As a first cut, here's two ideas: - AliExpress/Alibaba/Taobao instead of Digikey - tear down a mass produced product that has approximately the right size of

As a first cut, here's two ideas: - AliExpress/Alibaba/Taobao instead of Digikey - tear down a mass produced product that has approximately the right size of part that you're looking for and see what you can find. If you're super lucky there'll be a generic part number on the item that you can use to do some research with. If you're less lucky, take some measurements (dimensions, RPM, torque, voltage, current, wavelength, whatever) and start looking around to see if there are manufacturers making generic versions of that part.