Today I finished the pallets. Because of the prior thinning, they were rough, and I smoothed them with first 240, then 600,1200 and 1500 grit carbide sandpaper. To help out, I used a piece of dowel stick sharpened in a pencil sharpener as a handle to hold the pallets through their hole against the sandpaper. I also used emory sticks, which seem to do a good job. It's important for the working surfaces of the pallets to be quite smooth -- to reduce wear on the escape wheel and to reduce friction.
I also used a jig to polish the lifting surfaces -- the inclined parts. This is the jig that I used originally to make the 45-degree angle of the lifting surfaces. (At that time, I had no camera.)
Basically, the pallet blank is screwed to a board which has a 45-degree cut in it made with a table saw. The board also has a small shelf at the bottom, upon which rested the original bottom of the pallet blank, now sawn away. The tips of the pallets extend above the surface of the board about 1/16", so they can be worked. Before the origial bottom of the pallet blank was sawn away, I marked the ark of the pallet body on the board so that the pallets could be put back on the jig in the original position for polishing, which is what I'm doing now.
The lifting surfaces were originally ground to the 45-degree angle with an Arkansas stone. Now, however, I used a fine emory stick. The stick and the stone roll on a roller, the material of which is as thick as the .height of pallet nibs above the top of the board. The angles on the pallets incline in opposite directions, so you must unscrew the pallets and reverse them on the jig to do both nibs. It's possible to make the incline in the wrong direction -- I did that once!
After polishing, the pallet nibs were heated redhot and quenched, one at a time. Only the nibs were hardened. Pallet nibs are left fully hard, without any furter heat treatment. After hardening, the pallets were again given a light polishing to remove the discoloration from heating.
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