threaded rod for balance wheel is spinning

[KenanJ]

Apologies for the delay - I was searching for my spare cylinder with the scratched threads, @KenanJ, then decided it wasn't worth the extra wait.

If you remove the cylinder and wheel from the guitar, you can test the wheel threads using the two cylinders you have (the one you replaced because you suspected the threads were damaged, and the NOS one you purchased):


wheel and threaded cylinder.JPG


In my case, the cylinder I know to be working threads all the way through one side of the wheel and out the other. Though sections along the middle required more effort, it never became "stuck", or forced me to thread in the opposite direction to loosen it. After applying some tri-flow lubricant (for no reason other than I happened to have the bottle sitting out where I could easily retrieve it) to the wheel and cylinder threads, running the cylinder through the wheel in each direction a few times did make it progressively easier.

So, in your case: Have both parts out of the guitar, use a permanent marker or something to distinguish the cylinders, lubricate the threads of both cylinders and the wheel, and then use both hands to attempt to thread the cylinder you suspect of having damaged threads through the wheel. If this proves difficult or impossible, back it out and try the "new" cylinder: If the results are the same, then you've diagnosed the wheel threads as being the problem. Whether it's due to accumulation of debris, corrosion, or scratches, I can't say without seeing it.

Thank you for your answer @mmmguitar,

I lubed the thread of both rod (old and new) with some bycicle vaseline and I also tried white lithium grease, althought I saw a change in the smoothness I seemed the new rod was harder than the old one that's why I suspect a use in the threaded hole of the wheel. However I will buy a ptfe lube (like the tri-flow you're advising since it's note available in France but I saw that it's PTFE based to it should do the trick) and try it again.

I also bought a file (see attached picture) to "repair" the threaded hole which appear to be 20 threads per inch. I guessed that using @vjmanzo topic on the rod replacement part https://www.mcmaster.com/94435A533/.
By searching on the internet people say it can repair lightly damaged threads so I will try this as well.

In case of any ot the above don't work I saw a replacement wheel on eBay but it's in the UK and I will get murdered with custom fees so if anyone here can mail me a spare one it could be nice !

The other concern I have is that after lubricating the old rod (I didn't try this step with the new rod since it's was harder) I tried to setup the guitar but when going to home position and try (under spring tension) to show 10 threads it's nearly impossible like the wheel don't spin anymore and the rod spin with the wheel. So after that I was able so show like 6/7 threads but the the three ridge bumper was already touching the step stop so I'm like okay I'm fine then I retract the spring so it's barely toucing then I tune up and I try the floating mode but when doing this it only show 3 threads or less so went I pull up the spring fall, that's why I'm also confused about the 9 spring I have and will try your process with the other 10 spring I have when I receive my set a XL 10s.

I will try to post some shots when I rework on the 97 supreme but it's hard since I'm working with 2 hands ^^

[KenanJ]

Hey guys,

After digging in a little more, I tried both rods, I even tried to smoothen some damaged thread with the tool I got but nothing changed, I took some video that I share with you below to have tour thoughts on that, my conclusion is that the wheel is the problem, It's a bit sad because I think the wheel also damaged a little bit the new rod I bought (see atached pic).

For the videos

New rod with thension:
New rod new spring:
Old rod with tension:
Old rod no tension:

I hope the links work fine

[vjmanzo]

Hi @KenanJ—are you certain the insert inside the threaded rod cavity is not spinning?

It’s difficult to see, but inside the cavity where the threaded rod goes, there’s an insert that lines the walls and there’s a protruding notch in that insert that mates with the notch in the threaded rod. It’s glued in place and it’s possible that it has come loose in which case it would begin spinning once you get far enough with the threaded rod.

If you take the threaded rod and wheel out, you should be able to feel the insert in the cavity—maybe check to see that it can’t simply be pulled out?

[mmmguitar]

In addition to VJ's question: Am I correct to infer that, even with the wheel and cylinder taken out of the guitar, neither cylinder can be threaded all the way through the wheel?

[KenanJ]

In addition to VJ's question: Am I correct to infer that, even with the wheel and cylinder taken out of the guitar, neither cylinder can be threaded all the way through the wheel?

When I take out the easiest I the old rod it spins easily (I added lube before) and the new rod is okay but at the end it hard to spin it out.

[KenanJ]

Hi @KenanJ—are you certain the insert inside the threaded rod cavity is not spinning?

It’s difficult to see, but inside the cavity where the threaded rod goes, there’s an insert that lines the walls and there’s a protruding notch in that insert that mates with the notch in the threaded rod. It’s glued in place and it’s possible that it has come loose in which case it would begin spinning once you get far enough with the threaded rod.

If you take the threaded rod and wheel out, you should be able to feel the insert in the cavity—maybe check to see that it can’t simply be pulled out?

I will check that tomorrow morning and try to get quality shots in the morning light

[KenanJ]

Hi @KenanJ—are you certain the insert inside the threaded rod cavity is not spinning?

It’s difficult to see, but inside the cavity where the threaded rod goes, there’s an insert that lines the walls and there’s a protruding notch in that insert that mates with the notch in the threaded rod. It’s glued in place and it’s possible that it has come loose in which case it would begin spinning once you get far enough with the threaded rod.

If you take the threaded rod and wheel out, you should be able to feel the insert in the cavity—maybe check to see that it can’t simply be pulled out?

But from what I saw I didn’t seem loose. Besides that when I hold the rod and spin the wheel it sides r spin inside the wheel hole that’s why I suspect to wheel to be off …

[KenanJ]

Hey @vjmanzo !

I think you were right, I will show a video of the metal piece inside the cavit spinning inside, as well at the small metal sheet piece being unglued, what product should I use to reglue the metal piece inside and the metal sheet above?

Here is a video of the metal piece inside spinning:

and this is another video to show how to old rod spin inside the wheel:

Cheers

[vjmanzo]

Okay!!!! Now we’re getting there!

I recall doing this to a Fly once before and using Zap (CA Glue); there might be other glues that are better, but that’s what I had and it’s held. Just make sure that the little ridge on that insert is lined up with where the ridge on the threaded will be.

[KenanJ]

Okay!!!! Now we’re getting there!

I recall doing this to a Fly once before and using Zap (CA Glue); there might be other glues that are better, but that’s what I had and it’s held. Just make sure that the little ridge on that insert is lined up with where the ridge on the threaded will be.

So I can use ca glue on both the mettalic circle sheet and on the metal piece inside ? I will try and see how it goes but there is a lot of grease since I lubricate there is there any product to remove some grease ?

[billy]

Not sure if you checked this but there is a slot on the rod. This slot slips into a notched bushing at the bottom of the spring cavity.

It’s possible that bushing notch is missing or damaged as a result of a rod that needed lube. If so, the rod will spin with the knob.

There may be a way to add a new “notch” with a screw or something but not sure off the top of my head.

[billy]

Just saw your latest set of videos, so the bushing is spinning when it shouldn’t.

I think you can carefully epoxy the bushing and pad. Let it cure for a day or so and if should be good.

Also you can try cleaning up (chasing) the knob threads with a tap, maybe a local machine shop can help you out.

[KenanJ]

Just saw your latest set of videos, so the bushing is spinning when it shouldn’t.

I think you can carefully epoxy the bushing and pad. Let it cure for a day or so and if should be good.

Also you can try cleaning up (chasing) the knob threads with a tap, maybe a local machine shop can help you out.

thanks Billy!

I just bought epoxy yesterday I will try to do it today when I have time, I don't know if you saw but in my post I mentionned I tried to clean the threads with a special tool but it didn't help much, are you referring to this type of tool?

[KenanJ]

Hi all,

So today I finally put some epoxy back to fix the spinning issue.

I sanded with 400 grit both the inside cavity and the plastic piece.

I was surprised that the piece is in plastic. I used very gently a pliers to get the plastic part out of the slot.

I also glued back with ca glue the top protection sheet. I was a bit hard since it had small imperfections. The job was not perfectly centered but I removed the tiny excess with a cutter and I think the result is fine.

I wanted to align better the Ridge but I think it’s not too bad.

A thing to know is that using the epoxy made a really really tight fit so I had to rush to center the piece and then clean the excess.

I attach you the product I used and some pictures.

Cheers