Suggestions, setting first move travel speed and accel

General Discussion
1

Hi,
I have been tuning my accels, and it seems the TMC driver is doing some kind of internal tuning on the first move. I get TMC ‘stepper_x’ reports error: DRV_STATUS: 001f6000 s2vsb=1 stealth=1 csactual=31 many times. I am running stealthchop on TMC5160’s, I have 2 steppers in parallel on a single TMC5160 for the x axis. It fails on the first move, makes a clunk etc or throws this error, accel is only 4000 and I have input shaper. I’ve increased currents, and doesn’t seem to help. The rest of the print proceeds just fine.

I want to write a macro that sets the travel speed and or acceleration for the first move, or maybe first layer, to something different than the rest of the print. I don’t really want to have this be slicer dependent, so ideally it would be handled in Klipper behind the scenes.

Perhaps I could intercept the first G0 or G1 command, and reassign the speed to something much smaller and then after that move change the accel? I wish it could be a part of the START_PRINT macro, but I need the first move to come from the gcode file, and then do something after that first move. Any suggestions?

2

Seen this? New TMC docs: don't use hold_current; avoid interpolate by KevinOConnor · Pull Request #4977 · Klipper3d/klipper · GitHub

3

wow, very interesting! I might have to go back to spreadcycle. My SKR Pro can handle high microstepping with 0 for step pulse and 0.9 deg steppers, so I should be ok there, but will have to adjust currents all over.

PS, I think we used to chat over on the cultivate3d forum, I have a Beast V2, but now mostly printing on an FT6.

Thanks for the tip!!