Weber let off problem

[Steve Grattan]

bhendrik@flash.net wrote:
> 
> Two weeks ago I came across the following  problem.  On a routine
> tuning service call on a Weber grand, I noticed severe blocking of
> hammers due to inadequate let off.  Looking  back on my service
> record I had noted making let off adjustment two years previous. I
> contacted the Weber service represenative and he said to problem was
> due to "spreading action brackets".  It seems as though this is a
> problem that has cropped up on some Weber, Young-Chang, and
> Chickering grands  manufactured between 1989 and 1991.  He explained
> as best he could how to replace the action brackets.  I recieved
> yesterday the replacement brackets from the Weber company.  Since I
> have never come across this problem before, nor seen any write up on
> it in the PTG journal,  or have heard any mention from fellow piano
> technicians on this problem, I was hoping some of you who may have
> encountered this problem and replaced these brackets, could give me
> some pointers.  Bill Marciano did mention to replace the end brackets
> first.  He also mentioned "maintaining a .112mm spread."  I am still
> a little unclear as to what exactly this term "spread"  means.  Any
> suggestions would be appreciated.
>                            Bill HendricksonRPT
The spread dimension is the distance between the center of the center
pin on the hammer flange and the center of the center pin on the wippen
flange.  Set this at 112mm and then test the regulation.  Chances are
that you will be close and may only have to undo your adjustments of two
years ago.  Be sure to check the regulation thoroughly to be sure.
				Steve Grattan, Associate