[CAUT] S&S hammer flange rail material

[Alan McCoy]

This problem of screw angle driving the flanges to an uneven resting place
is well documented in Ed McMorrow's book. He does a good job of illustrating
it and discussing the solution.

Alan


> From: Fred Sturm <fssturm at unm.edu>
> Reply-To: "College and University Technicians <caut at ptg.org>" <caut at ptg.org>
> Date: Wed, 20 Aug 2008 12:56:18 -0600
> To: "College and University Technicians <caut at ptg.org>" <caut at ptg.org>
> Subject: Re: [CAUT] S&S hammer flange rail material
> 
> On Aug 20, 2008, at 6:51 AM, Chris Solliday wrote:
> 
>> The one deviation from factory that I do now is add a washer on the
>> top of
>> the flange. It helps keep the flange level and particularly keeps
>> the front
>> from moving up or down which can alter the centerpin height. I think
>> that it
>> is important to maintain that measurement for many obvious reasons.
> 
> Talking about the front of the flange moving up and down, I had an
> early 1980's B I put new parts on last year, and when I had installed
> the shanks and flanges, the fronts were all over the place. Put a
> straight edge on, and there were gaps up to maybe 1.5 mm between the
> highest and lowest. I traced this to bad drilling: the screws were
> angled coming out of the rail, and they carried the flange with them.
> (Put a straight edge next to the screws, and the drilling line had
> about as much variance as the flange level).
> My solution was to enlarge the screw hole a bit fore or aft (angle
> matching the screw's, done with a round file), shim front or back of
> the flange (all the way across, on the curved part), and then I found
> I needed to chisel the top of the flange where the screw bears on it
> at an angle to account for the angle of the screw. Otherwise, the
> screw top would overcome the action of the shim. Not all that much
> work, once I figured it out, but it sure was disconcerting to find. (I
> didn't get it perfect, just addressed the worst culprits and figured a
> wee bit of variation - 0.5 mm or so - wouldn't hurt that much).
> Having those flanges uneven like that makes regulation a little
> strange, especially the drop screws. I had had problems with that
> action all along (original parts), but the most obvious part of it was
> the too short tails (closest possible checking at 7/8" or more), and
> so I never really looked into it, figuring I'd replace parts pretty
> soon.
> Anyhow, it's something to watch for. I've seen it on other Steinways
> to lesser degrees, but this one was amazingly bad.
> I think the new pan head, low profile screws have enough surface area
> to make a washer unnecessary, but some of the old screws have pretty
> narrow heads, so adding a washer isn't a bad idea.
> Regards,
> Fred Sturm
> University of New Mexico
> fssturm at unm.edu
> 
>