jig for Twisted-Key keytops

[Paul McCloud]

Terry:
    Right now I don't have any keytop replacement jobs pending, so all
this is just theoretical at this point.  The best way I can see is to
set the key in the jig with the old keytop still on.  The old keytop
surface is best reference, after all.  What I have been doing, so far,
is to put the keytop in the vise on the table, raise the table up so the
keytop rests against the planer (stopped, of course).  This sets the
height of the table.  I then remove all the keytops.  Next, I put a new
keytop without fronts under the key to be planed.  Then I shut the jaws
of the vise.  The new keytop automatically sets the proper planing
depth.  Sometimes, however, the jaws of the vise clamp the key unevenly,
and so the top surface gets planed at an angle.  This is not immediately
apparent, but when gluing the tops on, it sure is.
    Clamping the keys is a problem because the surface you need to put
pressure on to clamp the key is precisely the surface you're trying to
plane!  Clamping the sides of the key doesn't insure that the key is
flat on the table.  If you clamp the key on some other part from the top
will not insure the actual keytop surface area is still parallel to the
table.
    Which brings me to my original point.  That using the planer is a
manner similar to a jointer, with split tables (or fences, as on a
shaper) would be ideal.  This would mean, however, that the original
keytop would need to be left in place to be planed off.  Bad for
cutters/knives!  In my view, any other method is risky.
    What say you?
    Paul McCloud