Ebondy tuner knobs

[markishandsome]

On my last build I switched out the plastic tuner knobs that come on the Schallers with the stew-mac Waverly-style ebony knobs. The knob-holes had to be filed out a bit from rectangular to round, but it's a pretty good fit on the shaft. I've tried both superglue and gorilla glue but the knobs keep coming loose when tuning up. Should I be using some sort of epoxy? Thanks!

[Dave Cohen]

Mark, I drill out the Waverly ebony buttons with an 11/64" bit. You have to be careful not to drill deeper than necessary for the Schaller shafts. I support the buttons in a drill press vise with some inner tube material for cushioning, and take some care to make sure that (a) the hole is vertical, and (b) I don't chip any material from around the edge of the hole. The 11/64" hole is almost a press fit to the knurled Schaller shaft, and will hold without any glue, though I use a drop of ca through the residual screw hole. Once you are done, you can fill each screw hole with an ebony scrap sharpened in a pencil sharpener, or glue the screw in for the Waverly look (might have to shorten the screw a bit).

http://www.Cohenmando.com

[labraid]

Schallers are built to millimeter specs, and the actual is 4.2mm (11/64" = 4.37mm); buttons should be heat pressed on: heat shaft with 1/4" flame 12 seconds, and press in with vise. no glue; hydraulic pressure can split the button. (well, unless they're the StewMac ones I guess, but if you make yer own minus top screw hole...)
Hole is 11mm deep. You can get the 4.2mm bit from McMaster-Carr.

[Dave Cohen]

The difference between 4.2 mm and 11/64" is 0.0065". When I drill the buttons with an 11/64" bit, they press on snugly, do not split, but also do not twist or slip on the shaft. I press 'em on dry, then put a drop of ca through the screw hole. Or, if I am going to fill the hole with an ebony plug, I prepare the plug first (pencil sharpener), put in the drop of ca and immediately press the plug in place. The plug can be trimmed and buffed after the ca dries. Works fine.

http://www.Cohenmando.com

[markishandsome]

I put these buttons on a few months ago, I'd rather fix em up than buy a new set from s-m plus shipping plus a drill bit etc... Is there any way to save these buttons?

By the by, I stuck some short 4-40 machine screws into the screw holes, they threaded right in with no glue. They look great.