If I get this right the existing plate screw holes get plugged and re-drilled for the 4" socket set screws. The new board at the screw locations is counter sunk to accept the serrated flange nuts (are these the lock variety) that are set deep enough to not interfere with plate height. Are the shoulders oriented up to support the plate? Lock tite applied? I suppose that nut and set screw need to turn together to make adjustment? The socket screws are adjusted from above with Allen wrench and set high enough above plate to accept acorn nuts. thanks Gene Sent from my iPhone On May 29, 2012, at 10:21 AM, Ron Nossaman <rnossaman at cox.net> wrote: > On 5/29/2012 12:05 PM, Encore Pianos wrote: >> This is what you need, all from Fastenal: Idea from Ron Nossaman >> originally I believe. >> >> 3/8"-16 x 4" Black Oxide Alloy Steel Cup Point Socket Set Screw >> >> 3/8-16 Nickel Plated Acorn Nut >> >> 3/8"-16 Zinc Finish Case Hardened Serrated Flange Nut >> >> The Flange nut is inverted and epoxied in place along the length of >> the Allen set screw so that the shank will protrude far enough above >> the plate so that you can turn down the acorn nut without bottoming >> out before touching the top of the plate. > > Almost. It's a lock nut, and epoxy isn't needed, though I use a drop of thread locker for insurance when I assemble them. Hint: use a relatively small diameter lock nut and counter bore the soundboard so it will screw down flush before installing. It's no fun having the plate still 1/2 a lock nut's thickness too high while you're setting bearing with a laminated cap pinned bridge installed. > > Ron N
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