23
Replacing Knives (Straight
Cutterhead Only)
Jointer knives are extremely
sharp. Use caution and proceed slowly when
working with or around the cutterhead.
1. Disconnect jointer from power source.
2. Remove the belt guard so that you can
rotate the cutterhead by turning the motor
pulley or by moving the drive belt. Do not
grab the cutterhead itself to rotate it.
3. Remove the old knives by loosening the
square head gib screws with an 8mm
wrench. See Figure 36. The springs in the
cutterhead will raise the knife for easy
removal. Remove knife and gib.
4. Clean the gib and the knife slot. Sandwich
the new knife and gib together and drop into
slot. Make sure the knife is oriented properly
in the cutterhead, as shown in Figure 36.
IMPORTANT: To position the knives for rabbet
cuts, take a shop scale with 1/32” graduations
and place it against the end of the cutterhead.
Slide the knife out until it is at the 1/32” mark on
the scale; that is, the knife will now be 1/32”
beyond the edge of the cutterhead. The gib
should remain in normal position, even with the
edge of the cutterhead. See Figure 37. This
adjustment will ensure that the knife clears the
end of the gib and cutterhead, and has good
contact with the workpiece. (See the “Operation”
section for further information on rabbeting
procedures.)
(NOTE: This same procedure can be used if a
small nick develops in the knives; simply stagger
the knives in the cutterhead to remove the effect
of the nick, without having to replace the
knives.)
5. The height and parallelism of the knife in the
slot, both for rabbeting and normal jointer
work, must now be set properly, to ensure
correct operation as well as minimize the
hazard of kickback. Refer to “Setting Knives
at Correct Height and Parallel to Outfeed
Table” on pages 18-21 for information on
adjustment and tightening procedures for
the knives.
Before starting the jointer,
make sure all gib screws are firmly
tightened. A loose knife thrown from the
cutterhead can cause severe or fatal injury.
Figure 36 (straight cutterhead)
Figure 37 (straight cutterhead)