Electronic drums are alot of fun, easy to make and can keep the cops from your house at 2 in the morning!
Step 1: Electronic Drums Triggers
First you'll need a drum set. I used a kiddie set my buddy gave to me. He bought them for his son who played them for about 2 days then they went to the garage, but just about any cheap kit will do as long as it has hardware that screws to the shell..
Step 2: Mesh Heads
The the most expensive part of this build were the mesh heads for the drums. These are the heads that alot of electronic drum sets use and manufactures sell for quiet practice but if you look on Ebay and at various musicial equipment retailers you can find deals on the sizes you need. Buy the drums first so you'll know what size heads to buy.
Step 3: Triggers
Then you'll need some piezo buzzers. These can be had really cheap too from Radio Shack or Ebay. The ones from Radio shack have a casing on them which must be carefully removed first. A small screwdriver does the trick, be careful not to bend the trigger.
Step 4: Mounting
Then you'll need to mount the piezo inside the drum. Simple hardware store angle brackets worked like a charm. Just screw on with some of the hardware on the drum. Then cut some thin aluminum strips, again from same hardware store bought in like a 4 foot length strip, trim to fit inside your drum, drill a hole in each end to bolt to the angle brackets. Be sure you use lock nuts everywhere so they wont come apart.
Step 5: Attaching the Trigger
Then you might have to make some kind of height adjustment depending how far away from the top of the drum your cross bar is. A short strip of aluminum and some long bolts and lock nuts worked. Drill a couple holes and bolt it together. You want the triggers no further away then 2 inches from the top of the drum. Glue the trigger to the crossbar or to the riser then glue some foam to the trigger. Make sure the foam is taller then the top of the drum. Then you'll need some wire and a 1/4 mono jack for each drum. Get the thick panel jacks cause they will have to go thru the shell at the vent hole, which might need to be opened up a bit to fit. Parts Express fit the bill here.
Step 6: Cymbal Triggers
Now for the cymbal triggers I just used some PVC. A "'T" section, a 2 foot pipe section and an end cap. You'll solder some wire to the trigger thats longer then the whole unit, then fish it thru the "T". Hot glue the trigger in the T section, then drill a hole in the end cap. Run the wire thru the pipe, thru the nut and washer and thru hole in the cap then solder the wire to the jack then mount the jack in the end cap. Tighten the nut and washer on the jack. Glue the 3 pieces together and glue some dense foam rubber I fond at a hobby store on the T section that will be used as the striking surface. Then just get a brain to connect them to to make some sound. Grab your head phones and cables and your good to go. This is my first Instructable, hope it's understandable! Peace.