so much. I am really amazed at the time you put into this and the technical prowess you have. I’m not a total idiot when it comes to this stuff, but suffice it to say I would not have been able to improve my Prusa so much without others forging ahead. I will post some before/after print pictures so people can see what the results are with the Bomdtech.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Happy you got it solved. That IS pretty awful having two different pin arrangements in the cable package.
Do two things to hopefully solve your homing issue.
1. Relax and reclamp the extrude cable bundle at the EINSY box while carriage is pretty far left.
2. Slightly increase x-belt tension. I usually aim to make 3 mm mid-belt deflection the amount at which further deflection feels more difficult. Deflecting the belt with the far end of your Allen key rather than directly with your fingers makes that change more obvious.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
So here are the results I am getting, going from stock to stock with some tweaking, then adding the Bondtech, and finally .9 moons on X and Y. The VFAs tend to show up better in .1 prints so there is a mix of both .1 and .2 test objects. I made a couple bigger cubes to try and get a better idea of surface quality than just a small test cube. Also used some of that Prusa gray that shows all imperfections so easily. One thing I noticed is that the VFAs do come back if you have something at a 45 degree angle even with the .9 moons. I am guessing the amplitude of both X and Y imperfections is additive at that angle. I guess Ill just try and position to avoid that.
Overall I am quite pleased, but I feel like my results are not quite the mirror finish yours have. This could possibly be other factors than VFA as I know you put a lot of effort into getting everything parallel and planar. Take a look and please let me know if you think one of the moons is not up to snuff. I have another one laying around I can swap in.