[pianotech] Hammerheads resting on Backchecks when hammer is atrest

[George F Emerson]

Before anything else, I would make certain that the action is located 
correctly, front to back.  In some cases there is room for a slight shifting 
of the action.  Clearly, the action stack had been removed to bush the keys, 
and there is the possibility that it was not replace in the correct 
position.  You can double bent the back check wires to get them in the right 
relationship to the hammers, front to back, but make sure the hammers are 
where they belong first.

Frank Emerson

----- Original Message ----- 
From: "David Ilvedson" <ilvey at sbcglobal.net>
To: <pianotech at ptg.org>
Sent: Monday, April 19, 2010 3:08 PM
Subject: Re: [pianotech] Hammerheads resting on Backchecks when hammer is 
atrest


>I would regulate the blow distance, letoff/drop to specs.   Then check that 
>the hammers are checking properly, i.e. the backcheck not to close to the 
>hammer tail.  When hammer is moved through letoff/drop the top of the 
>backcheck should be just a little bit below the hammer tail.   Since you 
>are not going to do any big repairs such as lower backchecks, if that was 
>the problem, I'd make the hammer blow a little closer that spec to solve 
>the problem.   You don't want the hammer touching the backcheck at rest.
>
> David Ilvedson, RPT
> Pacifica, CA  94044
>
> ----- Original message ----------------------------------------
> From: "Mark & Janine Davis" <pianofortetechnology at saol.com>
> To: pianotech at ptg.org
> Received: 4/19/2010 11:29:36 AM
> Subject: [pianotech] Hammerheads resting on Backchecks when hammer is at 
> rest
>
>
>>Greetings List
>
>>
>
>>I am needing to regulate an old C. Bechstein grand which has had some work
>>done on it in the not so distant past.  The grand is about 100 years old.
>>What I plan to do is 1. Lubricate, 2. Align, 3. Regulate/Adjust wherever
>>necessary as best as possible.
>
>>
>
>>One thing I am not sure of is the hammerheads are resting against the
>>backchecks when at rest, even to the point that if you push the backcheck
>>away from the hammer, the hammer drops back down onto the rebound cushion.
>>I am aware that the hammerblow needs to be set and that by doing this the
>>shanks will be held up and off the rebound cushion and that the capstans
>>will need to be adjusted in order for this to take place.
>
>>
>
>>The little experimenting that I have done is to check if the hammer still
>>rests against the backcheck even when the capstan is adjusted so the 
>>hammer
>>is being held up and off the rebound cushion by the wippen/repetition
>>lever/jack and not by the backcheck, but the hammer is still resting 
>>against
>>the backcheck.  This problem is in the middle and bass sections of the
>>piano, the treble does not seem to have this problem.
>
>>
>
>>The piano action with the keys and keyframe were removed from the piano 
>>and
>>brought to me after the keys were rebushed.  I do not know what the
>>situation will be once the hammerblow is worked out and adjusted for at 
>>the
>>piano.  I do not think that it will be different?
>
>>
>
>>Are the hammers resting against the backchecks a problem?  And if so, how 
>>do
>>I sort it out?
>
>>Your advise will be much appreciated!!!
>
>>
>
>>Thank you,
>
>>Best regards,
>
>>Mark Davis
>
>>