Tolerance of parts that should just tightly "snap" together
Hi,
I'm trying to print this: https://www.thingiverse.com/thing:4699856/files
I started with the sides.stl, printed 3 of these with 0.2mm PLA settings.
The video states that these parts should just snap into each other with the added insets on the sides. I tried it, it is just loose.
I like to think, that the prusa prints too "exact" 🙂 and that the tolerance the designer had used for the snapping insets and extrusions is too high.
I had the same problem with this https://www.prusaprinters.org/prints/49460-raspberry-pi-zero-case design, that the parts didn't hold together well enough.
Is there any setting in the prusa slicer to make these parts snap better together, or is the only way to edit the stl/blend file for better results?
Thank you.
The blender files are included so it should be possible to tweak the tolerances, or the structure is simple enough that a complete redesign shouldn't take long - the designer has a No Derivatives licence but reinventing the cube is probably OK; there is a remix posted (which might print better..?) so he doesn't seem to worry about the physical structure.
I had the same problem with ...
We are seeing a lot of poorly tested designs since the reward system was announced, they used to stay on Thingiverse...
It's not really a slicer issue, if you start changing the settings you are likely to cause more problems down the line. Luckily there are plenty of other Pi0 cases to try.
Cheerio,
RE: Tolerance of parts that should just tightly "snap" together
Getting snap-fits right is hard—what is loose for you may be too tight for someone else. Sometimes the simplest fix is to scale the model up or down by 0.1 or 0.2%. Should be okay for this model but may not work for something like a Pi case because of course the whole model will be slightly larger or smaller so the board may not fit anymore.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Tolerance of parts that should just tightly "snap" together
If every fitting part on a model is loose on your setup you can also choose to slightly over extrude. Basically set up a new filament profile with it configured that way and it will push out a bit more plastic.
I did my Dune shield generator design and for me on my Mk3 it fitted together perfectly but for one member of the RPF who tried it they had to sand things a tiny bit to get the fit so I don't think there is any simple answer to this. Every designer generally tolerances their designs for their printer. You sort of have to if you even bother doing test prints. Which as Diem points out a decent designer will do. It doesn't help all the other printers out there though unless you also include a tolerance model I suppose. That way you could tune with the simple part and have 'some' hope of success with the main more complicated model.
Ah the joys of 3d printing 🙂
RE: Tolerance of parts that should just tightly "snap" together
Google for "crush ribs"
RE: Tolerance of parts that should just tightly "snap" together
You may also want to google "Snap-fit" and click on images.
The Filament Whisperer
RE: Tolerance of parts that should just tightly "snap" together
Thank you for all your answers. A lot to think about.
It seems there is no easy fix (besides of just using glue) and a bit of experimenting. But that's the joy in it, I think :-).
I'll think about reinventing the cube, maybe it is even possible to print it as one, avoiding the snapping issue completely (and generating heaps of others :-))