Leather Knob for Damper Frame Coil Spring

[David Love]

The method I had seen showed a  way to get the leather nicely wrapped over
the core.  It might have come from Baldessin, now that I think about it. 
Anyway, this is what I ended up doing.

1.  Cut a 3/8" plug and rounded off one end.
2.  Cut a piece of back check leather for covering the plug.
3.  Covered the plug with hide glue and put the leather over it.
4.  Squeezed the whole thing tightly into a closed end wrench (1/2") to get
the leather wrapped and clamped around the wood core.
5.  When dry a took the closed end wrench to the band saw and cut the
excess flush to the wrench making a nice flat bottom.
6.  Cut another piece of leather about 1" square and using a punch, punched
a 1/2" hole in it.
7.  Covered a small piece of fiberboard with hide glue and stuck the
leather covered knob onto the glue, then pushed the piece of leather with
the hole punched in it over the knob down to the fiberboard.  
8.  Let dry cut to size.  

This was for replacing the trap spring on a Mason Hamlin that sits at the
right end of the damper tray and tends to get noisy and apply uneven
pressure on the tray, with a coil spring positioned more directly over
where the dowel lifts the tray.  I do this frequently on Steinways when the
coil spring is located at the far left side.  On those I usually take a
forstner bit and sink a hole in the tray which I line with felt or thin
leather to hold the bottom of the spring.  I then cut off the old knob and
relocate it under the belly rail at a point near the dowel lift.  On this
piano, the distance from the tray to the belly rail is too long for the
coil springs I have, so I needed to make two knobs in order to get them the
proper distance apart.  

David Love
davidlovepianos@earthlink.net


> [Original Message]
> From: Bill Ballard <yardbird@vermontel.net>
> To: Pianotech <pianotech@ptg.org>
> Date: 10/2/2003 4:36:23 PM
> Subject: Re: Leather Knob for Damper Frame Coil Spring
>
> At 3:29 PM -0700 10/2/03, David Love wrote:
> >Some time ago I saw some instructions for how to make that leather
covered
> >knob that holds the Damper Frame Coil Spring in place on a Steinway.
> >Anybody know where I might find those instructions?
>
> I'd guess it would be:
> 1.) measure the I.D. of the coil and the thickness of your leather
> 2.) calculate what diameter a cylindrical "knob" would have to be to 
> have the leather flow down over it,
>     and still keep the leather within the coil's I.D. (Confirm this in 
> the bench.)
> 3.) make your knob (maybe, FR cardboard or felt punchings, punched again)
> 4.) glue everything up using the coil as a form for the leather on 
> the damper tray.
>
> Who's going to bet a quarter?
>
> Bill Ballard RPT
> NH Chapter, P.T.G.
>
> "Lady, this piano is what it is, I am what I am, and you are what you are"
>      ...........From a recurring nightmare.
> +++++++++++++++++++++
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