Bore lengths

[Richard Brekne]

Hi Ed

This is what I usually do, almost. I have a small double square that 
allows me to square the hammers to the strings.  I remember reading your 
post on this about 3 years back and made my self a nice selection test 
hammers to do this.

In this case, measuring this way agreed very well with the results I got 
from using the string height to keybed measurement with the action in 
the piano.  I havent been back to look again today, but something about 
this Petrof has to explain the difference between <<in piano>> and <<on 
bench>> measurements using the string height method.

Cheers
RicB



A440A@aol.com wrote:

>Greetings, 
>       I have a variety of bore lengths in a set of trial hammers.  These 
>have a centerline inscribed on both sides. they are mounted on shanks at exactly 
>90 degrees.   I put them in the action, reinstall the action, lift the trial 
>up to the string,(damper is removed for this), and put a small square on the 
>string to see what bore length gives me a 90 degree angle upon contact with the 
>string.  If the piano is going into a heavily used venue, I will often add a 
>mm or two to the length so that the longevity of the hammers usefulness is 
>increased. 
>    This method sidesteps the fact that strings are not always parallel to 
>the keybed,(particularly in the top sections of Steinway grands.)  Sometimes, it 
>would be necessary to bore longer than there is room for in order to make 
>everything 90 degrees, so then a few degrees deviation from 90 on the hammer 
>shank allows the hammer to strike the string at 90 degrees and still be able to be 
>regulated. 
>Regards, 
>
>
>  
>