wrinkles and to secure the paper (Figure 4). You want to
make sure that the paper sticks in the areas of the outline
to be cut. The paper will drag and tear if you don’t. (No big
deal if it does tear. Dab a little glue on the tip of your finger
and smooth it over the paper. The glue stick dries clear.)
After it dries, cut along the outside of the black line of
the Peek-a-Boo, but leave the bottom because it is used as
the base of the stand for the ghost. Go ahead and cut out
the arms and the stands as well (Figure 5). Set them aside
until we come to the final assembly.
At this time, gather up your IR sensor, servos, and
LEDs. Outline your servos over the small black circles
drawn in the lower left and right hand of the ghost
pattern. Make sure that the output shaft of the servo is
directly behind the black circles. Draw the outline of the
servos and cut out squares. Here’s where you can have a
The IR sensor I chose has a white dome as part of it.
At first, I was looking at this thing and thinking, “Where
am I going to put this?” Two words: belly button! (But hey,
that’s me.) You could put it in the middle of its forehead.
It’s up to you. The eyes are the same when it comes to
location. Place them where you like in the eye area.
Figure 6 shows how my Peek-a-Boo looked after I had cut
all the holes.
Glueing Pieces Together
SAFETY FIRST! You are working with HOT GLUE!
Please use caution when handling a hot glue gun and
wear appropriate eye protection. Glue comes out at
around 250 degrees and sticks to whatever it touches —
Depending on the servos you choose, the top of the
servo may fit on the back side of the ghost. If not, place it
on the front. Hot glue the arm servos in place and let it
cool. On the backside of the ghost, hot glue the IR sensor
in place. Be careful not to get any glue on the plastic lens
because it may either melt the lens or possibly block the
IR from reaching the sensor.
Hot glue the LED eyes into place. I’ve been playing
with some party ice cubes with LEDs in them that I picked
up at the dollar store. They are easy to modify for the
project and it’s kind of cool to watch the ghost cycle
through the different colors.
When you have all the pieces glued in place, the back
of your ghost should look similar to what you see in
To build the stand, bevel the bottom of the ghost at
about a 45 degree angle (Figure 8). This will leave an even
20 September 2014
out for eyes,
FIGURE 7. All components glued in place
on the back of the ghost.
A 45 degree
bevel is cut on