Motors for Haunt and Halloween Props

There has been a lot of talk about the shortage of electric motors for Halloween prop building since the supply of surplus wiper motors and vent motors has dried up.   For the January meeting of CalHaunts I put together the equivalent of a 10th grade science project to demonstrate some potential haunt prop motors.   After visiting all the usual sources of surplus parts (That post is coming) I gathered what I thought were the best candidates for electric motors to build into props.  Most are 12 volts and less than $20 dollars for the motor.

The benchmark project in mind was the classic Flying Crank Ghost.  Motors needed to be strong enough and slow enough to replace the $50 motor specified by phantasmechanics.

What we ended up with was 7 motors that seem to be good prop building candidates.  Six motors are 12 volts and one is 110 AC.  To demonstrate the available torque I modified each motor to accept a 6" crank arm and tested it using an 8 once weight.

To deal with motors with high RPM, I demonstrated two inexpensive PWM modules available from ebay.com to control motor speed.  (More information on Pulse Width Modulation controllers in a later post.)

Over the next few days I'll do a more detailed post on each motor.

Note:  Thanks to Dennis Griesser (of Wolfstone fame) for these photos and all the closeup photos of motors to come.  (Dennis - Could you please Photoshop away 20 pounds from me next time?)

PWM Controller for DC Motors

PWM DC Motor Speed Control 

Ebay.com
Seller: t-mall
Price $9.99 including shipping from China
Search for: PWM DC Motor Speed Control 6A AMP 12-24V VOLT 13KHZ Controller Switch

 

For our purposes, a Pulse Width Modulation (PWM) controller allows you to dial in the speed of a DC motor.  This allows you slow down a high speed motor such as a wiper motor to power props at a lower speed.  For a technical explanation see the Wikipedia article (http://en.wikipedia.org/wiki/Pulse-width_modulation)   Basically you can slow down a motor without losing much torque or wasting power using a controller like this.

 

I just tested this PWM unit as was very please with results.   Wiring was a snap and this unit did not cause the motor to buzz annoyingly.  There was a high pitched noise on one of the motors tested but the volume was low.

 

Adding the module is very easy.   If you go with the usual convention that a motor is wired with the red (+) wire to the motor and the black (-) wire to ground of the motor.  Red to red, Black to black.  The PWM module adds one wire to the mix.   Now you connect the red motor to the red power wire and the red wire from the module.  Essentially you wire the red wire to both units.   The negative wire from the power source goes to the black wire of the module.   Now the blue wire from the module connects to the "-"  connection of the motor.   Actually the picture on the module does a better job explaining what to do...

 

At ten bucks adding a PWM module makes your prop motor much more controllable, allowing you do dial in the speed of your prop exactly.

 

I've tried some cheaper, 7 or 8 dollar controllers that cause a loud buzzing noise in the motor.   This one does not.   I will be testing several other controllers in the near future.