Action flange crushing

[Ron Nossaman]

>inthe early days i remember ptg convention classes and instructor told
>about 18 lbs torque for hammer and whippen screw.. i got a torque wrench
>and practiced a little and anybody can get that feell.. it works.. a few my
>collegues came to my shop and practiced with torque wrench to get that
>feel.. try it!!
>
> > [Original Message]
> > From: Phillip Ford <fordpiano@earthlink.net>
> > To: <pianotech@ptg.org>
> > Date: 11/16/04 2:20:33 PM
> > Subject: Action flange crushing
> >
> > I am continuing to investigate action screw torque.  One thing that
> > has turned up on some correspondence is the admonition not to crush
> > the flange.  Any thoughts on why this is a bad idea, other than
> > aesthetics?  Would the flange have a tendency to get loose sooner as
> > a result of some crushing?  Is the magic circle of sound
> > detrimentally affected by flange crushing?
> >
> > Phil Ford


Hi guys,
I've seen a number of crushed and split flanges through the years. Does it 
hurt anything? Only when it hurts something. Like anything else we do, it's 
a matter of degree. It seems to me that most badly crushed flanges weren't 
crushed by ham-handed tightening of screws, but by insisting on tightening 
the screws every dry season, so the expansion of the flanges during the 
damp season would crush it a little more every year. I used to see this 
mostly on Kimballs and Baldwins around here, where you had to space hammers 
with every single tuning, and tighten the flange screws enough to get them 
to stay there at least temporarily.

Ron N