[pianotech] Repeat of Question about damping problems with Steinway L

[erwinspiano at aol.com]

Very Nicely Done Jon.
?This is similar to my protocol as well. It's just that your's is?articulated more clearly than I could have done. grin.?A picture is worth a thousand words. I love pictures
? Thanks Dale



-----Original Message-----
From: Jon Page <jonpage at comcast.net>
To: pianotech at ptg.org
Sent: Tue, 30 Dec 2008 5:52 am
Subject: Re: [pianotech] Repeat of Question about damping problems with Steinway L



>As for the tray pin location...




When relocating the pivot in-line with the flange centers getting the new pivot

hole located in the support block is not difficult.




To maintain the forward location of the top flange there is a simple procedure.




With the tray and support blocks on the bench, measure from the back of the

support block to the old top flange center. (The tray should be parallel to the

bench or perpendicular if you place the backs of the support blocks on the bench).




Measure the distance between the new top flange and lever flange centers.

Subtract this from the previous measurement and that is the distance from

the back of the support block to drill your new hole. Ascertain first if the top

flange is situated well and the forwards portion of the lever is free.




To ascertain the height, it is equally as simple. This can be applied to original

back action modification to improve motion. Many times the lever is at too great

of a downwards angle to the key and scrubs a trough in the end felt; meaning

that the pivot center is too high.? There is the least sliding motion (friction)

when the lever is parallel to the keybed. There is no reason to have the

key elevate the lever beyond parallel because that introduces sliding

friction and crushes the back edge of the felt, counter productive.

Lifting to parallel is ideal.




On a Steinway, the key end felt lifts to ~1 3/4".

The distance from the bottom of the lever to the center is 3/8".

So for the lever to be lifted to that height and remain parallel to the bed,

the pivot height should be 2 1/8".




An easy way to setup the whole system on the bench is to measure

from the belly rail to the front of the keybed where the front of the

keyframe ends. Place masking tape at that distance on the bench

and locate the action and back action therein. You can worry about

a Magic Line but I don't think that it matters as long as there is proper

lift motion as mentioned above, especially way out at the end of the ke

and beyond.




I usually keep the same support blocks and screw hole alignment.

The new pivot hole will be forwards of the old hole, if it is too close to the

front edge, I'll shim the rear. If the new hole is too close to the old hole

then I'll cut a 1/4" plug from the lower, rear corner of the support block

and plug the old hole., can't get a better plug than that.

-- 


Regards,

Jon Page

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