RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Any idea what might be causing this banding? this looks exactly like the linearity issue which the 0.9 motors are supposed to be fixing. This is with moons 0.9 on X, Y and E, bondtech type extruder on a prusa bear.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
It looks similar, but I see some differences that suggest it is not an extruder motor non-linearity issue. The diagonal waves generated by the extruder motor are uniformly spaced and straight. These are definitely curved and non-uniform. So, it is nearly periodic, and shifts in phase. I would be looking for a mechanical issue that is able to alter the filament feed on a semi-periodic basis.
Trying to think of things with a long enough period and recurrent.
One would be a spool that isn't unwinding uniformly, but gets periodically jerked to free more filament as the x-carriage moves.
Another is a loose Bondtech drive gear set screw impinging on its mating idler gear.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Also, check your pulleys/drive gears. I had similar effects on a skelestruder (belt drive) with a 3d printed 16t drive gear. They went away when I switched to a machined pulley on the motor.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
My phone says ~80 Hz on Y
Posted by: guy-k2
Prusa X top 129 Hz
Bear X top 172 Hz
Wow, that's quite the difference between you two. My Y was also in the 150Hz range, which I thought was okayish. Now I went all the way down to 80Hz. The belt feels quite loose, but still works. And for the moment, it seems to have worked! It homes! Yay, thanks guys.
Which print settings do you use for these perfect looking calibration cubes?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
As noted it's really hard to get a frequency reading; my numbers could very well be completely wrong...
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
and I'm generally using Bobstro's profiles with speeds slightly tweaked for a Skelestruder.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Haha, I spoke too soon. After one successful print, Y homing success rate went from 100% down to 0% again. Motherf%$#5$#
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Guys I know it has been said a lot but don't look past the belt tension - I have a sweet spot on X where if it is just slightly tighter homing fails, slightly looser and false crashes. The difference between working and problems is two turns of the tensioner. My set up is slightly different with the linear rails set-up and only change to @guy-k2 firmware was increasing SG +1 on X and Y.
Homing issues - if you are sure your axis is perfect and didn't play around too much with the firmware I'd suggest working through belt tension. Start very tight and gradually loosen it one turn at a time - you'll find the sweet spot.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Omnissiah, I have said it before in this thread and you may have already checked, but please also triple check the wires on your extruder. None of them can be making any contact with the frame or EINSY box. If anything prevents the one and only hit from being a solid plastic vs solid plastic hit, homing will be unreliable.
Look in particular at the noctua fan and extruder motor cables where they emerge from behind the noctua fan and go around their guidance slot. If they protrude laterally beyond the guide fins, they create a soft bumper that ruins the homing signal.
The extruder cable bundle must not touch the EINSY case at full leftward x-position. Any touch by a zip tie or techflex wrap is a problem.
On the y-axis, switching to a motor mount that stops against the belt mounting clip instead of the rear left bearing may improve y-homing reliability.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
PSA: the ZMax for the Mk3S skelestruder define is NOT correct.
This is because of how PR did the change to increase the Z height. Details here:
https://github.com/vertigo235/Prusa-Firmware/commit/10d5f1d8a45af93e328a4bcd60bcfddbf7e9fb78
It should be left at 210 (or possibly bumped a smidgen to 213). I will fix this later; I imagine Guy's got a lot on his plate ATM trying to resolve merge conflicts, if he's planning to merge the 3.8.0 RC.
(Now that M350 works I'm taking stock for a spin with my 0.9 degree X/Y.)
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I'm seeing some interesting behaviour; after a Y home the screen will blank, the bed will creep forward at about half speed, and then the printer will reset.
Does that sound familiar if the stallguard isn't right? Or is that something else?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
after a Y home the screen will blank, the bed will creep forward at about half speed, and then the printer will reset.
Yes. That is exactly what the printer does when Y homing fails.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
after a Y home the screen will blank, the bed will creep forward at about half speed, and then the printer will reset.
Yes. That is exactly what the printer does when Y homing fails.
Thanks. The funny thing is, I duplicated the various homing settings from your branch over to stock once I started seeing this... and it made no difference. Given all my Y issues I wonder if I just happen to have an unusual or at-tolerance motor.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I got Y to home by setting TMC2130_SG_THRS_Y_HOME all the way down to -2. It will successfully home at about 1/3 of all attempts, which allows me to at least print some replacements for now. Any lower and I'll be getting false positives. guy-k2, I'll be printing a modified Y motor mount with endstop like you suggested. Thanks for the tip. But first I need to solve another problem.
I'm trying to calibrate the K-Factor for Linear Advance 1.5 for my filament (XT-CF20) which prints at 260°C. I've done this countless times for other filaments with the help of the Marlin pattern generator ( http://marlinfw.org/tools/lin_advance/k-factor.html ). However when calibrating this time, it prints the first line (K=0) and then... resets the printer. No messages, not even on the serial console. What's going on now? This makes no sense.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Knock on wood, but I'm currently actually running stock firmware with OMC 0.9 degree motors and the M350 patch. I've given up on crash detection for now as it was not working reliably for me with either Guy's firmware or stock. I cannot recommend enough not to overlook
G28 [axis] C
in regards to homing/testing. The printer actually runs this during the first setup wizard and seems it should definitely be done again if you alter motors. This is the internal TMC2130 calibration routine that was referred to earlier, I think. It's also an excellent test of homing since it basically does 16 bump homes in a row. When I was having issues I could not get one successful completion of that command without a fail and printer reset.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Ok, I fixed the crashing firmware. Somehow my EEPROM got corrupted. M503 reported:
echo:Maximum feedrates - normal (mm/s):
echo: M203 X300.00 Y300.00 Z25.00 Einf
...
echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum XY jerk (mm/s), Z=maximum Z jerk (mm/s), E=maximum E jerk (mm/s) echo: M205 S0.00 T0.00 B0.00 X10.00 Y10.00 Z0.40 Einf
inf? infinity? Huh. What settings do you guys have in there by default after a reset? Setting these to sane values with
M203 E120 M205 E1.5
Fixed the crashes. PrusaSlicer did this at the start of each print, Marlin's generator doesn't.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I don't think the factory reset works right. I did one after switching from Guy's firmware to a tweaked stock and the esteps were fixed at 8 instead of the default 16.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
https://github.com/prusa3d/Prusa-Firmware/issues/2099
Lucky for you I hang on to my M503 dumps for faster setup after factory reset. Note I've pruned out lines for things that are customized on my f/w:
SENDING:M503
echo:Maximum feedrates - normal (mm/s):
echo: M203 X200.00 Y200.00 Z12.00 E120.00
echo:Maximum feedrates - stealth (mm/s):
echo: M203 X100.00 Y100.00 Z12.00 E120.00
echo:Maximum acceleration - normal (mm/s2):
echo: M201 X1000 Y1000 Z200 E5000
echo:Maximum acceleration - stealth (mm/s2):
echo: M201 X960 Y960 Z200 E5000
echo:Acceleration: S=acceleration, T=retract acceleration
echo: M204 S1250.00 T1250.00
echo:Advanced variables: S=Min feedrate (mm/s), T=Min travel feedrate (mm/s), B=minimum segment time (ms), X=maximum XY jerk (mm/s), Z=maximum Z jerk (mm/s), E=maximum E jerk (mm/s)
echo: M205 S0.00 T0.00 B0.00 X10.00 Y10.00 Z0.40 E2.50
echo:Home offset (mm):
echo: M206 X0.00 Y0.00 Z0.00
echo:Retract: S=Length (mm) F:Speed (mm/m) Z: ZLift (mm)
echo: M207 S3.00 F2700.00 Z0.00
echo:Recover: S=Extra length (mm) F:Speed (mm/m)
echo: M208 S0.00 F480.00
echo:Auto-Retract: S=0 to disable, 1 to interpret extrude-only moves as retracts or recoveries
echo: M209 S0
echo:Filament settings: Disabled
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Thanks man!
Unfortunately, M503 does not show the entire contents of the EEPROM. Things like XYZ calibration data, bed levelling reference or belt tension are also stored, but can't be accessed 🙁 I wish there was a way to save/restore these aswell.
So you're running Prusa's firmware now? Did you need to do any modifications aside from setting up the header (.h) files and setting μsteps and steps per mm? Kuo, did you do any changes aside from headers?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Guy's other changes pertain to stallguard tweaks, and some load distances for different extruders.
I did have to apply the M350 patch to make it work for X/Y/Z instead of just E, there is an open PR for this issue. ( https://github.com/prusa3d/Prusa-Firmware/issues/2024)
Additionally, as I have a skelestruder, I need to adjust filament load/unload distances as it is 10mm shorter than stock.
Beyond that, no. Factory reset, tweak usteps and verify steps/mm is still correct, and I was off to the races.