Extreme Vibration/Stutter on 'curves' on CoreXY

Adam - V3D

Been trying various tests today on my Ratrig V-Core 3 CoreXY before running upgrades.

I noticed previously that i'm getting ringing, but it seems to be a little different than normal.

Today i ran a large circle print in an attempt to keep speeds consistently high when printing and it resulted in quite extreme vibration. I don't think its resonance, i think it's the stepper configuration that is starting/stopping extremely quickly as it attempts the 'curve'.

My first assumption is that there is a gap in my knowledge regarding how jerk is working in RRF so this seems like the obvious place to start, but I felt it might be good to post here to get some more experienced eyes on it.

Video of the vibration, mostly just noise here: https://youtu.be/hF_Fqjp0yzM

Config.g file here: config.g

Images in dropbox link below. (was having issues with phot upload) (this was a flow rate test, so the change in speed and poor extrusion is deliberate.) Video is from this print. Also images of a second print with modified settings that extruded ok, but still had incredible vibration. Config file is from this print.
https://www.dropbox.com/t/M2cLLJ43HtjYIk4w

Print Gcode from prusa slicer: Single Wall Flow Rate Test v3_0.3mm_PLA_MK3S_22m.gcode

Appreciate any assistance. Thanks.

Phaedrux

Indeed your jerk values are very low

M566 X250.00 Y250.00 Z6.00 E120.00 P1

Try this instead

M566 X900 Y900 Z60 E3000 P1

Keep in mind that these values are in mm/min

Adam - V3D

@phaedrux Printing with new settings now. If those work better, the ones I had were WAY off.

Adam - V3D

@phaedrux Vast improvement. https://www.dropbox.com/s/rq4xs21e7av3cp6/2021-08-08 19.11.58.jpg?dl=0

Seems like the biggest issue was perhaps that E was set about 10x lower than it should be. I guess the print was slowing down to allow the E axis to meet its minimum corner speed and then very quickly accelerating back up, causing the vibration.

Phaedrux

Yes it could be the extruder, though your X and Y were quite low as well, so the segments of the curve have a direction change that could also be causing acceleration to come into play. The low Z jerk could also be causing the same problem if you have mesh compensation active and it has to slow down X Y movement to allow the Z axis to move up and down to follow the mesh.

Adam - V3D

@phaedrux Ye, just problematic all round then. Thanks very much for the assistance