I’ve got a part that is shifting in the back of it starting at the top surface after supports and I have not found the cause yet.
the paths all look correct in Bambu Studio when reviewing the slices
when I print a smaller portion of the part the shifting is less severe
the shifting is occurring on the inside and outside of the part
does not appear to be related to wether I use a support interface or not
when printing the full part the shift is about 2mm
To troubleshoot I am re-printing the same smaller cut of the part and trying different settings and layer heights
Here are some screenshots showing the issue. I was going to let it slide but since it is also shifting the inside as well, I can’t slide in my other parts that need to fasten to the inside.
Doesnt look like a layer shift to me. Shifts are the same direction on both sides of the wall. Looks like a benchy hull line. As a guess, is that large flat surface being printed on the underside of that tray - is that the same layer number? Check in slice preview and Layer Time. If so, that one layer is probably taking a ton longer than the rest, so it is going to cool unevenly from the rest, and this is what you get.
This is a huge rabbit hole, but for such a large part you may have better luck with chamber heat, as well as normal speed troubleshooting to get the layers more even in printing time
It is shifting in the same direction on both sides. In the underside photo the arrow is pointing at the section that is shifting outward in the same spot that is shifting outward on the outside of the part.
Yes the underside is the same layer and I agree that could create a seam right at that spot but then why does the remaining part of the back of the print stay offset all the way to the end of the print?
I think you are right though it probably has to do with the cooling. Do you think rotating the part 180 so the back is in the front would change anything?
OK, so you got me thinking and I found out what is going on. the top part is actually correct and its the bottom of the part where the problem is and it is tapering inwards.
This is PLA and the chamber temp is turned off.
I will also turn off the AUX fan and try it and I will rotate the part 180.
Not sponsored or even verified, but the new Qidi printers are making some claims that adding chamber heat to even PLA can help get more accurate parts out of these cooling scenarios. Perhaps the H2 can help you there as well but I’m not sure the exact parameters to try. I bet it’s VERY touchy and needs to be low, given PLA’s low glass temp. Maybe someone else w/ the hardware can chime in if this is a good idea.
Yeah this is tough the part takes 1 day and 5 hours to print at normal speed and 24 hours in turbo so it takes a day to find out if you changes made a difference.
I am trying again now this time ive rotated the part 180 and I am turn gin off the AUX fan.
The part is as wide as the build plate and moslty support underneath so its a tough one.
Wenn du Filament sparen möchtest und schnellere Ergebnisse sehen willst, dann benutze das Schneidwerkzeug im Bambu Studio, um ein kleines Stück wo der sogenannte layer shift sitzt auszuschneiden und deine Einstellungen an dem kleineren Objekt zu testen.
Ja, genau das habe ich auf dem Foto unten rechts gemacht. Es ist nicht so stark, aber es ist leicht vorhanden. Man muss das ganze Teil drucken, damit es auftritt. Das deutet meiner Meinung nach eindeutig auf ein Problem mit der Bauteilkühlung bei großen Drucken hin.
Well I’m 20 hours in on this one and it’s still got the tapering issue and the back bottom corners slightly lifting. Bummer I may have to just live with jjit. This one has both the exhaust and aux fans off. Chamber steady at 42c, part cooling at 20%
it is always in the same just like in the video but dang this is a brand new H2S and these are my very first prints and it is only occurring when i print the whole part it hardly occurs when i slice the part down and print only the failing section.
If you want to go nuclear on it, try a CF or GF impregnated filament, and print this in it. The fibers primary goal is to resist warping and they do well. This is a real big part.
I never could resolve the protruding at the top layer in back. It must be just because theres so much support material. But I finished the project and made a video if anyone wants to see the final outcome:
