Knife Care Tips; Knife Blade Life; Cutting Stick; Bevel Angle - Challenge CHAMP 150 Operator's Manual

7.0 Knife Installation/Changing

7.3 Knife Care Tips

sharp, even after use. Keep the edge away from your body and keep the area clear of others when
handling knives. Never touch the cutting edge! To prevent personal injury and damage to the knife,
always keep knives in their holders with screws tightened. You are aware of the dangers, but others
may not be. Never attempt to hone, polish, or service the knife in any way. Failure to follow safety
procedures may result in severe lacerations or dismemberment.

7.3.1 Knife Blade Life

Knife blade life, or the time between sharpening, can be affected by many factors. One important
factor is the type of paper being cut. Abrasive paper, such as recycled paper, soft paper such as
newsprint paper, and bound books can all significantly shorten knife blade life. Also, if the knife depth
is set too deep, the knife will cut too deep into the cutting stick and can dull the knife blade.
A knife can last between 2,000 and 5,000 cuts before it needs to be sharpened. Cutting soft paper
(such as newsprint paper) or paper with high post-consumer recycled content can cause the knife to
need sharpening after only 2,000 to 3,000 cuts. Cutting pure paper, such as bond paper with no
recycled content, or hard paper can allow the knife to be used for as many as 5,000 cuts before it
needs to be sharpened. In all cases, the operator should continually check the quality of the cut to
determine when the knife blade needs to be sharpened. Some characteristics that indicate a blade
needs sharpening are:

The knife hesitates or stalls while making a cut.

The sheets are not all cut to the same length (usually the top few sheets are longer than the
rest of the sheets - this is sometimes called "draw").

Cut marks appear on the cut face of the paper.

The profile of the cut (side view) is not perpendicular to the table.

The cut does not appear straight when viewed from the top.

The knife makes a "rougher" sound as it passes through paper.

Nicks are visible on the cutting edge of the knife.

7.3.2 Cutting Stick

A worn cutting stick can affect the cut quality of the bottom sheets. When this happens, the cut stick
can be rotated. Usually, the stick should be rotated one or two times between knife sharpening.
There are 8 possible cut stick positions. The stick can be rotated 4 times, and then turned end to
end, and rotated 4 times again.

7.3.3 Bevel Angle

Challenge recommends that bevel angles for the CHAMP 150 knives be in the range of 21° to 23°. In
general, a 21° bevel angle will provide better cut quality when cutting soft paper (such as newsprint),
recycled paper, or bound books. However, 21° angle knives can become dull sooner than 23° knives,
F.150CH-O-A
! KNIFE SAFETY ! Knives are DANGEROUS!!! They are heavy and very
Page 22 June 2023