Upright Action mounting pins

[Andrew and Rebeca Anderson]

---------------------- multipart/alternative attachment
Rex,
A lot of piano makers still mount the bottom of the action to the 
key-bed.  Some better ones (and one affordable Chinese make) have 
started mounting the action directly to the plate including the rear 
key-rest felt..  You see what happens with humidity flexing of the 
key-bed.  I've had actions shoved up where the last octave was 
striking on the upper string bearing (hammers were not incorrectly 
filed).  That is pretty rare, usually it's too low here.  Generally 
you like the feet tight.  But if it has been usually dry...you might 
think twice.
Typically strike point is most sensitive in the high 
treble.  Theoretically you want to strike on a seventh so as to 
weaken that partial most.  Typically you aim <= 1/8" below the upper 
bearing at C8.  If you can get good clean sound out of the piano, a 
little refining down lower might be possible.

Good luck and have fun,
Andrew

  At 03:14 PM 3/1/2006, you wrote:
>Hi, group!
>
>My name is Rex Burrus from Chicago and I'm new to the list and 
>recently new to piano technology having been indoctrinated by 
>classes of a local mentor and taken under the wings of the Chicago 
>PTG chapter early in 2005.  I've been tuning mainly, but also work 
>the technology angle of pianos, plus work on players for all of one year now.
>
>Now for my juicy question du jur...
>
>I have on two occasions come to wonder about action mounting in an 
>upright.  In both cases, I have found the action to be somewhat ajar 
>and not even settled upon the mounting pins in the keybed which have 
>made these pianos play lousy.  The one piano was completely cured 
>simply by repositioning the action properly and the customer was so 
>overjoyed that I made extra money on that tuning.  On my current 
>project, I found that the action is not properly resting on all the 
>mounting pins.  In fact the middle two pins are not even in contact 
>with the wells in the action supports.  These pins are threaded and 
>squared so that turning them moves the mounting pins up and down in 
>the keybed.  I suspect that at another time, some "tooner" ran into 
>trouble seating the action and at a minimum raised the treble end as 
>the treble hammers were striking the v-bar and making no sound.  So, 
>minimally, I'll lower the far upper mounting pin and this should 
>cause all mountings to fall into proper alignment.  Intellectually, 
>I'm wondering overall what any procedure might be to precisely 
>locate an action using these mounting pins.  I understand that 
>raising or lowering the action changes the striking point of the 
>hammers on the speaking length of the wires, so I'm curious as to 
>how the striking point is found or if there are any good references 
>on this, and what might be a proper procedure for adjusting 
>(regulating?) the mounting pins in the keybed of an upright?  Is 
>this a factory only adjustment?
>
>Thanx!
>
>PIANO TUNING by REX!
>Repairs and adjustments, also.
>(708) 418-0750
><mailto: teslaspark@aol.com>teslaspark@aol.com


---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/92/d5/c7/02/attachment.htm

---------------------- multipart/alternative attachment--