Finished my mouse shell design, internals are finally in

I had a similar ordeal last year when I designed a custom bracket for my tool bench. It seemed simple, just a mounting block, but the clearance issues turned out to be surprisingly complex. I was working on a simple bracket for a shop light, maybe 100 millimeters long, and the tolerances I initially set were too tight. When I ran the slicing software, it imediately showed that the interlocking pieces weren't closing. I spent an afternoon adjusting the clearances, moving from a 0.2 millimeter gap to something closer to 0.4 millimeters, wich was the real fix. It sounds like the scale of the problem is what gets you, rather than the geometry itself. I was using Fusion 360 for my work, and the parametric nature made it easy to just shift that clearance everywhere at once.

My biggest lesson was how much time I wasted on surface finishing before checking the assembly. My initial design looked smooth in the CAD enviornment, but when the first test print came off the filament, I realized the internal volume was just a messy jumble of overlapping faces. It's funny how those sketches look so clean when you are only looking at them digitally. You have to print small parts, test the assembly, and then go back to the computer to refine the negative space. My bench bracket was a success after three failed attempts, mostly due to simply increasing the gap between the two main attachment points.

Keep up the design work. Those parametric tools are great for iterating thru revisions without having to restart the whole project.

I found myself running into similar problems, but my headache was less about the geometry and more about the actual slicing. When I tried to print my own custom controller shell, I struggled with the thin walls and internal mounting clips. My first several attempts failed because the PLA was just too brittle under stress. I switched to using PETG for the print because the layer adhesion felt a lot more reliable when I actually started testing the button press. The most tedious part was definitly the printer calibration itself. I had to spend hours tweaking the retraction settings to get those delicate internal features to come out without rounding off at the edges. I learned that orientation makes a massive difference for those pieces with small features. For my shell, printing it upside down so the clips faced upward, supported the design much better than trying to print it laying flat. It meant I didn't have to worry about the clip breaking off during support removal. My failures ussually came down to insufficient overhang compensation in the slicer settings. It took me three full failed print beds to finally get a shell that felt solid enought to put a PCB inside without worrying about it cracking when I pressed the triggers. It wasn't the design complexity that got me, but the material behavior during extrusion.

Nice to see someone still walking the feature tree instead of hacking at it like we used to. Back when I started we drew everything on paper first, then cut foam blocks with a knife to check how a shape sat in the hand. Took weeks to test what you can now revise in an afternoon.

One thing I'll say about that first print, don't sweat it if the fit is snug. A few passes with a needle file or some sandpaper wrapped around a dowel fixes most tight spots faster than another print cycle. I'd plan on printing the button caps a couple times anyway before you commit.