Building a Wiper Motor Rocker Halloween Prop
We started this build with a rocking chair that we've had for more than 19 years. It's old and weathered and sorta creepy on its own. But a decomposing old woman rocking away will be a lot more interesting. One of the things we did not want to do was to make the chair unusable after Halloween. So the prop is self contained and removable for storage and does not damage the chair.
A wiper motor is needed for this prop. We already had a 12VDC wiper motor that was purchased a couple of years ago. The one pictured is no longer available but Monster Guts sells a similar one. We also needed about 4-feet of 2x6 pine board which forms the base of the unit.
We used Scary Terry's technique of using a 4x4 post cap and a couple of brackets to create a mount for the wiper motor. The motor is secured with 6mm screws.
Wiring is attached to the motor and a quick connect jack. We used the low speed connections as described on Scary Terry's web site.
Here is the hardware connections at the motor. We used a 1/4 inch bolt with a lock washer and nut on the motor arm followed by a washer then the crank arm then another washer and finally a lock nut. The bolt must be tight against the motor arm but the outside lock nut must be loose enough to allow the crank arm to move freely.
The other end of the crank arm is attached 8.5 inches from the top of the torso section using a 1/4 inch lag bolt and two washers. This connection must also be loose enough to allow the crank arm to move.
Four pieces of 1 inch PVC pipe and two 90 degree elbow fittings were used for the shoulders and upper arms. A couple of pieces of foam from a pool noodle add some bulk to the arms. The styrofoam wig head will be covered by a mask.
Video of Wiper Motor Rocker in Action