Wimshurst Generator #1

    During my Sophomore year of high school I built my first Wimshurst Machine. It was quite a struggle, and I learned a great deal along the way. It went through a few incarnations, both with and without sectors, until being fitted with a pair of plexiglass sectorless discs and a permanent motor drive. The first version of the generator was built simply to prove that I could build it - that I knew enough, and what I didn't I could figure out along the way. I spent as little money on it as possible, basically using only what I had available to me in my high school's little machine shop, what I had laying around, and what i could get from friends/relatives. 

    Later on I partially finished a much improved device, using a pair of directly motor driven 12" plexiglass discs. Unfortunately one of the disc bosses was improperly machined and makes its disc slightly off balance. This induces a dangerous amount of vibration into the discs that can move at a few thousand rpm, so I never bothered to finish the thing. Eventually I want to machine new bosses and replace the discs with ones cut from PP, PE, PS, or G-10 fiberglass laminate. Then I'll add a proper HV collection scheme following the very good advice in R.A. Ford's book "Homemade Lightning."

 This Describes the First Incarnation(written when I was 17)

Using a pair of 10" bakelite 78rpm records, I began to fashion this contraption in my mind. I abandoned the want to make it motor-driven rather swiftly, settling on a more classic hand-cranked approach. The only part I was really worried about was how I was going to make the discharge terminals movable, for obvious reasons. This I solved in a simplistic manner, by running my two HV buss rods through a section of 1/2" thick plexiglass, and drilling a second set of holes down into the plastic, so a rod set into the open holes would rest on top of the HV carrier, making contact. With a little bending of the rods supporting the terminals themselves, I set them up so that they might be easily adjusted by swiveling in thier bases.

The whole thing was mounted on a piece of particle board, With two upright supports being the only connection to the wood. These were held in place with a set of metal braces I made. Originally I tried to use a section of wooden dowel to support the two discs, which both rotated freely on the same fixed axel, as I afraid that if I used steel it would present a problem. But i had to dispense with the wood; it flexed a little too much, and the discs touched eachother at their top edge, while remaining over 1/4" apart at the bottom edges. Steel rod was neccesarily substituted, and doesn't seem to present much of a problem to the operation.

Each disc is cemented onto a lexan boss turned on the lathe, with three layers of thin rubber gasket sandwiched in between the discs and the bosses. The bosses were center-bored to rotate feely on a 1/4" shaft. When the fixed steel axel was set accross the two upright supports, the discs sat level enough that they wouldn't progress at all when spun. I happily dispensed with the springs I had been trying to use to compress the discs towards one another, along with the collection of washers I had added. All of that squeezing and slipping added an unwanted amount of resistance.

Each disc boss had a pulley-like groove set into its narrowest part, for the drive belt to rest in. The bosses were driven by belt from a set of larger pulleys fixed to a shaft running through the uprights near thier base. For the belts, I used a pair of extra-long heavy-duty rubber bands, which I kind of regret as they aren't very sturdy, and while I haven't had one break on me, they do produce copious amounts of fine red powdered rubber. It sticks to everything and I KNOW that it has to be hurting the generator output. So that the discs spin in opposite directions, one belt makes a figure-eight while the other does not. A simple crank is attached to the end of the pulley drive shaft, though I made it attach by threading part of it on, so it can be removed easily. This allows for the possibility of rigging a motor drive for it, as I did once... ...thing squeaked like a banshee.