"pulley" keys

[Richard Brekne]

Delwin D Fandrich wrote:

> ----- Original Message -----
> From: "Lance Lafargue" <lancelafargue@bellsouth.net>
> To: <pianotech@ptg.org>
> Sent: January 02, 2001 10:15 AM
> Subject: RE: "pulley" keys
>
> > Hey Del,
> > Maybe I'm confused about the goal and the ideal key/pin relationship.
> > Shouldn't the very bottom of the hole be _slightly_ larger than the pin?
>
> Not really. I would prefer to have the hole and pin size-on-size. That is,
> no free play whatsoever, but not binding either. When lifted slightly at the
> front and released, the key should just drop back in place or get there with
> just the slightest tickle.

If the key is too tight and will not fall into place you can experience key
leveling problems... ie the keys wont "stay" level.  The little buggers seem to
like to "climbe" the balance rail pin a bit and stay there... gets untidy...
causes regulation problems... no they have to slip down..

On the other hand any more then just enough to slip back into place can cause
all kinds of other problems... clacky action noises.. backcheck problems in
grands, accelerated wear on keybushings... and other things..

Ergo... "snug" is often the word used to describe the fit.

>
> > Essentially what you are doing with a traditional tool is forming a V
> where
> > the base of the V is slightly larger than the hole.

Why would you think this is the case ? Think about it for a bit... And if you
come in from the bottom when the hole is already contoured from the top,,, then
you actually are changing your "V" to a double "V"... with the points meeting.
Try coming in from the top the next few times you do this job. I think you will
find it easier to get consistant results

>
> > I am just coming in
> > from the bottom and exactly doing that leaving the upper portion alone.
> And
> > _if the upper portion is not effecting the key_, wouldn't that be the most
> > accurate way?
>
> Nope.

>
> Check the supply catalogs and look for a tool either made by Yamaha or
> copied from theirs. You'll see what I mean. You use it from the top.
>
> Del

--
Richard Brekne
RPT, N.P.T.F.
Bergen, Norway
mailto:Richard.Brekne@grieg.uib.no