I believe your talking about the Axe CP.
Vito at this point if I were you I'd cut my losses, and get a new feathering shaft (unless you can get the broken screw out) and replace the phillips head screws with 2mm x 6 cap screws. Cap screws are stronger and make changing blade grips easier. Anyway the screws are normal threads. The reason one broke is someone went overboard with loctite and there kinda weak. The only downside with capscrews is the higher profile head doesn't let the blades fold forward for storage, but one of the guys on RC Groups is working on getting allen head screws that are both stronger and will allow the blades to fold both ways. Hope this helps.