Weird thread printing issue
Designed a little screw tin in FreeCAD. The bottom piece printed the male threads fine, or lets say good enough. But the top piece with female threads just won't print for me. I'm getting what seems to be the PETG filament is not sticking to the thread, or it's detaching. It is a 2mm thread, so it should print fine with 0.2mm layers.
Loose filament strands
If someone could offer some suggestions, I'd appreciate it. Not sure why this print is failing, when the print with male threads worked fine. This is the first time I've seen this phenomena.
RE: Weird thread printing issue
Can you check in your own slicer whether the toolpath resembles the actual print (incorrect) or the expected "large circle spinning around a small circle" when moving through layers?
I've had days where weird issues disappeared on restarting the slicer, and of course the failure mode could not show for anybody else.
There is a parameter "slice resolution" with an obscure default setting at 0 value that would hypothetically cause similar symptoms if incorrect (the loaded file shows "0" default for me).
RE: Weird thread printing issue
Tool path in slicer looks normal. No funny cutting corners. I've never even touched the slice resolution. What's odd was both parts, the male and female were sliced at the same time. The male part printed ok. But the female didn't and hasn't printed correctly four times.
RE: Weird thread printing issue
I heard the filament make a noise, perhaps it is cracking off. Of course if the filament delaminates, then there's no place for the next layer to go. I've kept the PETG in desiccant, and print direct from a PrintDry unit. Maybe it's a bad spool.
Or it's the slicer, I have no idea. I'm baffled.
RE: Weird thread printing issue
Even printing direct from USB causes the strands to separate from the thread. Then they pull tight. Surely this has to be printable. I have printed hotter, colder, more flow, no volumetric limiting, yes volumetric limiting. Oh tried a different spool of PETG, but still Overture. Different color. Still get the strands. The female 2mm pitch threads are unusable. Wish I knew why.
I attempted to reduce the fan, but it didn't sound like it was obeying. It was at 21%. I changed it to 5% and there was no apparent change. I did get some kind of clue. When I plugged in the USB stick, it said I had old firmware and had to adjust the fans! So I guess I need to look at that. Wild card though...
RE: Weird thread printing issue
I changed the model file, and most of the issues went away. Don't understand why, the changes were imperceptible. Like the divot radius was changed by 0.5mm, and the thread was increased from 69mm to 69.125mm. The female thread printed, with absolutely normal settings. Only took 7 tries, at 1 hour per try. What a waste of time. A little lubricant and the lid just screwed on to the bottom piece. I don't know why there's those annoying lines at the boundary, that's at 4mm where the part changes from the filled base, in both parts.
