Norton BBL547 Owner's Manual page 18

start "step cutting" - which means passing the material beneath the blade with
rapid , (50 to 60 strokes per minute) full length strokes, taking a shallow cut
(approximately 1/8" deep ) on the forward, and also on the backward stroke.
Complete each rapid stroke backward and forward, by passing the material
beyond the center of the blade before starting the reverse movement of the cart.
The harder the material, the more rapid the forward and backward strokes.
3. "Step cutting as can be seen in the sketch below, lessens the area of the blade
circumference in contact with the material, keeping the blade cool, running free,
and cutting at peak efficiency. Don't get the impression "step" cutting means slow
cutting - actually it is 6 times faster than trying to "force" the cut by strong-arming
the material through the blade. Forcing the blade through with a deep cut causes
a longer area of the blade circumference to be in contact with the material, causing
excessive friction heat to be generated, which then causes the blade to "smear"
or "load" with fused material particles and lose its sharp cutting surface. (Note: If
improper operation should cause an abrasive blade to "smear", make several cuts
through a soft brick to "dress" the blade back to good cutting performance.)
"Jam Cutting" and "Step Cutting" With Diamond Blades
C.
In "Jam" cutting the head is locked in a fixed position and the material is pushed
into it as shown in the sketch at the bottom. "Jam" cutting with the head locked in
a fixed position usually provides greater efficiency.
1. To lock the head into position, tighten the lever nut at the back of the saw.
2. "Step" cutting with diamond blades is done by applying more pressure to the
blade. Unlike "step" cutting with abrasive blades, "step" cutting with diamond
blades requires only a few passes through the material.
3. In cutting, clamp the material securely and hold it firmly against the conveyor
cart backstop. If the material is allowed to slip, resulting seizure of the blade may
bend the diamond blade steel center or cause a ring section to be twisted off.
4. Do not force the material or bump into the blade. When nearing completion of
the cut, retard and slightly hold back the conveyor cart. If this is not done, the
material may be pulled into the blade so fast that excessive pressure on the rim
may cause warping or twisting of the rim section.
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