Slow travel to cancelled object on every layer

yorb commented 3 years ago

Say I'm printing two parts, A and B, and I cancel part B after a few layers. From then on, on each layer, when it gets to the end of the extrusion for part A, it does this:

An extremely slow travel move to where it would have started extrusion for part B (I would guess about 10–15 mm/s)
A series of quick travels back to part A (following the lines of where part B would have been)

This takes up time, but more importantly it allows plenty of material to ooze out during the slow travel, causing some unsightly blobs on part A (and increased risk of catching one and knocking the part).

Yes I'm using relative extrusion, Cura 4.8, Marlin 2.0.x. Is there any way to avoid this? :/

paukstelis commented 3 years ago

Please provide sample gcode. First guess is that it is related to wipe moves.

yorb commented 3 years ago

Sure, here's the file I'm printing right now that is showing the issue. I don't have Wipe Between Layers on, but Outer Wall Wipe Distance is set to 0.2 and Infill Wipe Distance is at 0.125 (both Cura defaults, I think).

SpeakerMountPartB.gcode.zip

paukstelis commented 3 years ago

It is certainly related to the wipes. Here is the first snippet:

G0 F3600 X170.223 Y128.221
G1 F1500 X173.726 Y131.724 E0.33984
G1 X173.814 Y131.812
G1 F4200 E-5
@Object SpeakerMountPartA.stl
G0 F3600 X174.435 Y132.707
G0 X174.158 Y134.191
G0 X170.975 Y149.804
G0 X170.374 Y151.187
G0 X168.36 Y167.336
G0 X168.057 Y167.308
;TYPE:WALL-INNER
G1 F4200 E5
G1 F1500 X168.332 Y167.308 E0.01886
G1 X168.331 Y167.033 E0.01219
G1 X168.279 Y157.422 E0.65931
G1 X168.295 Y151.758 E0.38855
G1 X168.528 Y151.446 E0.02671

You see that it is doing the G0 moves that are the wipe for the previous object (part B) after the @ tag for PartA. You can file a bug/request with CuraEngine, and/or remove all the wipes and just change your setup to do infill first.

paukstelis commented 3 years ago

It looks like there is some new behavior in Cura with respect to the types of movements they are also putting in NONMESH between objects on layer changes that is causing issues as well.

yorb commented 3 years ago

Oh interesting. Though, it seems like the G0 moves are part of the travel to the other part, so it kinda makes sense that they're after the tag. If I step through the actions in the Preview, it seems like those moves include all the combing moves required to get "out" of the current part and to the starting point in the next part.

So I guess what's happening is those moves to get TO the cancelled part are gone, but the moves to get BACK out of the cancelled part are still there. Doesn't really explain why it goes so slow though, does it?

paukstelis commented 3 years ago

If you look at the NONMESH object you'll see the problem. There is an F600 move. I believe if you cancel the last object in the list you'll do this F600 to the cancelled object.

paukstelis commented 3 years ago

It does seem to largely be related to combing, but also some redundant moves in the NONMESH.

yorb commented 3 years ago

Yep, you're totally right. Thanks for figuring that out so quickly! I might experiment with turning combing off, though it does seem to help quite a bit and I rarely need to cancel objects... but when I do, it sure is a lifesaver. 😅