Ryobi BS901 Operator's Manual page 13

ADJUSTING BLADE TENSION
See Figures 10 and 11.
Turn off and unplug the saw. Remove the switch key.
WARNING:
Failure to turn the saw off, remove the switch key, and
unplug the saw could result in accidental starting causing
possible serious personal injury.
Before using the band saw, turn the blade tension knob
on the top of the saw clockwise to engage tension. See
Figure 10.
To check tension, raise the blade guide assembly all the
way up to expose the blade.
Push the blade to the side with moderate force; the blade
should flex approximately 1/8 in. (3 mm).
Note: Adjustments of blade tension can be made at any-
time.
Another method of checking blade tension has to do with the
sound the blade makes when plucked like a guitar string.
Pluck the back straight edge on the coasting side opposite
the blade guides while turning the tension knob. Sound
should be a musical note. Sound becomes higher pitched
as tension increases.
Using either method to check blade tension can be developed
with practice.
Never increase blade tension so tight as to completely
compress the spring. When completely compressed, the
spring can no longer act as a shock absorber.
Note: Too much tension may cause the blade to break. Too
little tension may cause the blade to slip on the wheels.
TO DECREASE
TENSION
BLADE TENSION KNOB
TRACKING THE BLADE
See Figure 11.
WARNING:
Failure to turn the saw off, remove the switch key, and
unplug the saw could result in accidental starting causing
possible serious personal injury.
ADJUSTMENTS
BLADE ON
WHEEL
Note: Adjust blade tension properly before making tracking
adjustments. Check that the blade guides are not interfering
with the blade.
To Adjust:
Open the front cover by releasing the upper and lower
latches. Watch the blade's position on the upper tire
through the tracking view window as, by hand, you slowly
TO INCREASE
turn the upper wheel clockwise. If the blade moves away
TENSION
from the center of the tire, the tracking must be adjusted .
If the blade has moved left or right of center:
Turn the blade tracking knob (clockwise if blade has
moved left and counterclockwise if blade has moved right)
while turning the wheel by hand until the blade moves
back and rides in the center of the tire .
Fig. 10
Check the position of the blade on the lower tire. The
blade should be completely on the tire. If not, adjust the
tracking until the blade is on both tires.
Rotate the upper wheel by hand in a clockwise direction
for a few more turns. Make sure the blade stays in the
same location on the tires. Readjust, if necessary, until
blade is tracking properly.
Close front cover and relatch.
Note: The 1/8 in. (3 mm) blade may not track properly in the
center of the wheel. It may be better to track this blade on
the back half of the upper wheel.
Page 13
BLADE
TENSION
KNOB
Tracking
View
Window
TRACKING
VIEW
WINDOW
BLADE TRACKING
KNOB
Fig. 11