Stripped tuning machine?

[Tash]

Is it possible to strip the internal gears of a tuning machine? One of mine appears to have done just that. I was trying to tune the string and just couldn't get the last 1/2 step for some reason. Then I noticed the pitch was slowly slipping DOWN without me touching the tuning machine...after unstringing that string I found that turning the head no longer moves the string winding peg, and that you can turn the peg by hand.

Obviously this renders the machine useless. Is there a way to fix this or do I have to buy a new tuning machine?

 

[andysvec]

I had that happen on my modulus at a gig not too long ago. I didn't see any way of taking apart the tuner so I just bought another. But the same thing happened, I was turning it and it would go a little, then loose tension.

 

[Hambone]

No, it isn't possible to actually "strip" a gear tooth in these machines by physical force unless the metal was poorly cast in the first place. If it did then the one missing tooth is keeping the worm gear from engaging the next tooth. What is more likely to have occured is the flat sides of the peg shaft have rounded off or the recess in the spur gear has rounded so the gear is spinning on the end of the shaft. The peg is a white metal and is soft so it isn't too unusual for it to give up on occasion. The gear itself is brass and that's pretty soft too. Another possible is for the brass spur gear to have worn such that it allows the edge of the worm gear to suage itself into the edge of a tooth of the spur gear. The spur gear is machined so that this surface is already a little bit cupped and if the edge of the worm gear gets stuck in there, it won't be able to turn anything. The worm gear and it's shaft are steel so it can really trash the brass spur gear it the spur gets too worn.

Bottom line - get a new tuner or a new set.

 

[Tash]

I ordered a new tunner this morning.