X/Y shift after material change mid print

[CTotten 18]

I was trying to use up some left-over materials (like 2-5m of filament left on spools) by taking advantage of the material feed detection on the S5.  It seemed to be working well, but after the second material change, I noticed an X/Y shift in the print.  My assumption is that I somehow bumped the print head in the process of changing materials.

 

My question:  Is there a way to re-zero the X/Y position of the print head after changing material mid-print, before resuming the print job?  The print head parks in the front / middle position to change the material, then immediately resumes the print job after the material change.  What I am hoping you can do is somehow command the print head to return to the home (back / left position) to validate it's X/Y position before resuming the print job.  I think that would prevent this issue, because my thinking is that my bumping the print head (cleaning off a couple of globs stuck to the nozzle) introduced a small bias into the X/Y position the print head thought is was at, then caused the X/Y shift when print resumed.  My understanding is that the print head position is not dynamically measured, but is based on change commands from the known "zero" position.

[gr5 2,094]

It's called the home position.  That's crazy that it doesn't re-home.  Please report this as a bug to your reseller who will report it to their distributor who will report it back to Ultimaker (sigh).

 

 

[CTotten 18]

1 minute ago, gr5 said:

It's called the home position.  That's crazy that it doesn't re-home.  Please report this as a bug to your reseller who will report it to their distributor who will report it back to Ultimaker (sigh).

 

 

Is it supposed to re-home after a material change mid-print?  It makes sense to me that you would do that, but I didn't write the code...

 

And is that really the "formal" way to report a bug to Ultimaker?  Don't they monitor this forum?

[gr5 2,094]

Actually for software issues the best way is to report it in github.  But the UM3 and S5 firmware, although you can get the source code easily enough, is not on github (at least publicly) so there is no place to report firmware issues on github.

 

Lots of cura software guys are on this forum but I haven't noticed any firmware people.

 

It used to be that this kind of thing was fixed in the next release.  Now it can take years.  I guess I recommend you just don't bump the print head.  It's easy to change the filament without ever touching the print head.

 

Also be aware that *typically* the servos turn off automatically after a certain amount of time (30 seconds?  60 seconds?) so maybe if you bump the head in the first 30 seconds it's fine but then they power down.  Not sure.  Or maybe you have to bump the head really hard (assuming servo power is still on).

 

Now that I think about it more, the Z stepper must be powered during this time or the S5 platform would fall down.  So that implies the X and Y servos are also engaged.  So you must have hit the print head really hard to cause this problem.  I suspect.

 

 

[fbrc8-erin 269]

The printhead should move to the front middle during material change in the middle of a print and the motors lock in place.

 

Normally if I've got a shift on the print after material change during print it's usually that the build plate got knocked slightly rather than the printhead.