General 90-170B M1, Setup & Operation Manual, Page: 18 / 32

ADJUSTING THE UPPER / LOWER BLADE GUIDES ASSEMBLIES
The guide bearings A keep the blade from moving from
side to side during cutting and must be snug but not
touching the blade in order to ensure accurate cuts. The
space between each guide bearing and the blade must
not exceed 0.02" (the thickness of a sheet of paper). If less
space is left, the blade will get stuck or jammed between
both bearings. Too much friction will cause blade to over-
heat and break.
Also, the guide bearings must remain at least 1/32” be-
hind the blade teeth to prevent damage to the blade
B .
The thrust bearing C keeps the blade from moving back
and out of position when the work is being fed into the
blade and must be very close to the back of the blade to
prevent damage to the blade during cutting.
Note: Before adjusting the upper and lower blade guides assemblies, make sure the blade is tensioned and tracking prop-
erly. Adjust the upper and lower blade guides assemblies after each blade tension and tracking adjustment. Whenever the
upper guide bearings and thrust bearing are adjusted, the lower guide bearings and thrust bearing should also be adjust-
ed.
TO AVOID INJURY, MAKE SURE THAT THE POWER SWITCH IS IN THE “OFF” POSITION AND THAT THE POWER CORD IS
UNPLUGGED BEFORE PERFORMING ANY ADJUSTMENTS ON THE BANDSAW.
Adjust the positioning of the upper guide bearings:
1. Using the supplied 3 mm Allen key, loosen set
screw,
A.
2. Use a flat head screwdriver to make a quarter of a
turn (approx.) toward the inside to the guide bearing
B , to obtain a space of 0.02" (the thickness of a sheet
of paper) between the bearing and the blade.
Tip: Place a feeler gauge
C
or sheet of paper between the
bearing and the blade to make sure there is a 0.02" space.
3. Re-tighten set screw A to lock the guide bearing in
position.
4. Repeat steps 1 to 3 with the other upper guide bear-
ing.
5. Loosen the lower thumb screw D .
6. Move the upper guide bearing shaft in or out E until
the guide bearing are at least 1/32" behind the
blade teeth, (do not protrude past the hollowed part
of the teeth of the blade
F
.
7. Re-tighten the lower thumb screw D .
1/64"
0.02"
0.02"
A
C
A
B
C
1/32"
B
E
F
Adjust the positioning of the upper thrust bearing:
8. Loosen the upper thumb screw G .
9. Move the upper thrust bearing shaft in or out H
until the thrust bearing barely touches the blade (is
1/64" behind the back of the blade
I ).
10. Re-tighten the upper thumb screw G .
G
H
I
Adjust the positioning of the lower guide bearings and thrust bearing:
Repeat steps 1 to 10 with the lower guide bearings and thrust bearing.
18
1/32"
D