Tolerance Tester

thingiverse

This was inspired by a tool from Maker's Muse, but 5 hours for a test seemed like too long. So, I designed a smaller one. This tolerance tester takes about 10 minutes to complete, or 8-9 minutes on higher layer heights. It is the smallest gauge that still holds up. The tolerances range from 0.10 to 0.3 mm. If you want to adjust something, you can get the Fusion 360 file here: https://a360.co/2rC0wYY. Here's how it works: The "Tol" variable sets the gap between the core and the frame. If your printer is not precise enough, the gap may be too small or overlap, causing the parts to fuse together. This will prevent rotation, so you'll need to try the file one step up. If only one layer fuses, you can usually pry it apart to free up rotation. If you find a file that rotates freely immediately without prying, that should be your default gap size when designing moving parts. ________________________________________________________ If your bed isn't perfectly level or if nozzle height is too low, you may end up with elephant foot or fused bottom layers. I added a chamfer to this one to compensate for this issue. You can also try the flat base versions if you think you have perfect level and nozzle height. If the core isn't a perfect circle at the base, then your nozzle height is probably too high and dragging filament. 0.3 mm tolerance is quite easy, and 0.15 mm tolerance is very good for most printers. 0.10 mm tolerance is much trickier and is possible with 0.10 or 0.15 layer height but I haven't had success with 0.2 layer height. ####TIP For iterative testing, a good trick to try with this is to print the first layer and stop the print and inspect. If the gap is already fused, it would fail anyway. If it's not circular, it would be a nozzle height/z-offset issue. That would only take 30 seconds or less. Start a new test and stop around 5-6 minutes right after the tab is finished. If it rotates freely, you're good to go. #### If your slicer has that option, always print external shells first to get accurate tolerances.