Stall detection fails after calibrating steps/mm
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Hello! I have been doing some calibrations on my CoreXY printer and I have ran into some issues with my sensorless homing setup.
I simply can't get the stall detection to work after changing the steps/mm on each motor for X and Y.
I used this before the calibration:
M92 X80.00 Y80.00 Z400.00 E2771.50
And changed it to this:
M92 X79.24 Y79.64 Z400.00 E2771.50
Stall detection settings:
M915 X Y S3 F0 H300 R0
The stall detection works perfect with 80 steps/mm but with the lower ones(79.**) does not make the stall detection trigger at all. I have tried to change up the S parameter all the way down to -50 but there are no visible changes. The motors drag the extruder to the end of its axis and the belts start slipping.
I can't find anything about this in the limitations section of stall detection. Is there anything im missing here?
Thanks!
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What speed do you use in the homing move? How does the minimum speed for stall detection reported by M915 compare with that speed?
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@dc42 Im running it on 3600.
My homing file looks like this:
; homeall.g ; called to home all axes ; M400 ; make sure everything has stopped before we make changes M913 X50 Y50 ; reduce motor current to 50% to prevent belts slipping G91 ; use relative positioning G1 S1 X-400 F3600 ; move back 400mm, stopping at the endstop G1 X5 ; move away from home G1 S1 Y-400 F3600 ; move back 400mm, stopping at the endstop G1 Y5 ; move away from home G1 S1 X-400 F3600 ; move towards axis minimum G1 S1 Y-400 F3600 ; move towards axis minimum G1 X5 Y60 ; move away from home G92 X0 Y0 ; set coordinates to 0,0 M400 ; make sure everything has stopped before we reset the motor currents M913 X100 Y100 ; motor currents back to normal ;G90 ; absolute positioning ;G1 X0 Y60 F6000 ; go to first bed probe point and home Z ;G30 ; home Z by probing the bed
M915 reports:
M915 Driver 0: stall threshold 3, filter off, steps/sec 300, coolstep 0, action: none Driver 1: stall threshold 3, filter off, steps/sec 300, coolstep 0, action: none Driver 2: stall threshold 1, filter off, steps/sec 200, coolstep 0, action: none Driver 3: stall threshold 1, filter off, steps/sec 200, coolstep 0, action: none Driver 4: stall threshold 1, filter off, steps/sec 200, coolstep 0, action: none
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You are running older firmware, so M915 is not translating the full steps/sec into mm/sec. However, we can do that by hand. Assuming you are using x16 microstepping, 300 full steps/sec is 4800 microsteps/sec, divided by 80 steps/mm is 60 mm/sec, times 60 is 3600 mm/min. So your homing speed is exactly the same as the minimum stall detection speed. When you reduce the steps/mm, the minimum stall detection speed is slightly higher than your homing speed.
So you need to reduce the M915 H parameter.
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@dc42 I will update the firmware right away. Been a while sinse I updated last.
Thanks alot for the explanation. You were 100% right! I was a bit too quick to overlook that
It triggered right away when I reduced the H parameter.
Thanks again