what does “tumbling” do to affect grinds of a yoyo? how does string theory tumble a yoyo?
To tumble a material is to put it into a tumbler. Tumblers are basically a big metal can with big rocks in it and it just rolls and shakes to cause the rocks to roll around with the parts. It removes minor imperfections and produces a smooth machined texture to the material. As for grinds I would say it would be similar to, only an alternative of, beadblasting without the rough-ish finish.
String Theory seem to be very innovative, With their finish and the choice of a custom bearing.
I will have to get one.