[pianotech] Puzzler 10/26/09

[piannaman at aol.com]

 Jack catching on getting pinned on jack stop rail?

 

Dave Stahl
 

 

-----Original Message-----
From: John Formsma <formsma at gmail.com>
To: pmc033 at earthlink.net; pianotech at ptg.org
Sent: Wed, Oct 28, 2009 7:39 am
Subject: Re: [pianotech] Puzzler 10/26/09









Nope, nothing to do with the grommets.  But I did correct the extreme lost motion in my first attempt to remedy the problem. Didn't help at all. After I'd fixed the real problem, the hammer was about 1/2" off the rail. So I had to undo the lost motion "adjustment."



Go below the keybed in your thinking ... <G>


--
JF


On Wed, Oct 28, 2009 at 8:55 AM, pmc033 at earthlink.net <pmc033 at earthlink.net> wrote:









Ok, John, I'll take a stab (nobody else I can see has a reply).


The rubber grommets that connect the end of the key to the sticker wire are hard from age.  Somebody noticed that there was too much lost motion and used that square tool to take up the slack.  The grommet hardened with the keystick/wire at a certain angle, so that when the grommet is turned for adjustment the grommet is putting pressure on the keystick causing it to bind on the keypins.  If you remove the sticker wire, the key is free to move.  Connect it, and you'll get binding on the keypins.  



    If there are no rubber grommets, similar situation with the sticker wire- somehow it is binding on the key and not allowing it to move freely, though when it's disconnected the key moves freely.



    Am I close?


    Paul McCloud


    Sa nDiego


 







 




----- Original Message ----- 


From: John Formsma 


To: Pianotech List


Sent: 10/27/2009 8:21:33 PM 


Subject: [pianotech] Puzzler 10/26/09




Was working on a 1971 Currier spinet yesterday, doing a 100+ cent pitch raise and minor repairs. (Yes, icky work, but bills is bills.) F6 wasn't repeating at all during the first pass, so I took some time to figure what was wrong. The note would play once and not repeat unless you really hit the key quite hard.





The jack was the problem. It didn't return under the hammer butt ... much like when the jack spring is weak/broken or the flange is too tight.  But neither of those were the problem.






Key friction wasn't the problem. Wippen friction wasn't the problem either, although I certainly didn't remove the action to check it. :-)






What I found puzzling ended up being the clue to solving the problem: lost motion was considerably greater than any of the neighboring keys.





Some tools involved in the repair were a Reyburn CyberHammer and a 8" action screwdriver bit (the one with a reduced shank for flange screws). WARNING: the previous sentence will not lead to the solution. It is given only to confuse and bewilder you. Pictures will follow that demonstrate that the repair tools were ones used out of necessity. <G>







Good luck!



-- 
JF















 

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