Import Bigsby and the Chet arm. A cautionary tale.

TConnelly

Electromatic
Jun 5, 2022
6
Sandy Or.
Greetings all.
I recently posted this on the Strat Talk forum in the "Other Guitar" section because I didn't belong to any hollow body forums. I don't own a Gretsch.....yet. Someone there suggested I post it here, so I decided to go ahead and join.

I have a Cort Yorktown BV that I recently installed a Chet Atkins Bigsby arm on. I thought I would post this because I ran into an issue that I didn't foresee and I hope I can help someone else to not make the same mistake I made.
20220604_165131_resized.jpg
As everyone here knows, when you install a Chet arm on an import Bigsby you have to ream out the hole in the arm mounting bracket to 10mm to make the 3/8" US bracket fit on the 10mm import shaft.
20220604_170148_resized.jpg
I got an inexpensive reamer on Amazon. If you decide to do it by hand like I did, it's very easy to get it off kilter. If I had it to do over again, I would probably still do it by hand but I'd go a little bit from one side then the other and alternate until I'm through instead of just going all the way through from one side. I assumed that since I was taking off so little that it would self align and stay straight. Not so much! Or you can use an adjustable reamer as some threads on here have shown.
You can see here how I messed up. The bracket is angled slightly out to the treble side and it makes the spring crooked.
20220604_162322_resized.jpg 20220604_162336_resized.jpg
It works fine the way it is but it's gonna bug the crap out of me until I can figure out how to fix it.

I also needed to use the 1 1/8" Bigsby spring plus a washer under the spring with the Chet arm. Because it ends up so much lower than the stock arm.

Another tip is, I've never been real happy with the way the stock arm pivot spring feels. I like to be able to flick the arm out of the way with my pinky. But with the stock spring, If it was loose enough to flick out of the way then it would flex on the bracket. And if it was tight enough not to flex, then I'd have to shove it out of the way. So I found some Belleville spring washers
index.jpg
at McMaster Carr. 12mm x 6.2mm x .5mm
20220604_171214_resized.jpg
The cool thing about them is that they can be "stacked", like the bottom half. Or "nested" like the top half to give just the spring rate you need. They work awesome! Here they are on the stock arm.
20220604_173522_resized.jpg
It's super easy to dial in just the right feel with these.
Cheers..............................Todd
 
Last edited by a moderator:

WillyW

Electromatic
May 3, 2022
52
ABQ
Whomever recommended a reamer for that job deserves a kick in both nuts, you deserve a single tap for listening to them.

quite a few geetarists should not own tools, unfortunately they don’t know who they are..
 

fasteddie455

Electromatic
Jan 27, 2010
9
Arlington, Texas
I originally had every intention of doing mine on the drill press. I got concerned that the drill press may be a little fast and aggressive for the reamer. Plus I just got impatient. Good luck with your project!
Cheers................Todd
You can always chuck it up in the press but just turn it by hand, that way it is still controllable while maintaining 90 degrees…
 

fasteddie455

Electromatic
Jan 27, 2010
9
Arlington, Texas
Greetings all.
I recently posted this on the Strat Talk forum in the "Other Guitar" section because I didn't belong to any hollow body forums. I don't own a Gretsch.....yet. Someone there suggested I post it here, so I decided to go ahead and join.

I have a Cort Yorktown BV that I recently installed a Chet Atkins Bigsby arm on. I thought I would post this because I ran into an issue that I didn't foresee and I hope I can help someone else to not make the same mistake I made.
20220604_165131_resized.jpg
As everyone here knows, when you install a Chet arm on an import Bigsby you have to ream out the hole in the arm mounting bracket to 10mm to make the 3/8" US bracket fit on the 10mm import shaft.
20220604_170148_resized.jpg
I got an inexpensive reamer on Amazon. If you decide to do it by hand like I did, it's very easy to get it off kilter. If I had it to do over again, I would probably still do it by hand but I'd go a little bit from one side then the other and alternate until I'm through instead of just going all the way through from one side. I assumed that since I was taking off so little that it would self align and stay straight. Not so much! Or you can use an adjustable reamer as some threads on here have shown.
You can see here how I f'd up. The bracket is angled slightly out to the treble side and it makes the spring crooked.
20220604_162322_resized.jpg 20220604_162336_resized.jpg
It works fine the way it is but it's gonna bug the crap out of me until I can figure out how to fix it.

I also needed to use the 1 1/8" Bigsby spring plus a washer under the spring with the Chet arm. Because it ends up so much lower than the stock arm.

Another tip is, I've never been real happy with the way the stock arm pivot spring feels. I like to be able to flick the arm out of the way with my pinky. But with the stock spring, If it was loose enough to flick out of the way then it would flex on the bracket. And if it was tight enough not to flex, then I'd have to shove it out of the way. So I found some Belleville spring washers
View attachment 182540
at McMaster Carr. 12mm x 6.2mm x .5mm
20220604_171214_resized.jpg
The cool thing about them is that they can be "stacked", like the bottom half. Or "nested" like the top half to give just the spring rate you need. They work awesome! Here they are on the stock arm.
20220604_173522_resized.jpg
It's super easy to dial in just the right feel with these.
Cheers..............................Todd
I am wanting to try the Belleville washers but cannot find the ones with the dimensions that you provided.. can you further explain which ones you used or provide a link? I would be greatly appreciative!
 
Last edited:

TConnelly

Electromatic
Jun 5, 2022
6
Sandy Or.
Here they are. Belleville spring washers. I got two 12 packs of both the .5mm thickness and the .6mm. I haven't tried the .6mm size because the thinner one worked just fine. If you try it, let me know how it works out.
Cheers........................Todd
 


Top