Stow STR36SP manual How It Works Figure Condition a  Engine Idling, Clutch, Blade Pitch

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

Clutch

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.

The torque-sensitive pulley (Figure 26) utilizes a spring and cam. Peakperformanceresultsfromproperinteractionbetweenthedriven pulley spring and the ramp angle of the cam bracket.

STR36SP-SERIES— MAINTENANCE

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).

Matching Blade Pitch for Both Sets of Blades

Trowels equipped with optional Twin PitchTM 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.

1.Lift the pitch adjustment handle on either side. Once lifted, that side is now disconnected from the Twin PitchTM system.

2.Adjust to match the opposite side.

3.When adjusted, lower the handle to Twin PitchTM operating position.

A

B

SPRING

DRIVEN PULLEY

CAM

BRACKET

MOVEABLE	FIXED FACE
FACE

Figure 26. Pulley Spring and Cam Bracket

A	Twin PitchTM disengaged (one side)
B	Operating Position
	Figure 27. Pitch Towers

STR36SP- SERIES • RIDE-ON POWER TROWEL — OPERATION AND PARTS MANUAL — REV. #1 (09/16/11) — PAGE 31