thrust bearings are measured and packaged in sets – individual bearings may vary by as much
as .005 of an inch. Mixing them could damage the machine.
•Clean your material and machine thoroughly after each lapping operation. One grain of 80-
grit can scratch your material if allowed to mix with the next lapping operation.
•Never leave your flats on the lap plate when the machine is stopped for an indefinite period
of time. The can and will stick to the lap plate. Should you ever have this problem, add water
to the plate and start the machine. If the flat won’t come loose, jar it slightly with a block of
wood. Place the edge of the flat on the bumper ring when through with a lapping procedure
to avoid it sticking to the lap plate.
•After using the machine, when the machine won’t be in use for a day or so, put a thin coat of
oil on the inside of the plate. This will keep it from rusting.
•Never do fine (400g or 600g) lapping on a rusty plate. The scale from the rust will scratch the
surface of your material.
•Never overcrowd the plate. A 16” piece is the normal operating maximum for the 20” model,
Use the proportion should be followed in the other plate sizes.
LAPPING PROCEDURE
For a 24” Plate: With the machine running, pour about two (2) cups of 80-grit on the lap plate.
Add two (2) cups of water. Stop the machine and place material to be lapped on the lap plate and
start the machine. As the material begins the grind, the grit and water mixture will become a
creamy slurry. Maintain this creamy state throughout grinding process for maximum abrasion.
Note: Use equal amounts of grit and water to begin on all other plate sizes and lap into a
creamy slurry.
Always wash plate thoroughly between cycles to eliminate cross contamination of grits.
Testing for Flatness: Wash the piece off. Using an aluminum marking pencil, mark a 2” square
grid on the bottom of the piece. Replace the piece and lap for about 10 minutes. Remove piece
and examine the bottom. If the lines have been removed, the piece is flat and ready for the next
operation.
Second Lapping Operation: Once the material has been lapped flat on 80-grit, repeat the first
process using 220g and equal amounts of water.
Third Lapping Operation: Repeat the first operation using equal amounts of 400-grit and water.
Fourth Lapping Operation: Repeat the first operation using equal amounts of 600-grit and
water.
Polishing: Install the polishing pad, splash guard, and bumper ring. Start the machine and place
½cup of Cerium Oxide on the pad and add enough water to create a creamy slurry. Most objects
