RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Hello, I'm sorry for invading the thread but i need some help. About a month ago I've built a Prusa Bear based on Mk3s and with 0.9 Moons motors on X, Y and E. I flashed the firmware for 0.9 motors and everything worked fine immediately, so I enjoyed printing for a month without any issues. Out of a sudden on one print I started getting crashes on Y. I was using the stock Mk3s belt tensioner (under the bed) with the stock bear pulley holder. Since than I changed the belt holders, installed a front Y belt tensioner, realigned the whole Y to make sure everything's straight but I keep getting crashes on Y. I'm using genuine gates belts (bought from a gates dealer in Germany to make sure they are really genuine) and good pulleys. When I perform a self test I keep getting loose pulley errors until I tighten the belt really good - only than I manage to pass the self test but I still get the crashes on Y. Any idea what to do to eliminate that?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
I finaly ordered and received my five Stepperonline 17HM15-0904S motors.
When I unboxed all of them I discovered that I got different batches:
- 3x build date 20190103 with the modelnumber as a sticker on the motor
- 2x build date 20190116 with the modelnumber laser etched into the motor
Sadly other things happened and I can't test them at the moment (earliest in a few weeks).
But when I turn them with my fingers, the two newer ones seem smoother and I think needing a little bit less force to turn. The steps are less pronounced on them.
So in lack of experience I'm a little bit lost at the moment in what I should do. Which one is bad, which one is good, or are both ok.
Is the experience with the Stepperonline motors in this thread based on the ones with the sticker or with the laser etch?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Which one is bad, which one is good, or are both ok.
Probably both are OK. The ones I have are stickered ones. If the etched ones have even softer detentes - they are likely even better. In general, the softer and finer the detentes feel when you manually turn the shafts, the less the motor produces VFA's
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Y-crashes after a month of uneventful printing suggest a mechanical change has occured. Moste likely canddates are a cable now strking something or a bearing going bad. You're going to need to do some testing of the y-carriage with belt ---> COMPLETELY DETACHED!!! <----. Check for any binding and replace bearings if needed. Then floss the idler pulley with the belt in your hands to feel whether it rotates completely freely. Look under carriage and around printer for obstructions.
Or you could just switch to Stealth mode or turn off crash detection if nothing at all shows up on mechanical workup.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Just a heads up, this appeared in the firmware github recently. Future builds will probably have linearity correction disabled...
So no more stock firmware with motors that need said correction for better performance... :-/
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Future builds will probably have linearity correction disabled
How nice.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
looks like they ran out of room to add the multi-sheet tracking live Z
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
3.7.2 forever, I guess... I ordered an OMC 0.9 degree recently, so naturally I'll need the combo of e-steps, usteps and linearity.
I'm guessing they can't save on flash space by e.g. splitting the build languages, e.g. two bundles with half of the translations each. Of course it complicates the build system, but at least you wouldn't have to trade features for a while longer...
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Just a heads up, this appeared in the firmware github recently. Future builds will probably have linearity correction disabled...
So no more stock firmware with motors that need said correction for better performance... :-/
Which steppers need it?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Per this thread, the OMC/stepperonline motors perform better than the Moons' with it enabled. I have values dialed in for my skelestruder which has an OMC pancake and will need it for the OMC 0.9 degree motor I ordered.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Per this thread, the OMC/stepperonline motors perform better than the Moons' with it enabled. I have values dialed in for my skelestruder which has an OMC pancake and will need it for the OMC 0.9 degree motor I ordered.
Thanks! Yeah, then it seems obvious those with OMCs need it, and it is good that albe-g says it is not permanent. 🙂
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Agreed, that's why I did say "probably". 🙂 But figured it warranted a heads-up here since it's likely the forked branches might do a merge prior to the next official release.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
First of all thank you for your efforts guy-k (and contributors)!
I've been following this thread for a while and todoay I finally got my 0.9 OMC.
Installing the firmware was straight forward. I'm using the LA 1.5 0.9 motor branch and it is working good so far. Calibration was no problem after I did a gcode reset and also a factory reset via the printer reset button. Then I set linearity correction to 1.130.
First issue was though that I had several crash detections during my first test print. The factory reset reactivated the feature and I forgot to deactivate it. So I deactivated crash detection and restarted the print. And again at layer 3 crash detection was detected though crash detection is disabled (!). Odd. I then activated stealth mode and the printer finished the job without false detected crashs.
Picture of the first test print:
My question is, why does crash detection still detect false crashes though I have disabled crash detection in "normal" mode?
Atm I'm printing in stealth mode. I guess there is no disadvantage in printing in stealth as a standard setting?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Just got and installed a StepperOnline (laser etched) on Y. Stock firmware, ran M92 Y200, M350 Y8, and it works a treat as a drop-in. Running a linearity correction tower for XY now. Only observation is a very high (~15+ kHz) whine from the stepper, reminiscent of a CRT tv. Not obnoxiously loud, but present if you listen for it.
Has anyone had to alter motor currents for these 0.9 degree motors w/ M907?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Update on my bigger test print with stealth mode. I got some minor layer shifts along the x axis. When I start a Selftest the tester reports "loose Y axis" and cancels. X result is OK. I checked the axis and everything is fine on x and y. Belt is also not loose or too tight and the screws on the motor are tight.
The vertical noise is gone which is very nice but now I wonder what values need adjustment to get rid off the layer shift.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
#Update 3
Found the culprit: Grub screw thread was busted. They don't like to be swapped that often I guess. Threw in some fresh spares and layer shifts are gone. Printing at normal mode works just fine - printing a test cube right now. 👍
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
The results from my swap above looked good so I went and bought a second OMC for my X axis.
Rock on!
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Although you can use stock firmware by altering e-steps and microstepping, there are further tuning refinement for TMC2130 parameters, current, running speeds in my 0.9 degree support firmware.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Which is why I love your firmware.