PS changing my model?
I just happened to notice an odd behaviour. I basically have a round circle of extruded text. I noticed that the "Y" was not printed properly/. Like only the top level of a few layers was extruded and the rest of it was only 'a little stub' of an extrusion.
I thought that was weird and immediately went back to the model that was created with Shapr3D.
Nope, was showing there just fine. So I ran the Slice option.
What the....? PrusaSlicer, what are you doing?
This is the ONLY letter( out of 24) that it's happening to.
Anyone got an insight as to why this ONE letter is not being sliced properly?
Best Answer by Neophyl:
As I thought. Turn OFF detect thin walls. I seriously don't know why they leave that setting on by default. It causes as many issues as it 'fixes'.
With it OFF at least if a detail is missing after slicing you know its because the detail is smaller than the extrusion width. With it on it does unpredictable things.
RE: PS changing my model?
Please post a ZIPPED .3mf file. (The forum server will not attach it if it is not zipped).
Mk3S+,SL1S
RE: PS changing my model?
File attached as requested.
RE: PS changing my model?
Can I ask you a question about the 3mf file you posted. When I opened it in PS 2.4.1 it did NOT load in your profiles. It left my already loaded ones in place. This would suggest that the 3mf file has not been saved from Prusa Slicer. The thing about saving a PS project file (3mf) is that it also saves all your profiles and printer settings etc as well as the model and any modifiers. This is vital to debug any issues.
When I open your 3mf in 2.4.1 and using my normal profile settings it slices fine. This would suggest you have a setting configured that means that part of the model is not being picked up. For example what are your extrusion widths set to ?
We often ask for 3mf files, however we sometime forget that other software can output that format and what is really needed is the one saved from PS.
RE: PS changing my model?
You are right, that's the 3mf file generated by Shapr3D. I re-saved it with Prusa now.
RE: PS changing my model?
As I thought. Turn OFF detect thin walls. I seriously don't know why they leave that setting on by default. It causes as many issues as it 'fixes'.
With it OFF at least if a detail is missing after slicing you know its because the detail is smaller than the extrusion width. With it on it does unpredictable things.
RE:
Yup, the slides model looks normal now.
What I don't understand is HOW it could possible be thinking than the extrusion width? Look at the path, the nozzle make a pass down one side and up another.
Time for some learning on my end here:
So, looking at the model in Shapr3D, the 'width' of the 'y' protrusion is 0.703.
So, if I'm understanding your reply, this causes a problem because the 0.45 set extrusion width is expecting to be able to make a 0.90 track of PLA(down one side and right back up the other), and because it's less than that, it kinda gets confused?(and yet someone does it at the very end...).
Am I understanding the basics of this right? So if I scale up the model so that the 'thin parts' are always a multiple of 'extrusion width', this generally should be an issue?
What I guess I still don't understand is why is that the ONLY that letter when all the other letters have the same 0.7 witch for their 'thin parts'.
RE: PS changing my model?
The mysteries of PS. Fractions of numbers seem to play a factor, so what’s set at a certain value in your design software might not be the exact same value due to math conversion/rounding etc when it gets imported.
You see a lot of this here where an inner perimeter or gapfill on a circle or curve results in a non continuous pattern. If you break the curves of the inner and outer walls into segments as slicers do as they don’t use actual curves then because of the different radii the actual thickness changes slightly as you follow it around. When this falls into the really close to the edge for the math on if it can or can’t fit a extrusion in there then it causes the breaks.
It’s better to design it on the plus side. So if your extrusion width is 0.45 and you want 2 perimeters then making it something like 0.92 is ‘safer’ for a more predictable result.
there are guidelines in the slicer on the perimeters section with suggested wall thicknesses for different numbers of perimeters. You get a feel for it after awhile of designing/exporting and slicing.