Hi, I’m new in here this is my model after print, as look in other layer it maybe good (not sure) but there is a small gap when it build up (picture 1) as I measure it same layer (pic 3, 4). Is there anyway to fix that gap.
I try some change about infill/wall overlap: 15%, wall to 4 but it still same issue
I try search ethernet some one said it cause by the layer time (which I not understand)
My printer:
A1
Nozzle: 0.4mm
My setup:
Filament: PETG - Bambu Basic - Yellow
Temp: 230
That looks like the classic warping caused by the internal flat plane.
Like everything, that plane shrinks as it cools. Since it’s solid, not an infill pattern, it shrinks with extremely high forces. Because it’s a significant proportion of the width/length of the model, the small percent shrinkage pulls the sides inwards by a small fraction of a millimetre. The next layers print as normal, without that shrinkage, so you’re left with a tiny step in the outer wall. Often you’ll notice that the extreme edges of the bottom layer are also pulled away from the build plate, as the sides are pulled inwards.
I’ve had excellent results by adding an internal hidden “ring” slot cutout, running from a few layers off the bottom to just above the height of the internal flat plane. When the inner plane shrinks, it still pulls inwards, but the hidden slot means that the pull doesn’t apply to the outer wall. The next layers print on top normally, closing and hiding the slot.
The slot can be very narrow, but needs to be wide enough for the slicer to recognise it. It needs to start fairly close to the build plate, perhaps two or three layers up, so that it properly isolates the warping forces from the outside walls.
Here’s a cross-section of a cylindrical “tin” I designed. You can just see the slots near the outside edges of the base and lid. The slots start on the third layer and continue until just above the inner solid planes. This eliminates the warping seen on the outside (which occurs even with those big internal fillets!).
