Hammer spring replacement

Ken Jankura kenrpt@mail.cvn.net
Fri, 20 Aug 1999 10:37:26 -0400


At 08:38 PM 8/19/99 -0400, you wrote:
>Friends,
>
>Today I brought home a hammer spring rail which needs all the springs
>replaced.  It is from a 1980 Everett studio piano.  I'm sure information
>on how to do this is published somewhere.  Could someone please steer me
>in the right direction?
>
>Also, I was surprised that my magnet would not pick up springs that had
>broken off in the action.  I thought these springs were made of steel. 
>What _are_ they made of?
>
>Regards,
>Clyde Hollinger
>
I guess they're brass.  I've done a fair number of hammer return spring
replacements and find it easy and rewarding. Take off the cloth, clean off
the glue (steam or scrape), remove the old springs. For installation, the
key is using a piece of wire to insert through the loops as you first
install them to keep them from twisting out of alignment til you can route
the back end of the wire through the other hole, pull tight, and snip. To
restate a little clearer, insert the new springs in the holes, and as you
go, insert a piece of straight wire into the loop of the spring. If your
wire is as long as the rail, you can insert all the springs and they will
stay in place ready for the next step of securing the back end of the wire.
With practice, you can get the procedure down to a little over an hour or so.

One word of caution, on an action model I have measured a difference in
downweight of 17 grams between a spring with almost no tension and one with
maximum tension. They can make more difference to the touch than hammer
weight and center pin friction combined. I don't measure them with a
tension gauge, but somebody probably does. I usually eyeball the angle that
the old ones sat at at rest and try to duplicate. The newly installed
springs will sit naturally at a much stronger angle, so keep the straight
wire in the loops until you have bent them all down to where they should
be. Good luck.
Ken Jankura RPT
South Central PA Chapter
 
 


This PTG archive page provided courtesy of Moy Piano Service, LLC