Replacement A/B motors tuning help/insight

General Discussion
1

Basic Information:

Printer Model: Troodon 2
MCU / Printerboard: Octopus X7
Host / SBC Biqu Pi V 1.2
klippy.log

klippy.log (2.1 MB) (Dirty because of cartographer, nevermore, klipper maintenance, & LED effects)

Hi all, I could use some advice and insight after having recently replaced A/B motors and belts for the Troodon 2 I use at work.

Because I believe one of the motors developed a click, I replaced the original Moon’s motors (MS17HD6P420I-04) with LDO Motors 42STH48-2804AH from West3D, and belts with 6mm Gates GT2.

After installing the motors and belts and putting everything back together, I turned on the printer and set speed factor to 25% (I didn’t realize that that setting does not affect homing moves) I homed and then tried to QGL, but the printhead didn’t really move on QGL. I realized it was trying to use speeds/accels(400/12000) I had tuned/setup for the previous motors.

I turned up run current for the motors and modified the location of the controller fan to blow more directly onto those stepper drivers(with previous motors, run current at 1.2 triggered the OTPW flag). Drivers are BTT TMC2209 V1.3. BIGTREETECH TMC2209 V1.3 Stepper Motor Driver – Biqu Equipment

So I’ve got run current at 1.4(from 1.0), and had successfully ran Ellis’ speed and acceleration test at 550/8000 with 50 iterations last Friday. I believe starting\ending microstep differences were <5.

I thought I would be good to go, but on my first test print and multiple since, the steppers have skipped and moved out of position.

Yesterday while troubleshooting I realized the belts were looser than they were Friday. I guess they settled/loosened slightly over the weekend and I thought ok, that’s why it skipped while printing. So after adjusting belts I tried the same print again, a benchy plus a circular disc to see if a print defect had been cured by replacing motors/belts, and same thing happened; skipped once it got above first layer and tried to travel at 500/8000.

Trying to troubleshoot further I started reading about jerk settings, and as far as I can tell Orca should be using the printer’s default jerk (Slicer setting under Jerk(XY) Default is 0). Jerk isn’t explicitly defined anywhere in my config, but as far as I can tell it doesn’t need to be because Square Corner Velocity is.

My actual questions:

  1. Can I or should I push run current any higher with these drivers and motors to try to achieve accels I was able to with previous motors? ( Ellis recommends not going above 1.4)

  2. Is Orca using Square Corner Velocity to define jerk?

  3. My last question isn’t Klipper related, and is certainly a hardware issue, but a print defect that produces bulges on opposite sides of circular objects wasn’t resolved after replacing the motors/belts as I had hoped. Any suggestions/ideas where to look next?

    Print defect
    Print defect1266×1378 479 KB

Thanks in advance for any advice and insight!

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2

1. Raise the run current, closer to the limit will affect longevity, but as long as it’s cooled well and not triggering warnings it should be ok. Better still would be to have different stepper drivers with these specific motors.

Fan holder for stepper drivers.stl (250.5 KB)

2. Yes.

3. Good luck! (I will post here when I find the issue in case it will help anyone else down the road.)

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