There are hardly any instructables on this subject, and none with this design. It's an original idea by my dad and I. We were going for as cheap as we could go, while still making a product we wouldn't be embarrassed to use in public.

We built a full set of electronic drum pads, which I'll explain here, and also a low-cost PVC rack for the drums, which I'll post a separate "how-to" on.

Step 1: Materials

For each drum pad, you will need:

1x - 3/4 inch plywood, 8 inch diameter circle

2x - 1/4 inch foam of some sort, from mousepad or floor-mat...(more on this later), 8 inch diameter circle

1x - sheet metal, preferably of some light or medium guage, 8 inch diameter circle

1x- smaller square of sheet metal, about 2x2 inches

1x- peizo-electric element, 35mm is better, but 27mm or something will work

1x- heavy fabric, i used a material called "trigger" that's used for work uniforms, circle with at least 14 inch diameter

1x- vinyl material, 8 inch diameter circle

1x- RCA style audio jack

1x- plumbing bracket with 3/8 female threading, normally used for attaching pipe-hangers to surfaces

Step 2: Tools

pretty much just:

soldering iron + solder
hot glue gun + glue
Jigsaw
scissors
sheet-metal "snips"
heavy duty stapler and staples (1/4" or longer)
power drill
drill bits (1/4", 1/2", and screw drive bit)
short screws for attaching bracket to bottom of pad
screwdriver

Step 3: Cutting Parts

I bought a sheet of 3/4 inch plywood that perfectly fit 9 of my 8 inch circles. Draw them all out and then cut them all out at once with a jigsaw. The rough edges can just be quickly hand-sanded smooth.

We got 16 foam, 8 inch diameter circles out of the 2 foam mats. Because each pad needs 2 circles (once for under the peizo+sheet-metal layer, and one for above) this is enough for 8 drum pads. As with the wood, we just drew them all out with sharpie, then cut them out with scissors.

*For the first pad, we used 2 mouse-pads instead of the foam, but quickly realized that this would be far too expensive at 4 dollars per mouse-pad.]

For the sheet metal circles, we just rolled out the aluminum flashing, traced our circles, and used the metal snips to cut them out. If you cut them out as squares first, then trim them to circles, it makes the process a lot safer and easier. (The edges are sharp. Be Careful.)

There will be lots of left-over metal from the circles. What i did was salvage this by cutting out squares about 2x2 inches. these will be the mounts for the jacks, so they will also need a 1/4 inch hole drilled through the middle.

The vinyl can be cut into circles with a diameter of 8 inches or just under, depending on how you want your edges to look. mine are right at 8 inches, the same as almost all other parts of this design.
These circles can just be traced out, then cut with scissors.

The fabric circles will be the one element of this project that will be cut larger than 8 inches. These need to be able to wrap around the layers of wood, foam and metal, and be stapled on the underside of the plywood. A diameter of around 14 inches should give you enough to work with. This can also be traced out and carefully cut with scissors.

Step 4: Making Holes

As previously mentioned, a 1/2 inch hole must be drilled in the plywood circles. This hole should be about half way between the center and the outside of the circle. Space must just be left in the center for the mounting bracket.

For each pad, one of the two foam circles must also have a small hole poked through it. this should line up with the hole drilled in the plywood circle. The other foam circle is left as it is.

As mentioned already, a 1/4 inch hole must also be drilled in the center of the small sheet metal squares. Use caution with this, as the small pieces of metal have a tendency to spin as the drill bit goes through. I manged to cut myself on one of these spinning hazards =P

Step 5: Peizo Time

The Peizo element is really the key to this whole project. I'm certainly not an expert on the subject, but, to the best of my knowledge, the peizo produces a small charge of electricity using crystals inside. The metal side of the peizo is what takes in the impact and vibration.

What we are doing in this project, is basically increasing the footprint of this sensor, so that it covers the entire surface of the pad. This is the "reflection plate" method.

For speed, flexibility and cost, I used regular hot glue to attach the peizo element, metal side down, to the center of the circles of sheet metal. putting the glue under and then sticking the peizo into it didn't work well, so i just set it flat on the metal, and put glue all around the edges. While I had the glue ready, I also added a little over the small solder points on the peizo for support.

Step 6: Sandwich Time Part 1

Now all the layers of the pad can be sandwiched together.

1. Place the sheet-metal circle with the peizo on top on a surface.

2. Put the foam circle with the hole poked through on top of this and, push the wire leads from the peizo through the hole.

3. Push these wires through the hole in the ply-wood circle, and add that to the sandwich, on top of the foam.

4. making sure to keep your wires from coming back through the hole and getting lost, lift up the foam layer and spread some hot glue on the wood.

5. quickly line the foam pad up again with the hole and with the edged of the wood, and press it firmly back down.

6. The sheet metal does NOT get glued to anything as doing so could lower it's ability to carry vibrations evenly back to the peizo.

7. In the next step, I will show how, Now would be a good time to solder your jack onto the wire leads and test the peizo...

Step 7: Soldering the Jack

With the wires through the bottom of the plywood layer, the jack can now be attached.

1. unscrew the nut from the RCA jack, and remove the collar connector and lock-washer.
2. solder the red wire solidly to the collar connection.
3. push the small, threaded end of the jack through the 1/4 inch hole in the 2x2 inch sheet-metal square.
4. slide the lock washer back over the threaded jack, against the sheet metal.
5. Slide the collar connection with the red wire soldered to it, over the threaded back of the jack, against the lock washer.
6. screw back on the nut, holding the visible front of the jack and firmly turning the nut on the back with pliers.
7. with the whole assembly tightened down, the black wire can now be soldered to the pin connector of the jack.

You now have a whole, mounted jack assembly that can easily be pushed into the existing hole in the plywood. The sheet metal mount now lies flat against the plywood, and can simply be stapled on.

Step 8: Sandwich Time Part 2

The jack is now attached in place, the foam is glued down, and the metal peizo-circle is in place above the foam. The extra wire should lay flat between the layers.

1. Lay the other foam circle (the one without a hole) on top of the sheet metal circle.
2. The edge of the pad should now be a sandwich of:

foam
metal
foam
wood

3. To keep the sharp edge of the sheet metal from cutting the cloth covering, a strip of duct tape is wrapped all the way around the edge of the pad.
4. The pad can now be set down, face down on one of the large circles of cloth. (the jack should face up during this step.)
5. with the pad centered on the cloth, you can begin folding the edge of the cloth up and over, and stapling it to the bottom side of the pad. (If done slowly and neatly, this can look very nice.)
6. Pull the fabric tight at each point, so no slack points are left in the surface of the pad.
7. with the fabric evenly stapled around the bottom of the pad, the excess can be trimmed off with scissors, just to the inside of the staples.

Step 9: Vinyl Application

With the fabric wrapped, stapled, and trimmed, the vinyl can now be glued on.

1. Lay the vinyl circle over the bottom of the pad and the jack, lining it up with the edges.
2. feel where the jack lines up with the vinyl and mark this point.
3. I then just used a regular hole punch to make a perfect hole to line up with the jack.
4. test the fit of this hole to be sure everything lines up well and hides the rough fabric edges and staples.
5. Spread an even amount of hot glue all around the pad, going almost to the edges, and especially right around the jack.
6. lay the vinyl down flat in the glue, and smooth out the surface.
You now have a drum pad with a nicely finished base, and a jack protruding from it.

Step 10: Mounting

Depending on how you plan to mount your pads, this step may differ.

I'll give the following directions for those doing this the same way I did. This is also the way that will allow the pads to match up with the rack design I will be posting soon.

1. The brackets I used for the pads to mount were found in the plumbing department at Home Depot. They are commonly used for mounting pipe-hangers off of walls and ceilings.

2. the bracket has to countersunk holes of about 1/4 inch, and in the center A 3/8 inch receiving hole threaded like a nut.

3. Find as close to the center of the pad as you can and mark with a dot.

4. Line this dot up with the center threaded hole of the bracket (so that the pad will have proper balance)

5. Use 2 small screws no longer than 1 inch to screw the bracket to the plywood beneath the vinyl.

At this point, You should have a nice looking, responsive electronic drum pad, for far less than it would cost to buy a factory-made one, even used =P

I hope this Instructable gave someone some ideas of their own.

Thanks for reading!

Feel free to leave comments here, and any questions can be sent to Benjaminmailloux@yahoo.com
I'd be glad to answer.
I

Step 11: Kick Drum Sensor

this is the bass drum sensor I also built using mostly the same method for the basis of design. It has it's own instructable, but the link doesn't seem to be working, so I'll put some photo's here. This mounts to any standard bass drum pedal for ease of use.