Build the Foot Switches

Cut the Materials

Each switch is a stack (from bottom to top) of wood, metal, metal, plastic, graphic, plastic. For the wood I used some 3/8" MDF I had lying about. For the plastic I used 1/8" acrylic. I had wanted to use polycarbonate for strength and scratch resistance, but it was twice as expensive. I went cheap with acrylic, and it has turned out to be ok. The wood and plastic for the switches is nominally 11"x11", but it needs to be marginally smaller to allow a good (but not too loose) fit within the metal squares. Here we see the acrylic sheets (with the blue protective cover still in place) sitting within the squares. There are two plastic pieces per switch. This picture isn't very informative- but the blue on wood looks cool, in a sort of retro 70s way.

Laminate Metal, Plastic and Wood

Each switch has two sheet metal pieces held apart by 1/8" weather stripping. Having cut the sheet metal plates, wires need to be soldered to the edge. You will need clean surfaces, flux, and a high power soldering iron to do a good job of this. After the soldering is complete, four of the metal plates are glued to the wooden switch bases with contact adhesive.

The other four metal plates are similarly glued to four of the acrylic pieces. Once again, the pieces should be clamped while the glue sets.

What's a Project Without Duct Tape?

The edge of the sheet metal may be a bit crinkly (or at least it is the way I cut it), and it may have the tendency to curl up. To prevent this we tape around the edges of the metal and wood with duct tape. This holds down the metal and insulates the edges. Only the smooth central area is used to make electrical contact.

The plastic pieces get the same duct tape treatment. This is a view of the plastic piece from the bottom side.

Here's the view of the same plastic piece from what will be the uppermost side. The blue protective cover has been removed from the acrylic at this point, so you can see through the acrylic to the contact adhesive holding the metal plate on.

Assemble the Weather Stripping

The weather stripping is applied to the wooden base of the switch. I used 1/8" high density weather stripping. It doesn't really compress much in usage, because most of the movent is caused by the plastic flexing downwards. It should be reasonably compliant and resilient so it can maintain a small separation between the plates. If you look carefully you can see a gap at the edge. This is to allow air to escape when the switch is pressed.

Assemble and Test

Here's the switch stackup bolted together for testing. The corners have been drilled to lineup with the holes in the metal braces. The arrow graphic is sandwiched between the two uppermost pieces of plastic. I printed out the graphic on a color laser printer that could handle the 11"x11" size. It's not perfect. You could do a better job by printing it out on photographic quality paper- but I would've had to go to Kinko's for that.

And here we are ready for testing. Foot off- resistance is infinite. No shorts. very good.

... Foot on. Resistance is <= 1 ohm. Foot pressure is moderate. Looks like the switch is good! Now- build three more like that one, and when your done hook them up to a hacked PS2 controller.