Bug report: object cancellation causes ugly things to happen

[gnydick]

I have 3.5-rc2 with tool distribution board and tool boards on Core XY

When I cancel an object with M486 C, the XY motors make a horrible GAAAAHHNKKKKKK sound and the gantry is flung a short distance.

It makes that sound every time it skips an object.

The position is lost as steps are obviously messed up.

Then, after homing and resuming, the same thing happens with every skipped object.

[oliof]

@gnydick are you saying it happens whenever you emit the gcodes to skip another object, or whenever an already marked-to-skip object is being skipped? I assume the latter but just want to make sure.

[gnydick]

@oliof the latter, since when you emit the code, it will immediately do the skip.

[mballin]

@gnydick Any update on this, i want to use the object cancel plug in, i tried it, and now it really messes up the print, and changes the axis for what the printer is calibrated to.

[dc42]

@gnydick is this still an issue with 3.5.3 and/or 3.6.0-beta.1 ?

[gnydick]

@dc42 Don't know, I'm not doing it because it nearly caused my printer to self destruct.

[dc42]

@gnydick have you checked that the maximum speeds you have set using M203 aren't higher than your printer can manage?

[Tinchus]

@dc42 I think not on 3.5.3, wich I have. I have cancelled objects and it works ok (duet3, 3.5.3, SBC mode)

[gnydick]

@dc42 definitely. My printer never loses steps when used normally.

[dc42]

@gnydick is that the case even if you request very high speeds, e.g. G1 X150 Y150 F100000 ? I think RRF uses the maximum speed you have configured in M203 when doing moves to skip objects.

[gnydick]

@dc42 yes, it is the case. I've used cancellation in the past without issue so I think this is a regression.