Knob turns, shaft doesn't

[Tighthead]

Happened just tonight as I was tuning up. The tuner knob on one of my A course strings turns, but the shaft doesn't--or I should say that the shaft WILL turn, but not in the direction I need it to. I can loosen the string to my heart's content, but I can't tighten it.

I took a look at Paul Hostetter's instructions for reviving and maintaining old tuners, but I don't think it addresses this problem.

Any suggestions for a fix? Seems like just a loose tuning knob, but I'll confess that I haven't a clue as to how to tighten it.

Thanks a lot...I'm really enjoying this mandolin, and I want to get back to playing it!

--Milan

[markishandsome]

Do the knobs have little screws holding them on? Do you know what brand of tuners?

I had a set of Schaller's (non-screw-on) that had a couple loose knobs. So loose in fact I could yank em right of and then superglue them back on. Aint loose no more.

[billhay4]

mark's solution is probably best. Yank them off and superglue back on.
Bill

[Tighthead]

They are these kind...I can just yank them off without damaging them?

[8ch(pl)]

if you can't, Superglue may work itself into the hole. Clean the area with a bit of alcohol, mask the shaft with tape, the button too if you want and apply a drop or 2 of glue. Let it set for a bit and see if it holds.

[MikeEdgerton]

I might be tempted to touch the shaft of the tuner with a soldering iron and pull gently on the button. It should come off. Then I would use CA to glue it back on. Be careful not to fill the hole entirely as the glue will spurt out and whatever you do don't do it while the tuners are on the mandolin.

[markishandsome]

If they're loose (ie not turning the shafts) then you can probably just work them off manually. The plastic is pretty hard, but I would use my fingers and not pliers. Very little superglue is needed, don't use Gorilla glue.

[Rick Turner]

Please be careful with superglue. Any dropped or splashed on the finish will just become a permanent blotch. Use the micro-pipettes from LMI or transfer just a drop using a toothpick. DO NOT attempt to mask the tuner buttons or shafts as all you'll do is superglue the masking tape to the mando parts if you're depending on masking for a clean job. This has to be done quickly, surely, and you should be ready to wick up any excess glue immediately once the glue penetrates into the hole in the tuner button. Get in clean, get out clean, and you'll be fine.

[mandroid]

Wouldn't taking the tuners off the mandolin, first, be a good precaution?

the connection between plate and the shaft journals benefited from a
little bit of percussion to tighten them up.
made a concave punch , put it in the vise, so curved end of journal [hole] wasn't flattened against the shaft.

[markishandsome]

Huh?

[jk245]

Try to pull them off by using a fork as a pull bar, then do the gluing using any appropriate glue (small amount of epoxy, CA, etc.) Do not 'pry' as you might dent the wood. It might be a two person operation.

[Tighthead]

It actually came off pretty easily...a drop of CA and I let it sit for awhile. It seems to be holding, but I'm a little skeptical that it will last.

Anyway, thanks a lot for the advice, I'm back to playing!

--Milan

[mandroid]

Mark, sorry for the confusion , common machinery terms are so 20th century.
bearings on shafts are held in journals , bearing blocks,
bolted to something,
in this case its just a small piece of metal with a hole in it, self riveted thru a square hole the baseplate.
the mechanical connection can weaken , re setting the 'rivet' fixed mine, fine.

[newer schaller,and such, die cast the whole base/thing in one piece,
then the worm gear lays in a slot from the bottom, round gear holds the whole thing together.