Spacing of 12 strings

[Ian Rae]

This is a bit of an odd question from someone who's just finished building a 12-stringer, but what should be the distance between the top and bottom strings (at the bridge)? My first effort has definitely come out too wide at 4.2", and the 1st & 12th strings are not quite as loud as the others. (This is to do with the metric/imperial twilight zone we Brits are forced to live in.) My next effort will measure 3.9" - is this within what a typical pickup manufacturer expects?

[Lane Gray]

I'm not near mine, but I recall them as being 3/8“ apart, so they'll be 4.125 (11 gaps)

[richard burton]

Aim for 3.77" from centre of 1st string to centre of 12th string, this will give you the 'standard' string spacing of 11/32".
I'm sure that I've played a 12 string sometime, possibly a Zum, which had a narrower than standard string spacing (5/16"), and was very difficult to play with such a narrow string spacing.

[Jim Smith]

Aim for 3.77" from centre of 1st string to centre of 12th string, this will give you the 'standard' string spacing of 11/32".
I'm sure that I've played a 12 string sometime, possibly a Zum, which had a narrower than standard string spacing (5/16"), and was very difficult to play with such a narrow string spacing.

Richard is correct, the accepted string spacing for 10 and 12 string pedal steels is 11/32".

11/32" = 0.34375" x 11 = 3.78125

[Ian Rae]

This is promising. Steel is sold in metric sizes here, so if I use 6mm fingers with 3mm spacers, it'll come out at 99mm = 3.90" which is only 0.12" over Jim's 3.78" Now there are 44 surfaces between the 23 components and 0.12/44 = 0.0027" - I should be able to lose that when I shine the parts up on the sander. Thanks, everyone!

[Glenn Uhler]

Instead of buffing down the 6mm stock, I would just use slightly thinner spacers. Unless the 6mm bar stock has a ground finish, I would sand it very lightly with 400 grit paper to make sure it is perfectly flat and there are no burrs on it.

[Ian Rae]

For this first changer I used black steel for the fingers and the spacers (which are also the axle braces) as it was pretty much experimental - I had no idea it would turn out as well as it did. For the next one it makes sense to do what Glenn suggests and use cold finished bar (unground) which will be flatter and need only minimal sanding, and then thin the spacers as required.

[Glenn Uhler]

Ian,
I don't imagine ground stock 6mm x 20mm would be that much more expensive than cold-finished (or cold-rolled, as we say here in the States). You want as smooth a finish as possible where the fingers touch the spacers. (No binding.)

[Ian Rae]

If I can get it I'll try it - anything to save buffing!