[CAUT] Re: Petrof Wippen Rail

[James Ellis]

I'm a little concerned about some of the suggestions being tossed around
here.  Someone said raising the back action bracket feet would not affect
the "magic line" through the capstan/wippen-heel contact.  Oh, but it will!
 Someone else suggested raising the front of the wippen rail, and tilting
it.  Why?  If you just tilt the rail backward, but otherwise leave it where
it is, it will change the magic line a little but, but it will screw up the
action spread a lot more, pull the wippens back, and you'll end up with a
bunch of broken jacks if you aren't careful.  Raising the back of the rail
and tilting it forward would do the opposite.  But why tilt the thing in
the first palce?  I can't see it.

Here's my suggestion for anyone who has a good knowledge of action
geometry.  Just use your own good common sense, and forget all those "quick
fixes".  They may be appropriate, but they may not.  Unless that "magic
line" is way off, and the capstans are rough, it's not going to amount to
very much anyway.  If it all lines up at some point during the key stroke,
it may not be ideal, but it won't be very far off either.

I'm not nearly as concerned about an actual measurement of action spread as
I am about where things are.  Look at the positions of the jacks in the
balancier windows, and where they end up on a hard firm blow with the key
bottomed out hard.  If they are slammed up against the felt at the fronts
of the windows, you are in trouble, and can expect broken jacks.  If the
jacks end up wedged between the knuckles and the balancier windows when the
key bottoms, you can expect jamming repetition.  If the tops of the jacks
are still a mile away from the fronts of the windows when the key is
bottomed out hard, you can expect occasional skipping and cheating on fast
repetition.

Sincerely, Jim Ellis