(original version 10-29-2013)

Clay Cowgill, October 29th, 2013

I had the idea for the eyeball buttons early on, but I was puzzled about what to do for the joystick. While looking at my box of Halloween 'stuff' I spotted a cheap styrofoam femur.  I couldn't recall ever seeing one of *those* on a joystick, so I decided to go with it.

The styrofoam bone was not quite the right size and it was rather cheap looking, so I wanted something better.  As luck would have it, I had a shiny new Form1 3D printer on my desk that I'd been itching to use for something other than printing little Tron recognizers and miniature Atari 2600's.  I found a 3D dataset online of a scan of an actual human femur-- I was able to import that to MeshLab and hollow out the model, then scale it down to the size I needed and print it on the Form1.

Here is the hollow piece after removing the support structure. 

I proceeded to cut the plastic knob off the top of a Happ Super Joystick to go with it-- you can see that mounted up in the center of this photo along with the buttons.  The buttons are acrylic 'doll' eyes that I did some extra painting to and sealed with a nice gloss sealer.  The buttons are just standard Happ microswitch pushbuttons.  It turns out that there's quite a bit of extra plastic on those, so I was able to make a little fixture and turn the tops of the buttons down on a lathe so that they match the internal curvature of the eyes.  Once that was done there were glued in place with a strong urethane glue.

The hollow 3D SLA is way too fragile to survive arcade use, so I made another silicone mold of it (while attached to the joystick shaft).  The joystick shaft was then co-molded with bone colored urethane plastic resulting in the final product.  (You can also see the control panel overlay with the acrylic backer board being cast in the background of this shot.)

Finally, here's a close-up of the button in 'final form' and mounted in the control panel.