Concept: (void*) is an abstract furry costume (yeah, (void*) is a C programmer joke. I'm a nerd, sue me). 100% black spandex from head to toe, it's based on a black spandex zentai suit with a modified head.

I built a clay model of the head structure based on a lifecast of my own head:

Layer 1 of a carbon composite 'skull' helmet for (void *):

It turns out that carbon fiber fabric is a little harder to work with than fiberglass, but the results are excellent; the weave is loose enough that you can form the fabric to almost any 3D curvature, as long as you're patient with pushing the sags and bubbles out until the polyester resin begins to harden.

Also, when I'm doing fiberglass, I coat both sides of the mesh with resin and squeegee it out. Since the carbon fabric is so much more delicate, I just tap one side (the backside) of the mesh into the resin and then carefully lift it out. By the time it gets pressed onto the model, the resin has oozed all the way through to wet the whole mesh, and there's a lot less drip that way.

I added a bit more kicker than usual to the resin so that it would set up faster. The down side to the loose carbon weave is that it unravels very easily, especially with the force of the polyester resin dripping out of it; that motion alone can unravel the fibers, causing frayed edges and a bit of a mess during application.

Here I'm applying the finish coat to the structure to make it smooth and give it that sexy black sheen (no, the skull won't actually be visible in the final product. This is just for style points). The skull has been demolded and portions cut away for weight, vision, and air transmission:

Okay. The skull structure, the hinge and latch, and the internal padding are done. I still need to add the electronics and "skin" it with spandex, but here's the basic shape of the character:

Currently the costume's complete mass is under 800 grams.

The LED light sequencer circuit:

Operation: A 4 bit counter (CD4516BF) counts in the current direction (pin 10) one click with each clock coming in on pin 15. The clock is generated by 3 of the inverter gates with RC components that let me tune the speed from about 1Hz to basically infinitely fast. The counter feeds the 4:16 decoder, lighting up whichever of the 16 LEDs the 4 bits currently encode. When one of the LEDs on the end light up (pins 11 or 15), the direction switches in the RS flip-flop made from the 1st and 3rd inverters, which sets the direction to "up" when LED 0 lights, and to "down" when LED 15 lights. Since it's not good to try driving 20mA of LED directly off a logic line, each line goes to a small transistor-based switch on the driver board in the other ear. That board also has a Toggle flip-flop made from a D flipflop (feed !Q back to D), triggered by the CLK line fed from the last LED. The effect is that each time a right-left wash is completed, the Toggle flipflop changes state and powers a different NPN transistor, one on Q and one on !Q. This allows the wash to alternate colors, once per sequence. The eye slot has room for almost exactly 32 LEDs. The circuit is based on this original design.

The eye prototype:

The PCB laid out:

Here the costume fabric has been completed, except for the shoe modifications:

Here's both boards. The left is the sequencer/logic board. The right one is an array of drivers for the LEDs, and a little Toggle-flipflop circuit that bounces the pattern between blue and red, one pass each.

The visor element with all the LEDs connected to it:

The first wear test with the visor in place.

Closeup of they eye circuitry. The logic board is in its right ear and the the driver array and color-changing logic board is in its left ear.

Video of the eyes in action:

Here is a behind-the-scenes look at setting up one of the shots for the Whorythmics video (The Dalek-buddy shot). We used a chromakey backdrop for the live sequences.

Some production notes:

Here's the video!

Other costumes I've built...
Copyright © 2007 by Kevin Kelm