Excel Superb circa 2020 - how do the tuning nuts attach to the pull rods?

[fraser]

Hi,

Many thanks in advance!

I have a nylon tuning nut that is just spinning and doesn't affect the tuning rod in any way. It's stripped or loose and I need to put a new one on or reattach the current one. There is no threading on these tuning nuts. Are they glued on or are they somehow jammed (?) on? Please advise.

Fraser

[Marshall Woodall]

My bet is that the problem lies at the bell crank. I don't know when they changed over to all metal barrel nuts but if yours are plastic there is a good chance that your problem is there. You need to check it out underneath. I believe there are replacements available at Mcmaster Carr here in the US (?).

[Marshall Woodall]

and yes, there are some tuning rods that are physically attached/glued to their tuning nuts

[Oliver Samland]

Hi Fraser,
on older Excels the tuning nuts are permanently fixed on the pull rods. By turning the nut, you basically spin the whole rod into a nylon cylinder sitting in the bell crank (so the pull rod has it's threads at the bell crank side, not at the changer).
You say your tuning nut that came off has no threads. Does the associated rod has threads on the changer end?
(I'm not exactly sure about ~2020 Excels, though. I thought Mitsuo had adopted the common design with rods fixed on bell cranks long before 2020.).
I'll follow this topic as I'm curious about the answer to your question, too. On my like 40 year old Excel, all tuning nuts still sit firm on the rods, I wonder how they hold so well.
Good luck!

[Ian Worley]

Do your bell cranks look like this? If so it's likely just a loose set screw on the little barrel connector that holds the pull rod at the bell crank

20251014_165153.jpg

[Toshiyuki Shoji]

I was definitely involved in the build of the 2020 Excel.

Excel and SHOJI use the same design for the bell cranks and tuning nuts.
In the current Excel models, both metal and nylon barrels are used.
Generally, the metal barrels are the standard choice, but in some cases — such as for the bidirectional knee levers (LKR and RKR) — nylon barrels may be used instead.

If the nylon nut that’s slipping is connected to a pull rod with a **metal barrel**, then as you mentioned, Ian, it’s quite possible that the **set screw on the barrel has come loose**.

[Dan Beller-McKenna]

Thanks for that clarification, Toshiyuki. Can you explain why the threaded nylon barrels at the bellcrank are considered advantageous to right moving knee levers?
Thanks.

[fraser]

Hi,
Thanks everyone!

I do believe you are correct about the loose set screw. I thought I put my fingers on the tuning rod while adjusting the tuning nut and it wasn't moving, leading me to believe the nut was stripped. I looked at it more carefully today and the rod is turning when you adjust the tuning nut and is loose at the bell crank end.

What tool do you use to adjust the set screw? The opening looks round and my hex wrench doesn't fit very well. I can't get into this one so far, to tighten it.

Hi Toshiyuki, you may have been involved. It was in progress and then Mitsuo told me due to Covid, he shut down his factory, sent his workers home and finished it himself, either at home or at the factory.

I have some extra tuning nuts and they are not threaded. I can''t tell about the rod since the nut is spinning - it didn't fall off. How do the tuning nuts get put on, anyway?

Fraser

[Larry Allen]

These are the smallest Allen wrenches that came with all 5 of my Excels for the metal barrels

[fraser]

Thanks! I think I have those same ones.

You have 5 Excels?


Fraser

[Larry Allen]

Started out in the 60s with Sho_Buds, then a Carter, got an Excel next, great guitars, had one for the road, 2 in 2 studios , 2 at home.. passed them on to forum members kept one, retired 81 YO.. home band room..easiest guitars to work on, last one here

[Toshiyuki Shoji]

Thanks for that clarification, Toshiyuki. Can you explain why the threaded nylon barrels at the bellcrank are considered advantageous to right moving knee levers?
Thanks.

Let me explain the reason why nylon barrels are used for the LKR and RKR.
This photo shows an S-12. On both the SHOJI and the Excel Superb(Exstar) models, when a simple setup is used without the reversing mechanism, the bell cranks for the LKR and RKR are mounted in the opposite position from the usual — between the bottom of the cabinet and the cross shaft.

Because of this limited space, there isn’t enough room to insert and turn a hex wrench, so it’s not possible to secure the pull rod with a set screw as with the metal barrels.

Please tighten the set screw on the metal barrel using a 1.5 mm hex wrench.