[pianotech] Key frame hold downs

William Monroe bill at a440piano.net
Thu Aug 13 18:36:08 MDT 2009


I understand the point, and it simply doesn't apply here.  How does one get
too much reverse crown?  Someone would have to be ridiculously aggressive,
sanding at the ends of the frame to create such a situation.  I'm not
suggesting one needs a bench vise to clamp the keyframe ends down
satisfactorily.  I'm just saying the key frame clamps did not hold the ends
of the frame down securely.  Kent Webb was somewhat involved in this and
agreed that the clamps were not the same as screwing in the cheek blocks.
This was done on new instruments at the factory, and while I didn't take the
frame out and measure the radius on the keyframe ([?]), I'm pretty confident
it was not excessive, nor were the pins bent, nor were there any other
anomalies that could be indentified.  The end result was simply that the two
methods yielded different results.

??  I'm not sure what else I can say.  As before, if it works for you,
great, full speed ahead.  I no longer use them as I don't have confidence in
the accuracy of that process.

William R. Monroe


>   >With the reverse crowned key-frame, you've simply got to have enough
> force to bring the ends of the frame into contact with the bed>
>
> That's my point William. If you have too much reverse crown or at too sharp
> an angle at the ends, Yes, it won't work.
>
> Al G
>
>
>
> All due respect, but no.  In my case, the frame was bedded well.  The
> clamps did not have enough force to bring the ends of the key frame into
> contact with the key bed.  That's just the way it was.  With the reverse
> crowned key-frame, you've simply got to have enough force to bring the ends
> of the frame into contact with the bed, and the clamps did not work well on
> the four pianos I tried them on.  As I said, YMMV and if you've found them
> to work for you, great.
>
> FWIW.
>
> William R. Monroe.
>
>
>  William R. Monroe wrote:
>> However, I personally don't recommend them, at least not for S&S ......
>> When I was in NY last spring, I tried a little experiment with them, and
>> they did not ACCURATELY replicate the pressure of the cheek blocks - and
>> this really is essential in S&S.
>>
>> If the key frame is bedded properly, they work great. If need to exert
>> that much pressure with the key blocks, you can be sure the bedding is not
>> right.
>>
>> Al G
>>
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://ptg.org/pipermail/pianotech.php/attachments/20090813/47848565/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/gif
Size: 96 bytes
Desc: not available
URL: <http://ptg.org/pipermail/pianotech.php/attachments/20090813/47848565/attachment.gif>


More information about the pianotech mailing list

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