flangemangle

[Ron Nossaman]

Hi gang,

About the time I think I've seen all the simple, basic problems there are -
up comes another one.

I spent over three hours today trying to get an old Yamaha studio working
in a student practice room today. The hammer center pins had migrated out
and the hammers were flopping all over the place. I had declined to tune it
the last two years until they had some money for minimal repairs. This year
they found some money (I can only wonder where), and were terrified that
they wouldn't come up with something to spend it on before June. Then they
remembered the old Yamaha.

Apparently, the techs who had preceded me had noticed flopping (technical
term) hammers and had done what one does for such things. They had
tightened the flange screw. When that didn't work, they naturally tried it
again and further tightened the flange screws. Then they quit. No sense
pursuing obviously counterproductive procedures or digging in and figuring
something out when there were tunings to do. 

I loosened the butt plate (butt clamp?) and slid in what pins I could to
center them, pulling the whole butt/flange assembly where necessary to get
them to move. As I was repinning and rebushing damaged flanges, I noted how
hard it was to push some of the flanges onto the butt. Taking a closer look
at the flanges, I noticed something I don't recall seeing before. Where the
flange screw had mashed the flange to about half thickness, it had spread
the flange at the screw hole. This spread had correspondingly narrowed the
flange fork to the point where it gripped the birdseye/2 and produced
enough friction to hold the hammer off of the rail. Swell. So I got to add
another half hour to the total time whittling the forks for clearance as I
went. If this had occurred to me before the fact, I would have just
replaced the flanges and gotten on with it. It would have been much more
cost effective, though more expensive total, and not set the land mines for
a future date. Then again, if the past techs had investigated and
discovered how this particular pinning system worked, the flanges wouldn't
have been trashed in the first place. 

Curse you Murphy (sigh).


Ron N