Using a Windshield Wiper Motor

Windshield wiper motors turn out to be a very good, relatively cheap and easy motor to use to animate props. There's a lot of different how-to's out there telling you how to use them. Scary Terry is one I use a lot http://www.scary-terry.com/wipmtr/wipmtr.htm. Lately the motors mentioned there are getting harder to find. I've started purchasing this wiper motor from monsterguts.com instead: www.monsterguts.com. Here are the ways I've used to power the motors, mount the motors and replace the crank arm. Let me know if I need to elaborate on anything in this little how-to (jeff.a.baird(AT)gmail.com). This how-to is a work in progress, which means I need to add a lot more pictures and probably elaborate on some of my steps. But it should be a good start.


Mounting the Motor

Parts & tools I use:
  1. Simpson Strong-Tie (2-3/8") Fence Mount - $2 at Lowe's and Home Depot
  2. Grabber screws
  3. 2x4 to attach the motor to
  4. Philips Screwdriver or drill with philips head bit
  5. Hot glue gun


We found a U shaped metal mount at both Lowe's and Home Depot for holding a fence post. It also works great for holding a windshield wiper motor. It comes with a screw to tighten it around the motor, but it doesn't appear to keep things tight enough. The motor can wiggle and turn a little, so now I've started ignoring this screw or taking it out completely. There's two things I do to make sure the motor is secure:
  1. The mount has 6 holes (3 on either side of it). When you mount the motor to a piece of wood, place the screws in at an angle so that when the screws tighten, it cinches the mount down around the motor. The angle you want is with the tip of the screw pointing in towards the motor and the head angled back away from it. If you start with the holes in the mount closest to the motor, it seems to tighten things down nicely, then do the same with the other holes to further secure it.


  2. To make sure the motor doesn't wiggle at all, I goop a bunch of hot glue on it. This seems to give a little extra assurance that your motor won't turn while running your prop. I haven't noticed a problem with the motor heating the glue and melting it.


Pic of a motor mounted for our head popper prop, showing the angle you want to put your screws in.


Another picture of a mounted motor.




Powering the Motor

I was a bit confused when I was trying to learn how to power a wiper motor. Turns out I was just making it harder than it has to be. It is actually pretty simple, once you learn how to do it. Even if you know nothing about electronics.

Parts & tools I use:
  1. Power Adapter (aka wall wart)
  2. Crimpon connectors
  3. Wire stripper, cutter and crimper
  4. Electrical Tape


I'll add more pics the next time I do some of these steps. For the power adapter, there's two things you need to look at: Amps and Volts. Don't worry if you don't know what these things are. When you look at the power adapter look where it says what its Output is. To have enough "oomph" to power the motor, make sure that it has at least 1 amp (1000 milliamp or ma). The higher the amps, the more power it will have to run the motor. Volts is the other thing to look at on the output. The higher the voltage, the faster the motor will run. You'll likely want something between 3 and 12 volts. 3 volts is a good slow speed for a Flying Crank Ghost. The problem I've run into is a power supply that has such high amps and low volts seems to be difficult to find. I keep an eye out at thrift stores and yard sales, but usually what I end up doing is just getting one at Walmart. They have adapters where you can adjust the voltage and has high enough amps for about $12-$15. What the power supply has at its end doesn't really matter, because you'll cut it off.



The easiest way I've found to connect the power supply to the wiper motor is with crimpon connectors. You can find these at walmart as well for pretty cheap. Update: I have now started using a wiper motor from www.monsterguts.com. The nice thing about buying from them, especially if you get one of their power supplies is they also sell a connector to connect the power supply to your motor, so don't have to do any of these following steps. Monsterguts offers a 5 volt and 12 volt power supply. For most props, 12 volts makes the motor move too fast. 5 volt is more useful for most of our props. To see how fast your motor will go with the 5 volt, you can look at my Head Popper. If this is too fast for your liking, stick with an adaptor with 3 volts.


Step 1 - Stripping the Power adapter wires:
Cut the end off the power supply, and use the wiper stripper to strip the ends of the wires. You will only need about 1/2" of exposed wire.


Step 2 - Attach the connectors:
Inside each of the exposed wires, there's a bunch of little copper wires. Twist these together and then slide it into the bottom of the crimpon connector. Then with a crimper, crimp the connector down onto the wire. Do this to both of the wires from the power supply. Matching colors doesn't matter a whole lot. Once both are done, I like to wrap one of the connectors in electric tape just to make sure it doesn't accidentally touch the other when connected to the motor. If they touch, the motor may not turn on.


Step 3 - Attach wires to Motor:
The crimpon connectors fit nicely over the terminals of the wiper motor. Looking at the motor with the crank shaft pointing away from you (as in the picture), you'll want to slide the crimpon connectors over the right two terminals. Which wire goes to which of these two terminals doesn't matter. Changing them around will simply change the direction the wiper motor turns. Once these are on the terminals you can plug in the motor and test to see if it's working correctly.






Replacing the Crank Arm

  1. Aluminum Flat Bar
  2. Crescent Wrench
  3. Drill


Step 1 - Remove original crank arm:
I'll add pics soon to make this more clear. But to start, unscrew the nut on top of the motor with a crescent wrench. You should then be able to remove the arm (it might take a bit of a 'tap' with the wrench to get it off).


Step 2 - New crank arm:
Choose the length of your new crank arm based on how much movement you want. Keep in mind that the length your prop will move will be double the length of the crank arm. For example, for my head popper I wanted the head to go about 6 inches up and down, so my crank arm is roughly 3 inches. Once you have your length chosen, you can use a hack saw to cut an aluminum flat bar to the appropriate length.


Step 3 - Drill and Attach:
Next step is to drill holes in either end of your new crank arm. The hole that attaches to the crank shaft on the motor should be big enough for the shaft to fit snugly. The other end, the hole will depend on what you're doing. With the holes drilled, you can simply place the arm onto the crank shaft, and use the original nut (with its locking washer) tightened down onto the crank arm. After that you're all set!