Using the Makey Makey (makeymakey.com) device, I made controllers that stand up to the violence of being slapped, and are cheap enough to replace if one should break.

Supplies

You will need corrugated material like cardboard box or plastic yard sign (the yard signs work better), scissors, tape, pen, exacto knife, paper clips, ruler, and wire (a run of CAT3 or CAT5 gives you lots of wire).

Step 1: Cut Up Corrugated Board

Measure the cardboard into 3" by 6" pieces and cut them out. Make sure the corrugated lines run across the narrow parts. A Makey Makey can support 6 slappers (more if you know what you're doing). Slightly round the corners with scissors so they don't poke. (You can use a dime or washer for a rounding guide).

Step 2: Fold in Half

Mark the 3" middle of each cardboard, and place a ruler on that line. Press down on the ruler while folding the cardboard over. The corrugated board will act as a spring. You want it this way. Don't mash down until it stays folded.

Step 3: Prepare the Wires

If you opted for CAT3 or CAT5 wire, you'll want 2 lengths of the wire equal to the distance you want the slapper to be from the Makey Makey. I went for about 4 feet, so I needed 8 feet of wire. Use the exacto knife to split the end long ways, so the wires stick out. You're going to be stripping the outer covering from the pairs of wires inside. In some cases, the wire comes with a nylon fiber inside that resists breaking. Pulling on this fiber parallel to the outer covering will slice it nicely. Otherwise, just pick one pair of the wires, and pull them perpendicular to the outer covering to remove the covering. For a CAT5, you'll find 4 pairs of wires. A CAT3 can have either 2 or 4 pairs of wires. If you are building 6 slappers, you'll need 6 pairs of wires. Keep the wires in pairs twisted together.

Step 4: Strip the Ends

Strip about 2 inches off of one end of each wire, and about 1 inch off the other end. Wrap the long ends around paper clips. If you don't have wire strippers, the edge of the scissors works pretty good, if you are careful. If you're not careful, you'll cut yourself.

Step 5: Tape the Paper Clips Into the Cardboard

Tape the paper clips on the inside fold of the cardboard as shown. Make sure the wires both exit the same side of the fold. You may have to tape wires out of the way. When the slapper closes, the two paper clips should make contact.

Step 6: Apply the Restraint

Cut tape about 3 times as long as it is wide. Take another smaller piece, and wrap around the center so the middle isn't sticky. Then take the two sticky pieces and tape them on either side of the slapper as shown, so it holds it slightly open, and the reinforced part of the tape is in the middle.

Step 7: Connect to Makey Makey

One wire from each slapper goes to the ground (earth) connection of the Makey Makey. The other wire goes to the various contacts - Up, Down, Left, Right, Space, and Click. It may get messy. I used bits of plasti-tak to keep the wires out of the way. You could do the same with additional tape. Plug in the Makey Makey to the computer USB, and press the slappers. Watch the lights on the Makey Makey to make sure they are working. You'll also want to put a loop of tape or plasti-tak on the underside of the slapper, so it doesn't slide around.

Step 8: Test With Hangry Hippo

Use this link to test with Hangry Hippo, a game I made in Scratch. It's currently set to work with arrows and space bar. You might need to either change the program for WASD, or reprogram the Makey Makey for arrows. Let's get Slappin'!