Golem’s internals. Each strip is cut into four-LED sections,
then re-wired back together to create a single glowing
effect in the cracks between the rocks. It was a very long
process, but well worth the effort. The LED strips originally
ran back to a standard 44-option controller (the white
ones that come with most LED strips) which allowed me
to create a very nice pulsing lava effect.
This same method controlled the tubes on the chest,
but at a slightly different frequency. All the protruding
crystals have an amber LED under them.
Rock Golem’s upper back housed a small tube-shaped
power cell hacked from a dollar store toy (dollar stores are
where I get most of my hackable electronics). I also added
wire mesh grids to give more depth and mechanical
integration to the rocks. Under each grid were plastic red
emergency exit signs, backlighted with flickering LEDs
from electronic tea candles.
The glowing letters on the collar were created by
carving them in the foam, filling them with hot glue, then
embedding approximately 50 LEDs. This was the first
place that I appreciated the benefit of series-wired LEDs
rather than parallel ones.
The Crystal Energy Weapon
This is the centerpiece of the Golem. It is designed to
spin the outer three blades around a central “power core.”
The weapon’s power core light show consists of a column
of 14 rings of eight LEDs each, surrounded by an array of
individual LEDs illuminating the edge crystals.
The original plan was to show the weapon “charging”
via the rings pulsing sequentially in increasing frequency,
but until that animation was ready, I set it for a steady
“on” which was a bad idea — 112 low-efficiency orange
LEDs draw substantial power.
Don’t try to run four amps through a single strand of
telephone wire! It glows and melts every wire in the
bundle next to it! For that matter, avoid using telephone
wire in any circuit where there is a chance it will flex —
this stuff is brittle.
The mechanics behind the spinning outer blades
were based on the bearing system from a ceiling fan. The
effect I hoped to achieve was that as they spun faster,
they would create an electrical charge that would seem
to power the crystals. I used a 12 VDC drill mounted to a
hand-cut wooden 3:1 gear reduction system that was
attached to the ceiling fan assembly. The drill’s gearmotor
assembly was cut from the handle/trigger portion, and
motor wires were extended.
With the trigger easily hand-reachable, the pilot
could slowly pull the trigger and have the blades ramp up
to full speed (see Figure 4). This was effective and
worked quite well, but the drill gearmotor was
overloaded and pulled lots of power, rapidly killing the
This was corrected later with the help of Solarbotics
when we replaced the drill with a much higher geared
The Head of the Golem
I wasn’t sure on how to approach the head. I had built
one out of rock, but found it was not suited to the rest of
the Golem, so I decided to go the route of a machine-like
face merged into the rock. For lighting, the head had
some pulsating cracks which were tied into the body
circuits. Some LED circuits made the mouth glow orange
and the cylon-style eye glow yellow, but I wanted more
life in the face, so I added a Larsen scanner. I had a chaser
beacon that came out of the lights that are stuck on the
roofs of utility vehicles. I hacked this by tracing the circuits
and adding on longer wires so I could put all the LEDs in a
row. I also had to change out the resistors on the board to
suit the LEDs I was using (Figure 5).
Now all that was left to do was to figure out how to
get the LEDs to create a line of light across the middle of
the eye instead of the round bursts of light. For this, I took
a acrylic rod and placed all the LEDs behind it. The result
was the LED light was refracted out the other side as a flat
beam of light. When they went off in sequence, I had a
September 2014 35
FIGURE 4. The interior of the weapon arm, with the drill mounted
and made accessible to the operator.
FIGURE 5. The hacked chaser beacon.