The Les Paul Forum

I'm a pretty sharp tech and i can promise you, it's never the tuners.
Locking tuners are great for heavy giggers who want to facilitate string changes.
It's always the nut.
I angle the slots towards the tuner and cut the slots .002"-.005" larger than the string. This is critical.
If your slots are cut to the same width as the string, it will bind.

And...everybody does a couple mid-set touchups.
Its the rare guitar that will stay in tune for a set.
Especially if there are hot lights.

Also, nut slots should be cut so 1/2 the diameter of the string sits proud of the slot.
Minimal wraps on the tuner post.
3 max.

Hi Charlie, Thanks immensely for the insights. I've had the nut slotted with rounded slots so that the strings would lead towards the peg head and not have a sharp angle at the headstock side of the nut. Mouradian's in Boston recommended this and did the work. I don't get any "pings" during tunings so I think the slot size is OK but I will have to check with calipers to get exact.

I do minimal wraps on the string post (per Joe Bonamassa's guitar tech). I have Schaller tuners and have for years suspected them to be the problem. Fellow musicians have had Les Paul tuning problems and switched to locking tuners however they had a different tuner footprint than mine. You indicate that "1/2 the diameter of the string sits proud of the slot."

Do you mean that the slot depth should be no more than 1/2 the diameter of the string? My slot depth is deeper than 1/2 the string's diameter. As I mentioned, the slot is curved so that the string's path is "guided" towards the tuning peg. This eliminates the abrupt pointed side angle at which the string comes off the nut towards the peg.

Yes. Limit slot depth to 1/2 string diameter.
Polish slots with a few passes of 600 paper and a thin rag with polish.
I like Brasso.
Slack strings and check for wiggle room at the nut.
Good luthiers can be to fussy to leave the necessary "slop"

Do you have other guitars that stay in tune better?