Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
That combination should be working. I can't confirm the firmware version because those are Prusa's. I don't alter the version number when I update my branch. When did you download from my Github?
The things I would check are....
Does it home better with Z near bottom vs top? I had problems with it at high z's, but got it working with firmware that is currently online at my branch.
Belt tension must not be super tight or too loose.
You could also try changing TMC2130_SG_THRS_X_HOME to 6, 7 or 8. That would be changing the LAST "4" in the below
#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
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I remove everything and checked all cables, tightend the belt.
Had a glas of wine and it worked.
Not sure if it was the wine or the things u sugested 😉
Thanks for helping me out.
First print in progress now.
Glossy black 😐
All the lines will show if there is any.
We will see tomorrow and i will post a pic.
Re: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Glossy black PETG is my favorite and most used filament. Yes, EVERYTHING shows in the reflections.
I think you need more wine.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Been checking out this thread and I'm very interested in switching to .9 steppers, but I'm sad from all the features I want being spread across so many different custom firmware branches.
I've grown to like Vertigo's firmware's ( https://github.com/vertigo235/Prusa-Firmware/releases), and I would like to keep using his, but adding in the changes you have done to get .9 steppers working.
Is there any way to get an abridged list of changes to go by to make it easier to combine the firmware's into one?
As for the issue of grinding the motor shafts, I could see this as an issue on the original frame, but I don't think there's any need for it if you have a Bear frame. I actually flipped my Y-axis pulley some time ago because having the belt at the far end of the shaft was putting stress on the stepper bearings and I was getting an odd resistance. Flipping the pulley put the torque closer to the motor and smoothed out my Y movements. All I had to do was move the Y-motor mount over a few mm and there's no need to grind on any shafts.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I've just recently installed Trinamic QSH4218-51-10-049 1.8° μ-stepping optimized steppers on my X and Y axis, along with an LDO LDO-42STH25-1404MAC 0.9° pancake stepper on a Bondtech 1:3 extruder.
The printer is noticeably smoother and quieter, and the prints I find have improved considerably. Does anyone on the thread suggest a test print to compare the quality?
Also any suggestions on Z axis steppers that'd be smoother/quieter than the original LDOs?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I'd suggested this in the E-gearbox thread but I'll re-post here... but has anyone got the ambition to try a gearbox at 2:1 or higher on X or y instead of 0.9 degree motors? There's a thread here where someone made it for their extruder with great results; seems to reason a similar benefit could be observed for very little cost on X and Y as well (with stock motors, no less) since there seems to be more than enough room to fit it.
I'd volunteer my own time if I already had the needed mechanical parts on hand but as it is I've spent a little too much of the slush fund on my printer already recently...
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
along with an LDO LDO-42STH25-1404MAC 0.9° pancake stepper on a Bondtech 1:3 extruder.
Me and guy.k2 also had that 0.9° stepper and neither of us were able to get good results. It seems that it has too little torque, resulting problems during retraction/unretraction. Switching back to 1.8 ° immediately solved this. We also analyzed the difference in quality (uniformity) between 1.8° and 0.9° on a 3:1 geared extruder and we did not see the slightest difference. A good place to start reading is here:
and here:
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I wasn't asking about gearing a 0.9 degree motor for better performance, I was asking whether it would work to gear a 1.8 degree X or Y motor to get the same performance as a 0.9 sans gearbox, without the added cost and other side effects that come with swapping to different steppers.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I know, my reply was aimed at Vojtěch. (See my quote)
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I know, my reply was aimed at Vojtěch. (See my quote)
Sorry, my bad. I just figured you were addressing multiple replies in your post like I often do. 🙂
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I wasn't asking about gearing a 0.9 degree motor for better performance, I was asking whether it would work to gear a 1.8 degree X or Y motor to get the same performance as a 0.9 sans gearbox, without the added cost and other side effects that come with swapping to different steppers.
Hey vintagepc, I just read through the whole thread and remember this coming up. I think the answer you're looking for is on page 4:
...
A 0.9 motor on the extruder is NOT the same characteristic as the stock 1.8 degree LDO motor or 1.8 Moons. It is a 0.9 degree motor. As such, it is better able to actually hit the EINSY requested microstep positions. The extrusion is thus more uniform, despite the same number of addressed steps. The extruder actually runs slow enough that the EINSY can step it twice as fast as stock motor - yielding double the addressable microsteps. I have support for that in my firmware branch, but have not been able to elicit much difference going to that many steps.
Yes, going to a geared setup is another way to improve monotonicity. By having the gearing, the motor has an easier time hitting difficult microstep positions and those positions are physically finer. However, we have basically proven that a 1.8 motor which is inherently less uniform simply never becomes that much more uniform even with Trinamic tuning. Physical motor step uniformity is a much larger determinant of step monotonicity than adding more micro steps.
Hence, a 0.9 stepper in the extruder position produces a more uniform extrusion - even in the absence of gearing to reduce torque load.
I hope this helps!
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
That's helpful - though I don't think anyone has posted pictures of such a setup's prints yet, have they? That's really what I was interested in.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I came across this thread and perhaps this is why i am having a terrible time printing. I switched over to the 0.9 moons *100 motor some time ago for the extruder. I was able to print using the MK3 set up without much issues, but now that I have switched to the MK3s with the IR in the MMU2s position, I have a terrible printing problem. Starts out ok, but flow eventually stops and I run the filament change to keep going. I have tried every suggestion out there without success and am focused on the motor now. I was thinking of increasing the amps to see if it would help torque the filament. out....
But if I read this thread right the motor doesn't really have the torque to begin with?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I'll definitely read those threads, but so far the LDO 0.9° pancake doesn't give me any trouble - other than being a bit noisier than I'd like.
Before installing it, I modified the firmware to 16x μ-stepping so as not to run into limitations of the Einsy and Marlin and I increased the currrent by 40% as well, because the LDO 0.9° pancake has a nominal current of 1.4A, while the standard Prusa extruder has a nominal current for 1.0A. Given that the Einsy has a maximum current of 0.96A RMS, it'll never be able to run the LDO 0.9° pancake at full torque, but this should give roughly half the available torque. It runs warm, but not hot, even on demanding prints.
The quality of prints has definitely improved compared to before, but then I installed the Trinamic motors for X and Y at the same time, so I don't have data for the isolated effect of the LDO 0.9° pancake installation. I can swap the motors around and do some tests ... are there any recommended test prints that excercise extruder linearity?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Hmm, extrusion restart issues? Yes, that rings a bell. Certainly something I need to compare.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
guy-k2. I have a Prusa Mk3 and just ordered 4x Moons 4100 stepper motors. One for the extruder , one for the Y axis, one for the X axis, and one for a spare if one of the others are bad. Do you think the I should have ordered 2 more for the Z axis or do you believe that the stock ones are fine for the Z axis?
Jim
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
and guy.k2 also had that 0.9° stepper and neither of us were able to get good results. It seems that it has too little torque, resulting problems during retraction/unretraction.
So I've read those threads and yes, I'm having the same problems with the 0.9° and retraction.
And I think I have an idea why.
The LDO-42STH25-1404MAC has a maximum speed at 24V and full torque (that means 1.4A, that the Einsy can't even do) of 3.9 rotations per second. And the standard retract speed of 35 mm/sec translates to 4.5 rotations per second.
If we add the inertia to the load, it's clear that the motor is losing torque and skipping steps when retracting, because there is not enough drive voltage to overcome its BEMF and inductance. And I was wondering what those weird squeaky sounds were.
Ok, next step: Trinamic QSH4218-41-10-035 on the 3:1 Bondtech extruder.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Can't put those on the Z unless you also cobble together a solution for connecting the Z-screws. Those are integrated into the Prusa Z-motors. I have not messed with Z and given how slow z runs and its high gearing ratio, I doubt it would make much difference. You biggest improvements in descending order of importance...
1. Good bearings and rods (reduces random noise in print surfaces)
2. Y-axis 0.9 degree motor (worst axis for VFA's)
3. X-axis 0.9 degree motor (2nd worse for VFA's)
4. Extruder change to geared version or (almost as good switch to 0.9 full size motor)
5. Swap motor idlers to different make.
Fixing each prior item improves printer accuracy to the point that the next (largest of the remaining smaller) problem becomes the most evident.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Can't put those on the Z unless you also cobble together a solution for connecting the Z-screws. Those are integrated into the Prusa Z-motors. I have not messed with Z and given how slow z runs and its high gearing ratio, I doubt it would make much difference. You biggest improvements in descending order of importance...
1. Good bearings and rods (reduces random noise in print surfaces) Igus RJZM-01-08
2. Y-axis 0.9 degree motor (worst axis for VFA's) Moons 0.9 degree MS17HA2P4100
3. X-axis 0.9 degree motor (2nd worse for VFA's) Moons 0.9 degree MS17HA2P4100
4. Extruder change to geared version or (almost as good switch to 0.9 full size motor) Bondtech BMG-M with Mosquito Magnum hotend
5. Swap motor idlers to different make.
Fixing each prior item improves printer accuracy to the point that the next (largest of the remaining smaller) problem becomes the most evident.
Mine are in red.
Jim
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Jim,
Great setup. That's pretty darned maxed out I think. Nice mass reduction and gearing for the extruder too.
The only VERY minor possible niggles I can see are...
Watch the Igus bearings for stiction.
On the Y-axis, I get slightly less VFA with STEPPERONLINE 0.9° OMC 17HM15-0904S set to linearity correction 1.130. The OMC's are worse than the Moons when linearity correction is off, but slightly better than the Moons when linearity correction is set up. Linearity correction never tested out as doing anything good for the Moons 0.9's here.