Capstans

[John Hartman]

Terry,

You will find the series of articles about capstan replacement in the first
three installments of "Piano Shop Trade Secrets". They appeared in the December
99, February 00 and the March 00 issues of the Journal. If you don't have these
you can contact the home office to buy back issues.

I was at the Arlington Convention to work at the Renner booth. I was not there
to present any of my classes.

John Hartman RPT

Farrell wrote:

> Hi John. I think you have addressed my main question regarding pressing
> capstans into a key - how do you grip the capstan and drive it straight? -
> you indicated that you use a "'chuck' out of 1/2" canvas reinforced phonelic
> rod (MSC #75963412571)." What is MSC #75963412571 (is the MSC a company?)?
> Can you provide any additional technical description of the characteristics
> of your machined taper (angle, depth, method, etc.)?
>
> P.S. Enjoyed your belly class @ Arlington.
>
> Terry Farrell
> Piano Tuning & Service
> Tampa, Florida
> mfarrel2@tampabay.rr.com
>
> ----- Original Message -----
> From: "John Hartman" <pianocraft@sprintmail.com>
> To: <pianotech@ptg.org>
> Sent: Monday, January 08, 2001 7:51 PM
> Subject: Re: Capstans
>
> > Del,
> >
> > In the March 2000 issue of the Piano Technicians Journal there is an
> > article I wrote about using the drill press to instal capstans. The
> > tapered "chuck" grabs the capstan with enough friction and is easily
> > made on a wood lathe. I have made a change in my procedure and have made
> > a new "chuck" out of 1/2" canvas reinforced phonelic rod (MSC
> > #75963412571). The same tapered hole is machined into the bottom. I got
> > this Idea from Ted Sambel and have used it successfully for reinstalling
> > capstans in old key as well as for new keyboards.
> >
> > Give it a try, it works great.
> >
> > John Hartman
> >
> > Delwin D Fandrich wrote:
> >
> > > From the information given, I'd guess an oversized pilot hole. Let me
> > > make a distinction here, as well. It is possible that a factory might
> > > successfully turn the capstans in place. This would be done with a
> > > machine that would precisely grip the head of the capstan holding it
> > > nice an true and then spin the capstan down with no side play on the
> > > capstan at all. This is not how we would do the operation in our
> > > shops. We take a capstan wrench -- of whatever type -- and slowly
> > > crank the thing down. They wobble all over the place finding their way
> > > down as best they can. By pressing, rather than turning, the capstan
> > > into a properly sized pilot hole, it is driven straight into the hole
> > > without much damage to the sides of the hole. I've tried it both ways
> > > and have consistently found those capstans I have pressed home to be
> > > straighter and tighter than those I have turned in. However, your
> > > mileage may vary.... If it works better for you to turn them home,
> > > then that it the proper way for you. We'll keep pressing on. Del
> > > -----------------------------------------------------------------------
> > >
> > >      ----- Original Message -----
> > >      From: Dave Nereson
> > >      To: pianotech@ptg.org
> > >      Sent: January 07, 2001 11:37 PM
> > >      Subject: Re: Capstans
> > >       I recently tried to regulate a brand-new Boston studio.
> > >      The capstans wouldn't stay regulated.  I'd regulate them,
> > >      then after tuning, there'd be too much lost motion again.
> > >      The capstans were being pushed down into their holes even on
> > >      a medium-hard blow, and no, I wasn't pounding the heck out
> > >      of it.  The factory must've a) drilled the holes too large,
> > >      or b) pressed, rather than turned them into their holes.  Or
> > >      maybe the holes expanded due to the dry Colorado climate
> > >      ?      --Dave Nereson, Denver
> > >
> >
> >