Bechstein B hammer rake / more thoughts

[John Delacour]

At 15:32 +0200 22/6/08, ricb at pianostemmer.no wrote:

>...The design simply calls for the shank to be 3 mm higher at the 
>end of the shank then it would be if it was horizontal at impact. 
>Nothing like straight forward advice.
>...
>Following the above advice has worked out perfectly. Very easy to get
>close to a perpendicular to string orientation without draconian
>rakes.

Well, supposing the strings are horizontal right up to the top, which 
they can be in a Bechstein, and supposing that you make no allowance 
for facing and wear, then 'draconian' or not, the heads will need to 
be raked outwards 1.32 degrees.  If you allow for 1 mm. of lost 
length between boring and finishing, which is reasonable, then you 
will need to bore for an outward rake of 1.76 degrees.

JD