[CAUT] Down Weight Too High With New Hammers

[Paul Milesi, RPT]

Oops!  Thank you, Jon!  Yes, I forgot to divide by 2.  :)

No, the original wip centers are quite loose ‹ teflon ‹ and hence my
conclusion that the friction is actually at the cushion-capstan contact.
Like I said, the new cushions are centered about 1mm forward compared to the
originals.  Also, the original cushions are very worn from excessively hard
play, and I¹m thinking that¹s what¹s causing the variations and lack of
smooth movement as keys are depressed.  I¹ve eliminated key friction as a
culprit.

What¹s an acceptable range for BW?

If I can¹t get new repetitions, is it worth trying to bolster cushions or
can they be easily replaced?

I haven¹t measured FW.  Need to set up a jig of some sort?  Unless I can fit
my little digital gram scale under the front of the key with it still on the
balance rail?  I need to learn more about that...downloaded and read 3 of
Stanwood¹s articles, but I¹m far from a master yet.

Thanks again, Jon.
-- 
Paul Milesi
Registered Piano Technician (RPT)
(202) 667-3136
(202) 246-3136 Cell
E-mail:  paul at pmpiano.com
Website:  http://www.pmpiano.com




From: Jon Page <jonpage at comcast.net>
Reply-To: <caut at ptg.org>
Date: Sat, 18 Sep 2010 12:51:37 -0400
To: <caut at ptg.org>
Subject: Re: [CAUT] Down Weight Too High With New Hammers

> Note           DW  UW  F   BW
> F69-orig rep    69  33  36 102
> F69-new rep     57  33 24   90


The math for figuring F & BW:
(D - U)/ 2 = F
(U + D)/2 = BW

You forgot to divide by 2.

Orig should be:  18  51
New                   12  45

Friction is OK with the new but the BW is still too high.
Seems like a drastic chance for just changing wips.
Were the old wip centers on the tight side?

What's the FW?
-- 

Regards,

Jon Page


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