26 SERVO 05.2016
A printed circuit board (PCB) can be purchased from
Jeff at Simple Circuit Boards to speed up the assembly of
this mechanism (see Resources). Personally, any time I can
pick up a completed and proven PCB, I go for it. Taking the
additional time to assemble a circuit on a perf board with
jumper wires and verify its accuracy is not the best use of
my time (Figure 6).
Securing Them in
Numerous methods are
available to mount your wiper
motors. It can be as basic as
strapping it down with some metal
plumbing strap, to using
commercially available brackets
made specifically for this purpose. I
There are several commercial mounts available if you
prefer, such as those offered by Haunted Parts (see
Resources). These fit a variety of different motors and
provide a solid mounting option with minimum fuss.
If your design requires you to mount a motor to a
section of pipe, a unique plate has been created by Spider
Hill Prop Works (see Resources). This product makes quick
work of attaching a wiper motor to a 1” PVC pipe. It comes
complete with all the necessary hardware, so no additional
trips to the store are needed. These motors are heavy since
they are designed for rugged use and long life. Whatever
mounting option you choose, be certain that it will anchor
your motor in a firm and secure position.
The Beginnings of Control
There are a couple of ways to control the rotational
speed of your motor. One is to utilize a PWM (pulse-width
modulation) controller. This allows you to retain the torque
that the motor provides while being able to adjust the
speed. Although there are plenty of models to choose from,
I prefer the model available at Monster Guts as it has
proven to be impressively reliable (see Resources). These
are simply installed between the power supply and motor.
A quick twist of the knob is all it takes to set it to your
Figure 7. Post mounting hardware makes quick work
of the installation.
Figure 5. Complete door opening circuit.
Figure 4. Motor installed, ready to
open a door.
Figure 6. PCB from
Simple Circuit Boards.
Figure 8. A variety of brackets can be
adapted for this job.