Cube with pointy corners - PETG
I am Testprinting a cube 60 x 60 x 20 for testing of warping.
Warping on bed is solved.
Temperature raise in te chamber and hotter first layer.
But, have a problem on the corders, which don't touch the bed.
They get pointy.
Have tried a different infills, gyroid and cube, have tried 40 - 15%.
MaxVolSpeed from 20 - 25, the pics is 25 mm/s MVS no difference.
Speed from 100-140, it does not make much difference.
Filament is very dry.
I think myself it is a temp issue, the outside shrinks to inside and the corners not.
This is why I tried less % infill and different infills.
I hope you can help me here.
Just a guy with a Core One L on a 3D Journey
RE: Cube with pointy corners - PETG
For something like this, changing the infill won't really help. The corners are curling due to thermal contraction. Also, need to be careful with PETG and raising the chamber temp, this not only compounds the problem but could cause partial nozzle clogs.
I would suggest having chamber temperature off, increase perimeter cooling and raise the minimum layer time. If you attach your 3MF project file (you'll need to zip it first) I can tweak the parameters for you.
RE: Cube with pointy corners - PETG
I have the idea this comes from the change in speed between corner (almost zero) to the walls.
The difference in heat injected in the surface is of a different level.
I tested on the plater of prusaslicer, and there it shows really if I slice and check the speed.
Have tried already more cooling, 30-60%, tried cooling from lower layers (after 1 layer print fan / cooling on), print with open door of the case, average temp is around 32 celcius, tried higher and lower bed temps.
Now when I really slow down perimeter speed, to 30mm/s of all perimeter settings, it is showing that the speed difference between walls and corner almost is equal.
I am testing it now.
I will upload my 3MF @hyier, thanks a lot you like to look into it. See attachment
30 mm/s corners almost equal speed
perimeters on 80mm/s big difference in speed.
Just a guy with a Core One L on a 3D Journey
RE: Cube with pointy corners - PETG
Well I have tried much slower, also slower acceleration, to even the heat out of the corner but it made it worse.
Slower with fast acceleration made it better, but still not gone.
Attached the 3MF
Hope you have some ideas @hyiger
Just a guy with a Core One L on a 3D Journey
RE: Cube with pointy corners - PETG
Well I have tried much slower, also slower acceleration, to even the heat out of the corner but it made it worse.
Slower with fast acceleration made it better, but still not gone.
Attached the 3MF
Hope you have some ideas @hyiger
I'll take a look later today after work (in around 6 hrs)
RE: Cube with pointy corners - PETG
Thanks, I will be sleeping then, so see it tomorrow.
I just made another testprint, with higher speeds, and even the first layer, the corners already have this problem.
Can it not be that there is overextrusion on the corners? The print head goes slower there and might overextrude there if it keeps up the same extrusion flow as on the straight and higher speed parts.
So it pushes the filament out and it looks pointy because of it?
I mean the contraction should not be a problem at the first layer yet right?
Just a guy with a Core One L on a 3D Journey