HAAALP with lowered tunings

[Eagle]

Ok several things;
The stop tail is too low for the tunamatic.
The nut is just black plastic and can cause issues.
The Tuners have a side to use and I can't tell from the pic that you have it . With these it I also advisable to slightly tighten with a coin to make sure

If a particular string is always moving swap the tuner with a another to see if the issue moves with it.
These tuners although a good design often have slipping issues due to wear or damage to the cam ( sometimes just not built to fine enough tolerances to grip the pain strings well enough ) . I would say they are the most likely culprit of your problem . But you need to polish the nut slots raise the stop tail and snug the tuners with a coin to see if that improves anything.
Finally check the truss rod is not sat at the neutral point. Two way rods have a least a half turn of loose in the middle of the travel it should not be set here. If it is tighten or loosen until it starts to bite and then stop.
See how that goes.

 

[mbenigni]

Ok several things;
The stop tail is too low for the tunamatic.
The nut is just black plastic and can cause issues.
The Tuners have a side to use and I can't tell from the pic that you have it . With these it I also advisable to slightly tighten with a coin to make sure
View attachment 3568
If a particular string is always moving swap the tuner with a another to see if the issue moves with it.
These tuners although a good design often have slipping issues due to wear or damage to the cam ( sometimes just not built to fine enough tolerances to grip the pain strings well enough ) . I would say they are the most likely culprit of your problem . But you need to polish the nut slots raise the stop tail and snug the tuners with a coin to see if that improves anything.
Finally check the truss rod is not sat at the neutral point. Two way rods have a least a half turn of loose in the middle of the travel it should not be set here. If it is tighten or loosen until it starts to bite and then stop.
See how that goes.

Thanks, Eagle - I didn't see you'd replied until just now.

I've experimented with the truss rod quite a bit. I only half know what I'm doing there, but I think I've worked with it at enough different settings now to rule that out as a likely culprit.

Definitely using the correct side of the tuners. They're brand new, and the strings are relatively heavy, so I'd be very disappointed if they were failing to lock properly. I'm not quite clear as to what you mean by "snug the tuners with a coin". I use pliers (and just a bit of torque) to get the nuts locked over the shafts and onto the face of the headstock. Are you referring to the flathead screws on the tuner keys? The tuners are really smooth as I noted before, so yeah, maybe these should be tightened.

I will try raising the stop tail. That wouldn't have even occurred to me but now that you mention it, it makes sense. That string butler is also arriving today, so I may as well try it. From there it's off to a pro to have the nut addressed.

 

[mbenigni]

Tightened the screws on the tuning keys. No improvement.

Raised the tailpiece. No improvement.

Installed the String Butler as an act of final desperation. Night and day difference. Guitar was immediately easier to tune, and now stays in tune... within reason - a really wide bend on the 2nd string will still stretch/pull it flat. As with most guitars, I guess. But we're definitely back in "normal" territory. I'm as surprised as anyone. I really didn't expect this little gimmick to help much, especially after noting the reduced string angles on the larger Epi headstock. Now, is the String Butler arguably a "band aid" for a sticky nut? Yeah, almost certainly - as evidenced by the fact that not every Gibson/Epi is as ornery as this one was in the first place. And yes, the String Butler is a bit of an eyesore - especially since Amazon can't tell the difference between "All Black" and "Black with Chrome(ish) Hardware". Regardless, this is a massive improvement; well worth the $50

Guitar still needs a little unrelated work. The neck is still "bendier" than I would prefer, which may require a truss rod tweak as @Eagle suggested. (And the String Butler has to come off to access the truss rod, which is a PITA.) With the action where I want it, the 5th and 6th strings totally flub out at the first fret, and I think the only solution there is to fill the nut slots and re-cut them. Here we go round again LOL. I feel like the guitar sounds slightly different than before I messed with the tailpiece last night, though I could be imagining things. Might try lowering it again. Will have to recheck intonation, etc...

Getting there, finally. :)

 

[Eagle]

By snug the tuners tighter I mean with a coin slightly tighten the locks so there is no slipping. Do that and fix the nut and you can stay in tune without the horrible thing on the head. The stop tail issue is only a thing if you have it way too low.
Either way eliminating things and getting there.

 

[mbenigni]

By snug the tuners tighter I mean with a coin slightly tighten the locks so there is no slipping. Do that and fix the nut and you can stay in tune without the horrible thing on the head. The stop tail issue is only a thing if you have it way too low.
Either way eliminating things and getting there.

Huh. I hadn't even noticed that the locks were adjustable. (Though now it's obvious just by looking at my own photo above.) Thanks for the heads-up.

I raised the stop tail because I thought you'd seen something specifically wrong in my previous pictures. Will probably drop that back to where it was because... well, why not.

As for taking the String Butler off again... feels a little too much like opening Pandora's Box at this point. The guitar works, so I'll probably leave it be for a bit.

 

[Eagle]

Increasing the friction on the bridge saddles won’t help anything.