Poor man's gear box for post processing 3D prints

thingiverse

For smoothing and polishing 3D printed plastic components, high-speed "dremel-style" tools can barely be used at 10,000 rpm. I created a makeshift gearbox that reduces speed by a factor of six or so. It fits with the "Cotech" brand (found in Sweden at "Clas Ohlson" stores, equivalent tools exist under other brand names) with an additional bit chuck and an extra flexible extender. Using it, I can easily sand, cut using diamond tools, and polish the items without overheating the plastic. However, use caution and ensure proper assembly of the parts. I couldn't resist using the attractive "Gear Bearing" by Emmet (from 2013, please see https://www.thingiverse.com/thing:53451 for the original item) when designing this item. Please note that the small pin (white in the picture with the gearbox partially disassembled) secures the chuck to the main part. The large cogwheel then locks the pin, and the red top finally locks the large cogwheel.