Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
THAT is a rebuild!
n my X-axis, Like guy.k2 mentioned... i am having homing issues and it is irratic. What happens is that it will bounce the corner once then when it returns to the right, it just stays there with the motor making a horrific noise... Then the printer reboots thus attempting to reconnect to the octopi and do t all over again.... Of course I was kinda ahead of myself knowing that this is still in testing.
X-axis is far harder to get homing reliable. Despire TMC2130 spec sheet suggestions, I found going slower was more important than altering velocity or pre-travel distance. When stallguard sensing isn't working well, not only do you get erratic failures and printer resets when homing X, but it also becomes sensitive to belt tension. Get tension too low or high and x homing would fail.
Current firmware revision has slower homing rates for x and y. With a good Moon's 0.9 on x and current branch changes, my x has yet to fail homing. It works with belt tension going from too tight to too loose. I would change your x-motor to another unit if you can't get it to home reliably with slower homing feed rate. I know the Moons works. Still need to go back and re-verify OMC on x-homing.
Some Moon's motors are not built well. I had two bad ones arrive in a row. With nothing connected, turning the shaft of a 0.9 Moons should let you feel fine, evenly spaced detents. If you feel more widely spaced, hard detents that remind you of how a 1.8 motor feels, you have a unit that won't behave well on X axis.
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
[quote=guy.k2 post_id=135878 time=1553981674 user_id=95162]
THAT is a rebuild![/quote]
Thank you! It was definitely time. Warped steel braided belts (don't judge me) and igus bearings printing nonstop in 60c... It was time 🙂
X-axis is far harder to get homing reliable. Despire TMC2130 spec sheet suggestions, I found going slower was more important than altering velocity or pre-travel distance. When stallguard sensing isn't working well, not only do you get erratic failures and printer resets when homing X, but it also becomes sensitive to belt tension. Get tension too low or high and x homing would fail.
I noticed this when I actually has some success on getting the X to finally home. When I first installed it I had it way to tight, but this is the main reason from the get-go... I figured I would have homing issues since I would have homing issues when the steel belts eventually got warped on the old setup with 1.8s. I switched everything to gates belts. Now it is way looser than I like and I am still having issues. Maybe the cable bundle is the issue, but whatever the case, it is sensitive. I will probably convert the bundle to a cable chain eventually and retest the current motor.
Current firmware revision has slower homing rates for x and y. With a good Moon's 0.9 on x and current branch changes, my x has yet to fail homing. It works with belt tension going from too tight to too loose. I would change your x-motor to another unit if you can't get it to home reliably with slower homing feed rate. I know the Moons works. Still need to go back and re-verify OMC on x-homing.
Yea... The story on this particular stepper is insane. After a week in customs, I am honestly afraid to return it at this point. The stepper feels smooth, and it has nowhere near the feeling of a 1.8. Still... You could be correct... I may just have to order another one. I have quite the collection of steppers now 🙂 I just didn't know if you would recommend slowing this down more, and would it make any difference? I might play around with it tonight since I have the backup printer here with me.
Some Moon's motors are not built well. I had two bad ones arrive in a row. With nothing connected, turning the shaft of a 0.9 Moons should let you feel fine, evenly spaced detents. If you feel more widely spaced, hard detents that remind you of how a 1.8 motor feels, you have a unit that won't behave well on X axis.
Its smooth and evenly spaced compared to the 1.8... Maybe it is the cable bundle like I mentioned.. It has no spring, but the diagonal force might be throwing it off and I don't know it.
Again, Thank you for all your testing and help!
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
You might also try swapping your Moon's 0.9 that is on Y to your X axis.
As far as other adjustments to try....
in Configuration_prusa.h, try lower HOMING_FEEDRATE_X to about 2000
//Kuo set the homing speeds (mm/min)
#ifdef X_AXIS_MOTOR_09
#define HOMING_FEEDRATE_X 2000 // Kuo slower feedrate needed for reliable X 0.9 degree motor stallGuard
#else
#define HOMING_FEEDRATE_X 3000
#endif
Could also add a slightly higher TMC2130_SG_THRS_X_HOME of 4 to 6, but I would try lower homing speed first.
#ifndef X_AXIS_MOTOR_09 //Kuo
#define TMC2130_SG_THRS_X 3 // stallguard sensitivity for X axis
#define TMC2130_SG_THRS_X_HOME 3 // homing stallguard threshold for X axis
#else
#define TMC2130_SG_THRS_X 4 // Kuo in case different needed for 0.9 degree motors
#define TMC2130_SG_THRS_X_HOME 4
#endif
I went ahead and slowed homing and tweaked TMC2130_SG_THRS_X in my branch while merging in latest changes in Prusa's main mk3 fork.
You mentioned your collection of motors leftover from testing. Here is mine...
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
You might also try swapping your Moon's 0.9 that is on Y to your X axis.
I was actually going to try that next since I think I am dead in the water on the .9 LDO stepper.. Still confused on why it just moves a little bit then stops... At least I have a moons 1.8 that works phenomenal as a backup. Going to return the LDO and see what happens with a replacement... Just sucks ripping down the bondtech everytime I want to test. I am going to try the firmware suggestions first and see what happens with that since the X axis is a easy swap and firmware change.
Thank you for your help!
You mentioned your collection of motors leftover from testing. Here is mine...
motors.JPG
Mother of god! So far I only have 6 off this machine that I am not using 😎
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Yes, there is definitely a cost to doing motor testing.
Your "bad" LDO was wired correctly right? The LDO's 0.9's with JST-PH pins I tested have different pinout from moon Moons' JST-PH.
1 2 3 4 5 6
Moons have A coil on 1 & 3 / B coil on 4 & 6
The LDO's had A coil on 1 & 4 / B coil on 3 & 6
That would be a problem if you used the same cable harness without moving plug pins.
If you get both coils connected to their respective pins, but find motion is backwards, reverse the pins of ONE coil to make motor spin in other direction.
The 1.2 amp rating isn't great, but IIRC extruder is always spread cycle and we actually do control drive current for that motor.
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Your "bad" LDO was wired correctly right? The LDO's 0.9's with JST-PH pins I tested have different pinout from moon Moons' JST-PH.
Oh my... again you are awesome! I was tired after 3 rebuilds of the extruder and decided to sleep on it. This morning, made a test cable and changed firmware to try your suggestion. Changed firmware with spacemarines firmware changes and it works beautifully. My next prints will be towers to provide feedback, but as of right now it is printing a product that I sell for RC cars out of CF/PC to catch up with production It is flawless so far!
Just comparing to the moons 1.8 so far. I am running about 15 degrees lower inside the enclosure Fahrenheit on the stepper with a heatsink.
Retractions seem more accurate with the same gcode. Maybe its just me, but this seems way smoother as well.
On the X axis... again... you ... are... awesome..
I swapped the motors with a little bit of improvement but was still having intermittent homing issues after the enclosure was hot. Decided to try the firmware changes, and It works great! Seems like the slower the better.
Anyway... I am super excited that this works along with all my other improvements! I will post pictures of my testing once I get the rest of the little bugs worked out!
Re: VFA fix summary and shopping list
Both choices of motor require grinding a shaft flat for the y-axis.
I thought both (the Moons and the OMC) have a flat shaft, or am I wrong?
Are there any known problems with the 0.9° motors on X and Y when printing fast?
Im curious to know, because I often print things, where surface finish isn't the priority, with perimeter speeds set to 100+ mm/s and infill with 200 mm/s.
I'm yet unsure if I buy the Moons or go with the OMCs. Reading about the quality issues with the Moons and the risk of getting a poor one, makes me wonder if it's worth the risk. I life in germany and have to order the Moons directly from them in china. Which makes it more expensive (tax + shipping) and returning might be more of a problem as when they were bought at amazon.
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I thought both (the Moons and the OMC) have a flat shaft, or am I wrong?
They do, but the flats end too far from motor body. When pulley is placed to align Y belt very few drive pulleys will engage limited flat portion. This only happens on Y. On X and E, their existing shaft flats are adequate. Fortunately, grinding a flat only takes 30 seconds. Just double bag the motor so NONE of the grindings get into the (magnetic!!) motor.
Deciding between Moons and OMC ..... I am personally leaving OMC's mounted and setting linear correction to 1.080 for those motors. Expense is a real issue especially after my running into a couple bad units.
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
On the X axis... again... you ... are... awesome..
I swapped the motors with a little bit of improvement but was still having intermittent homing issues after the enclosure was hot. Decided to try the firmware changes, and It works great! Seems like the slower the better.
Well I have to take this back for a bit while I adjust on my test machine. ( not the awesome part )
All of a sudden, I started having homing issues again on X axis. I decided to just swap the X out for my moons 1.8 just to get my printer running correctly without homing issues. I slowed it down more, just to make the issue even worse. I will add the X axis 0.9 to my test machine and see if I am still having issues. The Y and E are both running 0.9 with absolutely no issues. I did have a few times where the Y axis shifted layers less than a mm but I was noticing the stepper getting really really hot. I added a heatsink to the Y stepper (maybe a fan later) and I have had no issues since.
So far, this has made my printer 100% better! With the bondtech and the .9, it has improved even more! I need to get some PLA and start making towers. I think I am going to borrow my buddies stock silver filament since that seems to be the baseline.
Thanks again!
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Any association with temperature for the x-motor homing coming back?
in Configuration_prusa.h
Try adjusting the homing TMC2130_SG_THRS_X_HOME between 3 to 7 and see if it helps.
Also, If you compile with the follow two defines on, will be a bit easier to various thresholds. Lets you set temporarily set threshold without reflashing firmware. Adds some other stuff to menus. So don't go using commands you don't recognize.
#define TMC2130_SERVICE_CODES_M910_M918 // kuo exper define for tmc 2130 debugging
#define TMC2130_DEBUG // kuo exper define for tmc 2130 debugging
Then via terminal you can send g-code command to set TMC2130_SG_THRS_X_HOME
M924 X3
This setting is temporary and goes back to setting in firmware if printer restarts or reboots. That includes after stuttering homing failures.
If you find a usable TMC2130_SG_THRS_X_HOME, you can set that in your copy of firmware. Let me know what you end up with.
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I thought both (the Moons and the OMC) have a flat shaft, or am I wrong?
They do, but the flats end too far from motor body. When pulley is placed to align Y belt very few drive pulleys will engage limited flat portion.
Thank you very much for that clarification!
So this wouldn't be an issue for people with a BEAR frame (as I have one and I think you also?).
I have mounted the pulley on the Y motor the same way as it is on the X motor (grub screw away from the motor). I wanted the beld as close as possible to the motor to minimise leverage on the shaft. On the BEAR frame the motor mount can be freely positioned on the extrusion, so belt alignment isn't an issue 🙂 .
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Yes. It's not a problem on a Bear frame. I'm actually on a reinforced, stock MK3 frame.
However, using the Bear axis and extruder for their easier servicing and adjustment. BTW, if you ever rebuild your Bear extruder, definitely grab my STL's for the body, idler door, x-carriage and cover. Together, they make motor service a LOT easier. I could not do my extruder motor testing without the mod. For normal user, it still allows super easy motor service
https://github.com/gregsaun/bear_extruder_and_x_axis/issues/32
The ones to grab are at end of that issue page.
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Will you be posting these files in the Prusa Community Forum - Original Prusa MK2/2.5, MK3, MMU2, and Custom Mods on FB?
I just ordered the MS17HA2P4100. Doing my own firmware is deep water for me 🙂
Love all the effort you put into this.
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Will you be posting these files in the Prusa Community Forum...
No. Due to their various security and personal data monetization issues, I will not use Facebook.
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Will you be posting these files in the Prusa Community Forum...
No. Due to their various security and personal data monetization issues, I will not use Facebook.
So you have the same frustration that I run into when people say "check the Facebook group for the info". That's not helpful to people who don't use Facebook.
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Will you be posting these files in the Prusa Community Forum - Original Prusa MK2/2.5, MK3, MMU2, and Custom Mods on FB?
Facebook is a really aweful place to post files. Everything is very confusing, as you can not make categories, have proper descriptions, etc...
It makes much more sense to post a message on facebook with a link to this thread or post.
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Will you be posting these files in the Prusa Community Forum...
No. Due to their various security and personal data monetization issues, I will not use Facebook.
Thirded. I also refuse to use it; I'm sure there's a wealth of prusa info there but I guess I'll never see it.
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Hi,
Any sugestion how to ge homing to work?
Managed to get xyz cube printed, after that im not able to home.
When i started that print the belts was totaly loose.
First print looked realy nice 🙂
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Which motors did you use on each axis?
Homing hit must be good plastic vs plastic contact. Check that none of the wires or twist ties are you actual initial contact.
You are using my current firmware, right?
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Im using the MS17HA2P4100.
No cabels or twits between plastic parts.
Im using the firmware 3.7.0-2201