Electric Chute Rotator for QA 42-A Snowthrowers
Here’s a project started over a year ago that I’ve finally finished and have installed and operating. Credit for this idea goes to Todd Markle (Farmall Gray) who thought of this idea first and discovered the motor and sprocket. The electric wiper motor is available from
www.surpluscenter.com and costs $18.95. It runs at 44 rpm, is reversible, continuous duty, and draws 1.5 amps at no load. Item number is 5-1367. A 12 tooth, #40 chain sprocket was purchased locally (Fleet Farm). The remainder of components were fabricated (motor mounting plate) or machined (sprocket hub).
Motor mounting dimensions were measured up and documented. A cardboard mockup of the mounting plate was then made.
It was desired to make this motor drive mount in the same fashion as the stock, manual drive sprocket assembly. Next, steel plate was then cut, drilled, and bent to form the motor mounting plate.
An adaptor was then turned on the lathe to form a shaft extension and to support the drive sprocket. In order to prevent the sprocket from eating into the slotted chute plate at the ends of the travel, a clutch needs to be devised. This consists of wave washers that press against the sprocket face, while allowing the sprocket freedom to rotate on the adaptor. At the end of rotational travel, the sprocket will slip on the adaptor as a function of the force that the wave washers exert. The amount of force, and thus slip torque, is adjusted by a bolt that threads into the adaptor. The components are shown below.
The complete clutch-sprocket-adaptor appears as follows:
The assembled motor assembly bolted right up to the snowthrower with plenty of clearance all around.
Another view of the motor assembly shows how nicely this fits together.
A double throw, intermittent-on toggle switch was mounted in an aluminum enclosure box and fitted to the hydraulic lift lever with clamps. This controls the direction in which the motor runs, and thus the direction that the chute rotates.
Wiring was routed in flexible wire conduit from the motor to switchbox, then from switchbox to battery. The installation looks cleaner than the original mechanical rotator rod and bracket.
I’m proud to say that it worked perfectly the first time out. 180 degrees of chute rotation (stop to stop) takes about 5 seconds. The initial guess at the slip torque adjustment seems about right. The complete rig looks like this from the side.
I will eventually draw up and dimension the special parts and make these available in the FAQ (or wherever the moderators would like them to be placed).
