12 string machine heads issue

domforr

Hi, I have an old Daion 12 string from the 80's and the machine heads on the B strings seem to stick when tuning. By that I mean that you turn the peg and there's no change and then the pitch goes up (or down) by quite a bit. I can still tune the guitar but it is annoying and makes life a bit harder. I would just replace the machine heads but I can't find anything with an exact fit for the screws and I'm a bit reluctant to start drilling. Any thoughts on why it would be slipping like this? Is it definitely the machine heads, or could it be getting stuck in the nut? I've used some lubricant but it hasn't made any difference.

ICBM

It could be the heads. Are they open-gear, or have covers with two screws? If they’re either of those they can be greased. If they’re sealed cast tuners, are the key screws are too tight? The washer between the key and the body should be free to move, not trapped tightly.

By the way, never tune down to a pitch - that’s guaranteed to cause backlash in any tuner that doesn’t work absolutely perfectly (which is most of them). If the string is sharp, go well below the pitch then smoothly back up again to it.

domforr

It seems to slip whether I go up or down in pitch - but yes I try and tune up (when I remember). They're open gear. What would I use to grease them?

ICBM

domforr said:

They're open gear. What would I use to grease them?

Ordinary general-purpose automotive grease is fine. Try and get some into where the keyshaft rotates and under the gear where the post passes through the plate as well as in the gears themselves.

domforr

I've got some nut sauce (no jokes please) - would that work?

ICBM

domforr said:

I've got some nut sauce (no jokes please) - would that work?

Yes, but it's very expensive to use in the quantity you'll probably need.

domforr

Okay, great. Thanks for the tips - will see how it goes.

mart

I’d always defer to @ICBM as he has massively more experience than me, but I have to say, this sounds more like the string binding in the nut than a problem with the tuners. Try a drop of your nut sauce and see if that helps.

domforr

I have tried that and it didn't seem to make much difference. It's a brass nut, so whether it's a bit tight on those strings I'm not too sure?

ICBM

domforr said:

I have tried that and it didn't seem to make much difference. It's a brass nut, so whether it's a bit tight on those strings I'm not too sure?

It does sound like it might be. What gauge are the B strings?

domforr

It's these: https://www.amazon.co.uk/DAddario-EJ39-Phosphor-012-052-12-String/dp/B000EEL6IW

I'm tuned down to C modal at the moment, but I was having the same issue in standard tuning and DADGAD. 

ICBM

Those are very heavy for a 12-string. I'd agree with mart - probably binding in the nut.

I would be very careful about tuning them to standard anyway - that's a huge amount of strain on the guitar. 12-strings were always intended to be tuned down a tone, until much lighter string gauges became available. Personally I wouldn't tune anything heavier than 11s to standard, and even that's at the upper end.

domforr

I haven't had it in standard for some time now and I plan on keeping it tuned down to C for the foreseeable. So if the nut is the issue, how do I resolve it? File the grooves a bit? Not sure how easy that would be with a brass nut.

ICBM

domforr said:

I haven't had it in standard for some time now and I plan on keeping it tuned down to C for the foreseeable. So if the nut is the issue, how do I resolve it? File the grooves a bit? Not sure how easy that would be with a brass nut.

Yes, you will need to open out the grooves to at least .017”. Steel nut files will cut brass.

domforr

Okay thanks - not sure I feel confident enough to start filing things so may end up taking it to a luthier. 

ICBM

domforr said:

Okay thanks - not sure I feel confident enough to start filing things so may end up taking it to a luthier. 

Or use slightly lighter strings...if the 16s go into the grooves at all, 15s should be fine.