I decided to do this because I didn't want to buy something that I know I can make myself, and since I'm an engineer I love building stuff. Oh, and the Destroyer Pedal is the biggest ripoff I've ever seen, $70 for something that only cost me $25 to build seems a little overrated, that guy is making a large profit, don't listen to him when he says he isn't, he just wants you to buy his product.
Well, enough with my whiny, cry baby opinion, lets get on with the show!
***UPDATE: I'm going to add how to make your own bass pad type thing for it, its way easier to do the quicker and also longer speedy sequences if the beater meets some resistence. I'll work on it tomorrow and monday and post what i come up with.
Step 1: Gather the Goods!
1 x Bass pedal - I got mine off ebay, $14.50 including shipping, here's a link to all listed pedals.
1 x Reed Switch/Relay - i got mine from Radio Shack, you don't really need a reed relay, because you will be using a magnet to trigger it, but Radio Shack only had the relay type and thats what i got. either way, they work the same in this application, fyi jameco has some cheap ones, just make sure that wherever you get it from you get a NO(normally open) type, not NC(normally closed). MAKE SURE YOU PAY ATTENTION TO THIS!!!
1 x Magnet(12 mm x 12 mm x 5mm is recommended) - I recommend getting a rare earth magnet, particularly a Neodymium magnet. I got a 'grab bag' of these once from a website for really cheap, so i have all different kinds. Sorry, but i forgot the site, or i would post a link. Here is a link to a good site though.
1 x 1/8 inch ""mono"" jack - I got mine from Radio Shack, and it came with prestripped wires so all i had to do was solder them to the leads from the reed switch.
*Optional* 1 x Soldering Iron/Solder - It makes a better, stronger connection, but isn't absolutely necessary.