[pianotech] Brumbach Rebuild

[Mike Spalding]

Paul,

If you haven't done it already, measure the down weight, up weight, and 
action ratio, and let us know what they are.

thanks

Mike

On 11/1/2010 2:58 PM, Paul McCloud wrote:
>
> Hi, Friends:
>     I've got a Brumbach action that someone rebuilt some years ago.  
> The pear shaped knuckles are now the standard type, and new hammers, 
> shanks and whippens are fitted.  The capstans are relocated closer to 
> the balance rail.  The customer's complaint is that some of the keys 
> are sluggish to return.  After removing the action, I discovered that 
> jiffy weights are mounted under the keysticks just behind the front 
> rail.  This is in addition to the leads in the keys.  As it is, the 
> keys play ok except for a few in the bass which is where the 
> troublesome notes are.  What I'm seeing in the action setup is that 
> the capstans are set too high.  The top of the capstans is above the 
> "magic line".  If you observe the capstan/heel contact point, you can 
> see quite a bit of sliding as you press the key.  Since I am not 
> normally set up to rebuild actions and do all of the balancing work, I 
> wondered if someone could ex plain how I would go about rectifying 
> this action.  My instinct tells me that the heel should be 
> taller/longer, and the capstan lowered so that they meet at a point on 
> the "line".  What I don't know is if this will solve the problem or 
> just lead me down a blind alley with more problems awaiting.  I don't 
> have downweight/upweight measurements because I misplaced my gram 
> weights somewhere.    I also noticed that the jack and knuckle are at 
> a bit more of an angle than I'd like to see.  I wish I had the parts 
> kit from Renner or Tokiwa to try some different combinations.
>         Interesting that this piano belonged to the late John Lennon, 
> and he wrote "Imagine" on it.  The owner says John purchased it in New 
> York.  I'm not sure if the work was done before John purchased it, or 
> later.
>     Any suggestions or advice are much appreciated.  I do have more 
> photos if needed.
>     Paul McCloud
>     San Diego
> pmc033 at earthlink.net <mailto:pmc033 at earthlink.net>
> EarthLink Revolves Around You.