[pianotech] wagner safety planer drill speed

[Paul McCloud]

These are very good points.  But, how do you know if the last guy to replace the keytops cut them evenly?  I'd like to see a system that indexes to the key TOP, which should be the most reliable surface.  Often the bushings are protruding from the front mortise which prevents the key from sitting down solidly on the table.  Of course, clamping the key in a vise eliminates that problem.  Another consideration is, in the case of clamping in a vise is whether the key is warped so that there is a deeper cut in the back end than at the front.  I have often considered a jig with a surface above the key that would be used while clamping in a vise.  That way, one could assume that the entire surface of the key would be evenly cut. 
As far as the sharpened bolt system is concerned, if one were to angle the clamp so that it provides some clamping force downward onto the jig, that might work better.  Or, use a swivel on the end of the piston, like are installed on C clamps, and glue some sandpaper on them to keep the key from sliding.  
Another idea I had is to screw the bottom of the key to a narrow sheet of thin plywood or plexiglas which would then be used to ride on the table. A couple of slotted rails could be made for the plexiglas sled to ride in and guide it past any cutter or router bit you like.  Add a stop to it so that you'd have a consistent cut length to match the keytop.  Make another jig to hold the key and plastic in position while the screws are inserted.  
FWIW.
Paul McCloud
San Diego

----- Original Message -----
From: "Jim Ialeggio" <jim at grandpianosolutions.com>
To: pianotech at ptg.org
Sent: Friday, December 7, 2012 6:10:16 AM
Subject: [pianotech]  wagner safety planer drill speed

Bill Monroe said:

< I made a different clamping mechanism which works better.
&
<My primary objective is to keep the key bottom flat on the sled. The 
sides of the keys are not an accurate reference to squareness from one 
key to the next, and therefore generally don't make a good clamping surface,


Good point, I never hear this issue discussed. Mostly I see setups which 
can't help but create an un-level-able set of keys, given the fact, as 
Bill says (my paraphrase), the  only reasonably trustworthy index is the 
key bottom.  Add to that the fact that the quill on most drill presses 
is so sloppy, that the planer head has to be moving around or at least 
vibrating in a way that in itself tends to create an inconsistent plane.

Still with Bill's setup, I can see how the pointed clamping studs would 
have a tendency to tip the key with some inconsistency, as the points 
contact the keys at points of varying density key to key. Its definitely 
an improvement over side clamping though.

I've done a few of the high end mineral plastic jobs on my own rebuilds, 
and though the job went well, and I did my best to index the bottom, I 
was not completely happy with the consistency of that top plane, either. 
I really think, the way around this is to have a final step where the 
keys are all assembled on the frame, clamped and then flattened out in 
that position, like they were before they were cut apart. Uhh...with 
something high tech like a belt sander or something. I don't however do 
this often enough to have put the time into solving this part of the puzzle.

Jim Ialeggio

-- 
Jim Ialeggio	
jim at grandpianosolutions.com
978 425-9026
Shirley Center, MA