Monday's Trigonometry Challenge

[Matt Rayner]

Dear colleagues

I have a Wilkinson-type roller bridge that I wish to fix on my Telecaster guitar which has a Bigsby whammy bar..

The bridge was designed for a guitar with a 12" radius neck. However. my Telecaster has a 7.25" radius neck.

As you can see in the front elevation pic, the string saddles sit on their own steps in order to match the 12" radius. Obviously, the two middle steps are the same height - as are 1 and 6, and 2 and 4. The steps are 10mm wide (10 - 10- 20- 10 -10)

So. I have access to a milling machine. How much higher should the middle steps be than 1 and 6? I guess the height of 2 and 4 is in the middle. See. I ain't so thick. Anyway. You win the internet for a week if you can figure it out.

Many thanks

-M

[Matt Rayner]

Actually, I think I've figured it out. That width of the steps wasn't accurate. Sorry.

I drew a 7.25" arc. I measured across the middle of all the saddles which was 52mm. Yeps. String spacing.
I drew a line 52mm that touched the arc at 0mm and 52mm. I measured how much higher the arc was at 26mm and it was 3mm.

And there's your interesting fact of the day.

[mettelus]

Be sure to match your intended arc to the rollers, then adjust the steps accordingly. The D and G strings are not on the highest point on the arc, they straddle it +/- roughly 5.2mm for that 52mm spread.

[Matt Rayner]

Correct! I realised that last night. Thanks.

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