Hammer rake angle, etc.

[Richard Brekne]

James Ellis wrote:

> Ladies and Gentlemen:
>
> The hammer may be perfectly perpendicular to the string on contact, but
> that does not mean that its crown in moving in that direction when it hits.
>  The hammer does NOT move in a straight line.  It swings in an arc.

I'll buy this

> The
> closer the pivot (the flange center) is to the string, the more nearly
> perpendicular the motion of the hammer's crown will be to the string at
> contact.
>

But I am not sure I will buy this. Lets see here.... The shank assembly is
pivoting on the centerpin, and regardless of where that is, when the shank
itself is vertical then it has at that exact moment no vertical component. If
the hammer was glued at 90 degrees to the shank then the same would be true for
the crown of the hammer. So it seems to me that if the crown is to hit the
string such there is no vertical component to its movement at the instant of
contact with the string then the shank would have to be vertical, the hammer at
90 degrees to the shank. If in addition one wanted the crowns momentum to be
applied perpendicular to the string plane, then the string plane would have to
be parallel to the shank.

Now I havent really thought about this before... at least not in these terms...
but the above condition doesnt really fit the idea of getting the center "as
close as possible" to the strings per se. The center from string distance
would have to be equal to the bore distance minus the horizontal distance
between the senter and the shank.


Or what ??? :)

>  It would be nice if we could put the
> hammer flange center right in the plane of the string, but we can't.  The
> plate and pinblock are in the way, so we compromise and do the best we can.

Pin block and plate aside... even if you could put the center on the same plane
as the strings... how would this be of any benifit ? For the crowns motion to
be perpendicular to the string at impact with the shank hinged on an axel thus
placed such that it would have to have a horrendous rake, or have a nearly non
existant bore length.

Ok.. so what am I missing here ? Grin... there has to be something.. yes ??

>
>
> Sincerely, Jim Ellis
>
> _--

Richard Brekne
RPT, N.P.T.F.
UiB, Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html