How Do You Shut This Thing Off?
We sometimes are faced with the opposite problem
and need to control when a motion is paused or stopped.
In this situation, limit switches can come to the rescue.
Adding a limit switch or two to your design may be just
what the doctor ordered when trying to get a mechanism
to start and stop in exactly the right spot. The first time I
used this approach was for an opening coffin which
followed the design put together by friend and fellow
haunter, Gary Adams ( http://tinyurl.com/oln7kjn). It
allows a wiper motor to rotate 180 degrees, pause, and
then continue rotating another 180 degrees to its starting
point to wait to be triggered again. You can see the motor
and limit switches in action at
A Small Price to Pay
Trigger components are often overlooked when
preparing the design budget, but play a key role in how well
a character performs. With a wide range in cost, it does not
have to be an expensive component. However, this is not a
place to skimp. Spend a little extra if needed and get the
correct component to achieve your desired effect.
It’s All in the Details
Finding just the right solution for a problem can be
challenging. Do not be afraid to try another method if your
current attempt is not working correctly.
You can improve the performance of your sensors with
a bit of code manipulation when using your sensor in
conjunction with a microprocessor. Consider the example
codes presented here as simply guides. Take the code and
adapt it to optimize the performance of your particular
design. Bend it to your will!
We all have a tendency to use techniques that we are
familiar and comfortable with. Use this as an opportunity to
build your knowledge base. When up against a deadline,
that’s not the time to be investigating new techniques.
Spend some off time experimenting with previously untried
methods that can then be incorporated into future designs.
Exploring new techniques can help keep your interest
high and your passion alive. If you do the same thing over
and over again for long enough, you will eventually lose
interest and find something more interesting to do. Do not
let the spirit die!
It’s Time to Put This Topic
As you can see, there are plenty of ways to tackle this
issue and I have touched on just a few. I hope you take
some of the ideas presented here and give them a try in
one of your future projects. The ability to precisely
determine when a prop will activate is a valuable tool.
As you have seen, sensors can perform the necessary
role of tripping your prop, but they can also do so much
more. Being able to utilize numerous techniques will elevate
your designs a step above the ordinary and make your
creations stand out. There are many choices and being
comfortable using a variety of different technologies will
make you a better builder.
Do you have an idea on how to better utilize these
sensors? What is your favorite way to trigger your designs?
Please post them in the DIY Animatronics forum at
http://tinyurl.com/qjeehjs so that everyone can benefit.
28 SERVO 12.2015
Figure 9. Figure 10.