Ratio question

[Richard Brekne]

Yes... and there is also a couple other things to keep in mind.  The 
action was designed (hopefully) for the key to be at a certain 
orientation (angle) at rest. For it to operate near its optimal then 
this should be maintained. You could for example easily raise the keys 
to get enough dip and end up with the capstan never actually passing 
through the center of its coincident arcs with the whippens movement.  
Ok... extreme example but you get my point.

Johns point about the front rail pin is a good clue.  The flip side of 
that is of course the key needs to be high enough to avoid the tip of 
the pin from contacting the underside of the inside of the key on a hard 
blow.  There is also the keyslip clue.

Get the proper key height for the action, and THEN set your key dip 
accordingly.

Cheers
RicB


             >There's room to raise the key height..yes I checked the
            sharps.


        Aside from making certain the sharps will not be affected by the
        fallboard there is a more important consideration. That is the
        depth of the front rail bushing on the pin. There should be at
          least 1/4" of the pin into the bushing at rest. Getting the
        key too
        high on the pin can cause accelerated wear from the end of the pin
        impacting into the cloth. In other words, the pin should be in as
        least as far as the depth of the cloth.

        So before you raise the key level, grip the f/r pin with tweezers
        at the bottom of various sharps and lift the key to see what is
        there.
        That info will inform you as to whether it is better to raise
        the keys
        or lower the dip. Adjusting the dip is much faster (lower cost) than
        to raise the level. Of course you have to consider the height
        of the key slip too.

        And around and around we go...

        Regards,

        Jon Page