SKR_Pro Random issue of slow motor movements until reboot

Just got everything up and running, and so far so good on all fronts… Homing works good, and good test print of the Crown… However, I have randomly had all motion slow down to sloth speed for no understandable reason. This has happened while simply moving the gantry around with the Move Icon on the screen, and while printing of the crown… having seen the speed of motion that should occur during printing of the crown on this rig prior, and during 10mm movements per increment of the knob on the LCD screen, I would estimate that all motion slows down by a factor of 10 or so… insanely slow. The only solution I’ve found is to power cycle the SKR Pro and this instantly fixes it- printing the same file, or moving the gantry…

Any ideas??

I am running Marlin_V1CNC_SkrPro_Dual_2209_2.0.7.2_510 with the BIGTREE_TFT35_V3.0_E3.26.x.bin from this site customized to CNC only use.

The move commands may not include speed. Maybe one of the other commands (Z, perhaps), slowed it down. Try sending G1 F600 in the terminal and then see if that speeds it up.

This is probably not the solution but I had a Rambo board do something similar at one point the problem turned out to be the stepper driver chips getting to hot. If fixed it by adding a fan to the controller box.

So, I seem to have the same issue.@aventinus did you manage to find a solution?

When I boot LR2, and start moving the Y axis using the knob 10mm at each rotation, its starts moving as expected for like 50cm. Then suddenly it starts to slow down up until it barely moves.

When hitting the reset button, it immediatly runs just fine again. I can even start up a job and it runs at normal speed.

But when going back for a long distance, it starts to slow down again, and milling jobs are slow too, until… I hit reset again.

Hey Olivier, Jeffeb3 was correct- It turned out to be due to not having a speed parameter on every single movement line of either my current or previously executed GCODE file. This resulted in unexplained changes in speed like you are describing. Since making this change I haven’t had the issue since.


Thanks @Aventinus I am going to try this.
It sounds a bit strange though because I do have it on a cold boot too, but imagine it can´t hurt to change my behavior :slight_smile:

Can I ask what speed you use for general purposes?