I have been trying to print a print-in-place planetary gear without any luck. Today I found out about a setting that finally got it to print. Cura's slicing tolerance -> exclusive uses the largest part of each layer to calculate the slice which can help when trying to print something with tighter tolerances. Unfortunately, the setting doesn't appear to be in any other slicers, but maybe someone else knows another way to achieve this.
In any case, if you’re designing parts yourself, I highly recommend printing a quick test print- pegs in holes (maybe also square pegs in square holes- and maybe pair those so on square is at 45 degrees to x and y axis.)
There’s a few reasons for this. One is that holes like to be smaller than called for. Another is mechanical limits, and also… because of slicing weirdness (as thst setting above seeks to fix.)
Armed with the knowledge of how tight your printer can get with any given material, yiu can then design parametric tolerances into them.
My guess is your part was just a bit too tight and going to exclusive cleaned it up a bit- if the part had a 45 deg. Slope, and you were printing at .4mm extrusion width, you would have shrunk your part by .2
As far as I can tell, the reason that Prusa slicer doesn’t have it is that it handles the issue different with, in part, Arachne controlling extrusion width on the fly
This is one of my favorite features to introduce to people, definitely a game changer. The only thing is, when working with other people's models, I usually don't know if they've already included any additional tolerance or how much.