Multiquip STR36SP - Manual (Page 31)

STR36SP- SERIES • RIDE-ON POWER TROWEL — OPERATION AND PARTS MANUAL — REV. #1 (09/16/11) — PAGE 31
How It Works (Figure 25)
Condition A:      Engine Idling

    Drive Pulley: Small

    Driven Pulley: Large

    Belt: Loose and Stationary
Condition B:      Engine Accelerating

    Drive Pulley: Small But Increasing

    Driven Pulley: Large But Decreasing

    Belt: Approaching Tightness
Condition C:      Engine At High Speed

    Drive Pulley: Large

    Driven Pulley: Small

    Belt: Tight
The torque-sensitive pulley (Figure 26) utilizes a spring and cam.
Peak performance results from proper interaction between the driven
pulley spring and the ramp angle of the cam bracket.
DRIVEN PULLEY
FIXED FACE MOVEABLE
FACE
CAM
BRACKET
SPRING
Figure 26. Pulley Spring and Cam Bracket
STR36SP-SERIES— MAINTENANCE
Trowels equipped with optional Twin Pitch TM Controls may need
to have blade pitch between the two sets of blades "syncronized".
If the blades need to be syncronized this is easily accomplished
by performing the following. Refer to Figure 27.
Blade Pitch
Sometimes it may be necessary to match blade pitch between
the two sets of blades. There are some signs that this may be
necessary. For example, the differences in pitch could cause a
noticeable difference in finish quality between the two sets of
blades. Or, the difference in blade pitch could make the machine
difficult to control. This is due to the surface area in contact with
the concrete (the blade set with the greater contact area tends to
stick to the concrete more).
This clutch system provides a high pulley ratio (a low gear- so to
speak) to start out and a low pulley ratio (a high gear- so to
speak) for a high speed operation, with infinite variation between
the two.
This means that it will not be necessary to give full throttle in
order to "break the blades/pans loose". The machine can slowly
be brought up to speed.
Clutch
Figure 27. Pitch Towers
Matching Blade Pitch for Both Sets of Blades
A Twin Pitch TM disengaged (one side)
B Operating Position
A
B
1. Lift the pitch adjustment handle on either side. Once lifted,
that side is now disconnected from the Twin Pitch
TM system.
2. Adjust to match the opposite side.
3. When adjusted, lower the handle to Twin Pitch TM operating
position.