[pianotech] S&S K(52) Restoration

[Encore Pianos]

I have found it useful to make a pattern of the plate bolt holes and assign
each socket screw its corresponding hole.  The reason for this is that the
plate thickness can vary substantially depending on the piano.  What you
don't want to find out after the plate is in is that either the acorn nut
bottoms out on the screw before it reaches the top of the plate, or there is
too little of the screw thread showing to thread the acorn nut onto it.  You
may be surprised how much variation there is from hole to hole.   It takes
very little time to do it this way and it could save you some grief. 

Will Truitt




-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Gene Nelson
Sent: Tuesday, May 29, 2012 3:47 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] S&S K(52) Restoration

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