50 SERVO 06.2015
to make the necessary modifications. Some extra time
spent on this step can make all the difference in the
performance of your completed prop.
Bandit Needs a Brain!
I decided to use two of my custom boards to control
the prop (Figure 8). The first was my Kitchen Sink
controller which provided me with the stereo audio player,
To control the jaw and allow it to be synced to the
audio, I used my version of the Scary Terry board. This
board was originally designed by Scary Terry whose website
you can find listed with the other resources. There have
been several people who have revised the original design
and this is my version.
An enclosure for the controllers was required, so I went
to my favorite. When I first started putting together my
own boards, I searched for a reasonably priced container to
house them. I often found that I was spending more on the
enclosure than I was on the completed controller. What I
needed was something that was lightweight, easy to
modify, watertight, and inexpensive. The best solution I
found was in my own kitchen. The new plastic food
containers used to store our leftovers were ideal for my
needs. My wife soon tired of searching for missing
containers and now routinely restocks my supply. It doesn’t
even come out of my build budget anymore. Perfect!
The audio is first prepared using the free software
download called Audacity. The original stereo track is split
into a right and left channel, and the right channel’s audio
is replaced with a tone track which drives the jaw circuit
If I was to build this now, I’d replace these two boards
with one of my Frankenstein boards. This board allows me
to combine all the functions necessary to control the parrot
in a single board, thus making a cleaner installation as well
as saving space. A link to my website showing the boards
I’ve made to run my haunt is included with the Resources.
Another modification I plan to do is to replace the existing
jaw servo with one with a little more torque to improve the
The code I used was very basic. It took a little bit of
adjusting to get it just right, but before long Bandit was
moving. One of the reasons I like working with the PICAXE
(besides its easy-to-learn programming language) is that the
program editor is free (see Resources) Be sure to check out
the code back in Listing 1.
With that, Bandit was ready to be put on display. You
can check him out performing on his perch at
Figure 9. Audacity screenshot
showing the split audio track.