A Pair of Homemade Dance Pads

Copyright September 2, 2005, published at computertips.toups.info All rights reserved.

Modified September 24, 2005. (Added grade for "Fun Rating".)

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The Project

Below is a picture of the nearly completed dance pads. If I can manage to tear them away from the family for a few days, the intent is to stain and polyurethane the exposed portions of the outer frame. The first thing you will notice is that these pads are not clones of the various metal pads that have been built.

Design Goals

My design goals were:

Pretty quickly, I settled on a few aspects of the design. First, the tiles would be made of wood and would be covered with vinyl floor tiles. This route has several potential advantages over metal or Plexiglas/polycarbonate dance pads. The perceived advantages are that this design is

The tile and switch design came next. From here on in the discussion, the word tile will be used to refer to the 11 inch square by 3/4 inch thick plywood square ultimately with the vinyl floor tile attached. After viewing lots of options for making the switch contacts, I decided to try a design of my own invention. The details will be discussed later.

Assembly

The first step is to build the base and outer rim. A key thing to remember is to leave some clearance so the individual tiles can move. My recommendation is to cut the 11 inch squares out first. (If one desires, they can be made a shade less than 11 inches to allow for the required gap.) Both the base and tiles are made from nominal 3/4 inch span rated plywood. The floor tiles are 12 inches square and will have to be trimmed. It is easiest to work from the top surface and use the plywood square tile as a guide for a razor knife to score the top surface. Then the tile may be bent and broken off. If you make them slightly larger than the plywood squares, an old fashioned hand plane can be used to neatly trim the tile to size after it is attached.

Lay the plywood tiles out on the base with a couple of playing cards between them to give the desired clearance. Then layout the side, top and bottom rails. On my version the side rails and inner front rail sit on top of the base while the very front and back rails are butted to the plywood. The only reason it was done this way was that it allowed me to better make use of the size of plywood that I already had available. An overly liberal use of woodscrews was used to assemble the base and frame. The next two photos show the side and front view of the nearly completed dance pad. Note when cutting the rails to height, remember to account for the height of the switch assemblies.

Notice in the preceding photo the closed box at the front center, this is the box that contains the controller circuit. The inner front rail is notched to allow the wires to enter. The cover is 1/4 inch plywood and there are rails under each side at the screw location. These rails are also notched to allow the wires from the two small switches to enter. Also note that a piece of anti-fatigue foam floor matting (found in 36 inch wide rolls cut to order at a home supply store) is being used underneath to protect the floor, prevent slippage, and reduce noise.

Next are the details of the switch assembly. The next two images show the dance pad with the tiles removed. The brass strips that you see are the switch assembly that will be detailed shortly. The gray strips are the pieces of poly foam open cell weather-stripping (1/2 inch thick x 3/4 inch wide, two 17 foot packages were used for this project) that are used to support the tiles. The weather-stripping is also used to assemble the switches. The key feature of the design is that no switch wires or contact plates are attached to the tiles. Initially, the plan was to add a single (or maybe four) countersunk screw(s) from the backside prevent the tiles from being removed. The countersink would be deep enough to allow the tile to travel up and down without the screw hitting the floor underneath. However, after extensive playing, this appears to be unnecessary.

Having the tiles easily removable has several advantages. It is a simple matter to remove the tiles and clean the base of the normal dirt and dust that accumulates. It is also a simple matter to add additional foam as needed to tweak the performance. After extensive use, some of the foam flattens out so that its restoring force is weakened and the tile is presses the switch under its own weight. Adding some additional weather-stripping returns the tile to normal operation. Also, to move the unit, it is lighter to remove the tiles and transport the base and tiles separately.

Main Contact Assembly

The items used to assemble the switches are:

Brass was chosen for its ease of soldering and good electrical properties. The rubber pads and foam mounting tape were chosen in the hope of limiting the overall noise of the dance pad. The first step in building the main contacts is to place the rubber pads (1 inch squares cut from the 1 inch x 4 inch rubber pads) along with approximately 1 1/2 inch strips of the foam weather striping in each corner of each tile. For symmetry and to possibly avoid interference between the switches, the layout rotates from corner to corner.

Next the wire is soldered to the bottom of the 1 1/4 inch long strip of brass. The brass is longer than 1 inch to allow the wire to be soldered to the bottom and not interfere with the attachment to the rubber pad. It is attached using the foam tape.

Below is a cluster of a set of four completed switches. Each switch is for a different tile. The top contact also has its wire soldered to the underside of the strip and is attached to the foam weather-stripping with the normal double sided tape.

The contacts for the two small upper switches (start and back) are a bit different. In this case the bottom contacts are a bit different. A strip of foam is at the extreme edge. Next two bottom contacts (similar to the main contacts) are located next to the foam at the front and back of the switch. Another foam strip is placed between the bottom contacts. A single top contact is made with the wire soldered to the center. This contact rests on the foam "T" and is slightly offset from the bottom contacts to allow the foam to support it. This can be seen in the next photo.

Wiring and Controller

For each tile, two wires are brought to the controller area. All the lower contacts for a single tile are connected to one wire; all the upper contacts for a single tile are connected to the other wire. A single "ground" or "return" wire was not used for all tiles since the controller used has a multiplexed set of inputs.

Since the main use of this pad is with a computer and StepMania, the main requirement was that the controller be cheap. A game controller would suffice. (For those with a console game, an appropriate controller will be needed.) The cheapest controller that I could find readily available was a Saitek model.

It turns out that this was a very good choice. With the exception of one "return" wire, all soldered connections could be made in an existing hole with a solder pad.

The controller boards are photographed from the wrong side. There are 8 game pad buttons that can be used. There are also two throttle buttons, however, I recommend avoiding these. There are also 4 joystick contacts. The issue with these is that only two adjacent ones can be pressed at a time to get a valid input. "Up" and "Right" or "Up" and "Left" is valid but "Up" and "Down" will not generate a code. Similarly "Left" and "Right" will not generate a code. So by wiring "Up" and "Right" to the small tiles ("Start" and "Back"), one can use the remaining "Down" and "Left" as part of the dance tiles. The actual scheme used is up to the builder.

As mentioned earlier, this controller uses multiplexed inputs. So there is a separate return wire for different sets of switches. By tracing the wires, one can determine which returns service which switches and wire appropriately.

Conclusions

I have to consider this project a success. If we are to grade this based on the original design criteria, the grades would be:

Of course, the only grade that counts is whether or not it is fun to use:

Related Links

Simulators

www.stepmania.com StepMania dance simulator

icculus.org/pyddr PyDance is another dance simulator.

Dance pad Information

www.ddrfreak.com has lots of information on DDR and DDR-like games including a long discussion forum thread on homebuilt dance pads and tons of links to a variety of designs.

The nominal dimensions of a pair of dance pads can be found here which is sub page of a site detailing a 4 switch metal homemade dance pad found at www.geocities.com/ddrhomepad

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