Very pretty tuners had to be put on upside down 😭 (Gibson A)

[pops1]

Basically I can turn the pegs on either of the A's and nothing happens. I keep turning and suddenly it's too sharp so I have to turn it back the other way. I think this is most likely a nut issue.

Yup

[rcc56]

I would expect a mandolin with a serial number in the 87000's to have the peg holes drilled for the modern post spacing [29/32"].
It's not impossible that it could have been drilled for the older 15/16" spacing, but if so, it would be an anomaly.

Cease and desist until you measure your tuners, both old and new. Don't start filing the nut until the tuners have been measured.

If the post spacing on your replacement tuners is different than the spacing on your original tuners, it can cause the posts on your new tuners to bind and cause tuning problems. No amount of adjustment elsewhere will keep the posts from binding.

If the post spacing is the same on both the original and replacement tuners, then the cause of your problems indeed lies elsewhere, such as binding at the nut, slipping string loops, poor string installation [I like 5 wraps around the tuner post in a nice coil for the plain strings], tailpiece problems, etc. In that case, I would change the strings and check the nut first.

Unless your eyes are much sharper than mine, and your hands are very steady, it can be difficult to get an accurate my measuring from one post to its closest neighbor. Instead, measure from the first post on the plate to the last post on the plate. Your measurements should be "center to center."

Do not take your measurement at the top of the tuner posts-- it may yield inaccurate results. Instead, take your measurement either where the posts contact the plate, or take a center to center measurement of the circular gears.

If your original tuners measure slightly greater than 2 3/4", the tuners have the earlier 15/16" post spacing, and you will need to use either the "restoration" tuners that I see in your pictures, or have Rubner make you up a set of worm over tuners with the 15/16" spacing.

If your original tuners measure slightly less than 2 3/4", they have the modern 29/32" post spacing, and any standard modern worm over tuners should work.

A measurement of the actual post holes in the peghead would also be a good idea. Take that measurement from the back of the peghead.

[HoGo]

Unless your eyes are much sharper than mine, and your hands are very steady, it can be difficult to get an accurate my measuring from one post to its closest neighbor. Instead, measure from the first post on the plate to the last post on the plate. Your measurements should be "center to center."

Do not take your measurement at the top of the tuner posts-- it may yield inaccurate results. Instead, take your measurement either where the posts contact the plate, or take a center to center measurement of the circular gears.

Agree with all rcc56 wrote. When I measure tuners I measure with calipers across all four posts at the base and subtract thickness of one post. That gives you center to center distance. If you want to measure distance of holes in headstock the bottommay be chipped or worn and on these old mandolinsmay be oversized so thay wouldn't cause binding but the bearing surfaces at the bushing edges would. If the bushings are firm fit I would measure the largest distance of holes in bushings with the upper jaws of the caliper and subtracct one inside diameter (again measured with the caliper).
Simple check of fit for given set of tuners is inserting them through bushings from top. If the fit is correct then they will freely go all the way to the tuner base touching the tops of bushings (you may notice some tuners bases are slightly bent due to peening/riveting of the worm holding tabs so straighten them first a bit). Ideally there would be no binding of posts against the bushings when inserted.

[MikeEdgerton]

Going back to the intonation problems, Gibson fretboards from early on have been the victims of frets that weren't slotted right in the first place. In the past folks like the late Paul Hostetter spoke of a gangsaw that was in use at Gibson and not set correctly. Others have spoken over the years of compensating for some of this at the saddle or nut and many fretboards have been replaced. In other words don't assume the fretboard isn't the cause of the intonation issue.

[GTison]

Interesting. Multiple issues here. 1. Upside down tuners that turn backward to the norm. I've seen plenty of old Gibsons with the corners ground off the tuners to match the headstock. Just look through the mandolin archive. As long as they work, which is also questionable on golden age tuners.
2. Nut issues. It seems hard to find a person to fix mandolin nuts properly. Going sharp after tuning seems like a nut problem.
3. Tailpiece. Not sure that using those secondary hooks makes any difference.I used to do that.The inside E string looks like it could break going around that primary hook.
4. Intonation. Setting the bridge/saddle is important to get the best intonation. This is OFTEN poorly done esp on an old one. Set the bridge then you can complain about the frets being wrong.
5. Oh yes and make sure you string lock around the post using some method. That will insure that that their is no slippage.

I wish you A model success. I like my old knockabout Gibson A.

[devlord]

Follow-up:

I had the luthier file the nut down a little for the bass-side A string and he used a mechanical pencil to put graphite on it. Then I had him re-install the original tuners and all is good now. Thanks everyone for helping me figure out the problematic tuner issue.

[liestman]

see next post.

[liestman]

It would appear that by that point in time Gibson was using a totally different tuner style than the two types that are available. If the post spacing is an issue I'd be more inclined to grind of a wiggle end piece. Those tuners have the old spacing. If the spacing is actually the modern spacing I'd probably put a set of Rubners on it. Have you still got the original tuners?

https://www.rubnertuners.com/mandolin-machines

Mike, where did that middle picture come from and do you have any info on those tuners? I have a 1932 mandolin made by Paramount with those exact tuners on it and they are indeed midway between the teens spacing and modern spacing, at around.922", they have .220" shafts with no indent where the string wraps, no bushings, the same outside engraving as in that picture, and the usual Waverly Musical Products on the underside.

[MikeEdgerton]

Mike, where did that middle picture come from and do you have any info on those tuners? I have a 1932 mandolin made by Paramount with those exact tuners on it and they are indeed midway between the teens spacing and modern spacing, at around.922", they have .220" shafts with no indent where the string wraps, no bushings, the same outside engraving as in that picture, and the usual Waverly Musical Products on the underside.

I got the pictures out of Dan Beinborn's Mandolin Archive. I was just searching through the A style mandolins in the late 20's with images. Those tuners were common on Gibson's up through the 30's as well. They also had F style tuners. Somebody should know who made them.

I do see the OP had different tuners than we had expected.

[devlord]

I got the pictures out of Dan Beinborn's Mandolin Archive. I was just searching through the A style mandolins in the late 20's with images.

Mine match the one on the right, which is the same model, off by 5 serial numbers from mine. I'm glad to have the originals back on but there are marks from where the temporary ones were.

[liestman]

I got the pictures out of Dan Beinborn's Mandolin Archive. I was just searching through the A style mandolins in the late 20's with images. Those tuners were common on Gibson's up through the 30's as well. They also had F style tuners. Somebody should know who made them.

I do see the OP had different tuners than we had expected.

On the underside of the plate, they have the typical Waverly Musical Products New York engraving. Thanks for the info! Is there a name for that spacing? I guess no modern replacement tuners are available.

[MikeEdgerton]

On the underside of the plate, they have the typical Waverly Musical Products New York engraving. Thanks for the info! Is there a name for that spacing? I guess no modern replacement tuners are available.

No name that I know of. There are some inexpensive odd spaced tuners out there that I have been able to find for folks, mostly imported that for some reason made it into the manufacturing world. Saga used an odd spacing on a few years of modern KM-150's that drove people crazy trying to replace. I don't know if they still use that spacing or not.

[pops1]

There are always replacement tuners if you want them. Before there were replacement tuners for the odd spacing I simply cut the plates at the screw holes and used whatever tuners I wanted. The small difference will still allow the screws to hold the tuners on, event tho you cut the plates at the center of the screw holes. It will also allow the tuners to be the spacing you need without altering your mandolin.

[Richard500]

I’ve mentioned a few times that measurements of old mandolins show a large variety of spacings; certainly there is no particular commercial reason to either have a standard, or to expect that a lot of instruments will ever have anything changed except strings. Even more fun, I was surprised that on some bowl backs, the tuners operated “backwards”. Folks here assured me that at least that the direction of peg turning was, indeed standard, but examination of mounting holes and imprints in finish shows that some tuners were intended to work the other way, at least on my instruments.
Brings back memories of my years at what was the National Bureau of Standards; an oxymoron of a name since the United States actually has very few national standards for the many measures one might think important. Sort of a wild West, which makes engineering things here so complicated, and sometimes makes rockets miss Mars….