Ball bearing bottle cap

thingiverse

I store ball bearings in old medicine bottles. Over-the-counter medicines like antihistamines and acid reducers are commonly packaged in these bottles in the US. Three-dimensional printed caps make it easy to dispense loose bearings of various sizes. Each cap has a small hole in the center, and its size is engraved on it. I provide STL files for common loose ball bearing sizes used in bicycle repair and other sports/hobbies. Sizes include 3/32", 1/8", 5/32", 3/16", 7/32", and 1/4". To use these caps, press them into the mouth of a medicine bottle where a small hole allows only two or three bearings to be dispensed at once. If the fit is too tight, enlarge the plastic bottle opening by carefully filing its inside edge. The cap needs to fit tightly so that it doesn't pop out when dispensing bearings. For safe storage, the original medicine bottle lid fits over the top of the dispensing cap. I label each cap with a sharpie marker and write the bearing size on the bottle lid as well.