I talked to Mama Sperzel and she informed me that the thumbwheel isnt supposed to come out of the machinegear on Sperzels cause its a "flanged-end"(not the right term , but i forgot excatly the term she told me) mechanism and youll notice now that the gear wont tighten down properly. It will tighten though. I always manage to unscrew that thumbwhell too far and I have about three tuners now that have had the "flange" busted.