Shanks parallel to strings

[Phillip Ford]

I would like to revisit the idea that shanks should be parallel to strings at hammer contact.  I know we've had some discussion of this before.  I looked back through the archives and also in the back issues of the Journal and couldn't really find what I wanted.  I would like to have some theoretical reasons why having the shank parallel to the string gives better action performance than not having it parallel.  The standard thinking seems to be that the hammer should be perpendicular to the string line at contact and the hammer should be perpendicular to the shank, which results in shanks parallel to strings.  I can see reasons for having the hammer strike perpendicular to the string line.  But I don't see any good reason for having the hammer perpendicular to the shank or the shank parallel to the string.  Reasons given in the archives or the journal for not permitting non-parallel shanks are along the lines of:

1.  It's bad practice.
2.  It reduces power delivery.
3.  It won't give as strong a joint at the hammer to shank interface.
4.  The regulation will get screwed up.

As to these reasons:

1.  If it's bad practice, is there some explanation on offer?
2.  Why would it reduce power delivery?  The hammer is still traveling in the same path as it was before - the angle of shank to hammer doesn't affect that.  If the hammer is still striking perpendicular to the string why would any reduction in power have occurred?
3.  I don't see that the joint should be weaker.  If anything, having the shank not perpendicular to the hammer would mean that the hole through the hammer has to be a little longer, which would seem to result in a stronger glue joint.
4.  I can see that this would be true if the action was designed to work with the shank parallel at contact, and that drastically changing this would cause various things like rest rails and letoff buttons to be in the wrong places for the new shank position.  But I'm talking about an action that was specifically designed to have the shank non-parallel at contact.  In this case everything could be positioned to work properly so that regulation would not be compromised.

Any thoughts?

Phil



Phillip Ford
Piano Service and Restoration
San Francisco, CA