Sliding Tolerance Test - now with mini version

thingiverse

Printers can fluctuate significantly in their tolerances, meaning how much extra space is necessary between parts designed to fit together. Ideally, this number would be zero, but unfortunately, we all have to worry about it, and what fits perfectly on my printer might be excessively loose or impossibly tight on yours. This tester will demonstrate not only the best tolerance for fitting pieces together, but also how well movable parts will slide at different gap sizes and how tightly you can force parts together (depending on strength). To use, first print both the scale holder and the insert. They're provided as one STL to make it easy to print them together and also separately if you want to test two different filaments/temperatures/extrusion rates/etc. Once the print is complete, you may wish to trim the bottom layer edges of the insert using scissors; I've beveled it in hopes of mitigating that factor so it's best to check the print and make sure. Slide the insert into the scale until it stops. The triangles on the insert will point to a value along the scale, which is your snug tolerance. By sliding it faster or more forcefully you can find the maximum tightness tolerance; at this amount of tightness your printed parts will probably fit together and never come apart. (To release the slider from this stuck position, simply pry it up at the handle.) Finally, all tolerances that slide effortlessly in this tool will move effortlessly in your final print made on the same printer using the same filament(s) and settings. As you can see from the photos, I tried this on three extruders, three different filaments, on two printers, and got very different results for all three; my Ender's tolerance with the green filament is .15mm, while my FlashForge gives .2mm and .3mm with different filaments on its two extruders. (Translucent filament is not recommended; it didn't come out great in the photo.) Not shown: the FlashForge with yellow filament gave me a reading of .15mm. A true comparison would be to run the same filament on each of the three extruders, then repeat for several other filaments, and tabulate and analyze the results. Fair warning, the full-size one is a five-hour print. I've added a mini version that's only an hour, and tried to make it easy to read.