5 or 6 feet of 1/2" PVC pipe (PVC pipe is usually white, as opposed to ABS pipe which is usually black. The initials will be somewhere on the pipe, make sure you use PVC, not ABS or CPVC)
5" to 7" section of 4"PVC pipe for drum/cylinder.
Two caps for 4" pipe, a hole drilled in the exact center of each to fit a length of 1/2" PVC. The caps I have used are called "test" caps. They fit flush with the edge of the pipe and are smaller and less expensive than the regular schedule 40 caps used to seal off 4" pipe.
four 1/2" PVC elbow joints
two inches of 3/4" PVC tubing
one 1/2" PVC cap
PVC cement
6" to 8" x 1/2" copper tubing with cap on one end for prime conductor/ collector
6" to 8 " x 1/2" strip of metal bug screen for charge pick up (or piece of metal flashing, one edge cut with pinking shears). This is attached to the prime conductor and brushes against the PVC drum. The fine points of the screen are able to "collect" or "pick up" the charge created on the PVC drum as it rotates.
1/2" (outside diameter) x 12" to 14" metal rod or metal pipe for "axle." This should fit closely inside a 1/2" PVC pipe. The PVC pipe will rotate around this stationary rod. Avoid the temptation to use wood, it's a little too flexible.
board for base
2 feet of bead chain or wire
rabbit fur (other materials work as well- experiment to find what works best)
Leyden jar- check this link for instructions on how to make one of these. All you will need is a film canister or baby food jar, some aluminum foil, wire, a small bolt, and a couple of nuts.
Notes: This list won't do much for you unless you know what to do with it. Before you do anything else I would suggest making a Leyden jar, then charging it with a piece of PVC and rabbit fur or wool. I would also suggest a thorough look through SCIENCE HOBBYIST's"Static" Electricity Page and a look at the books in the bibliography on the previous page. That will give you some bearings on which to proceed. It should also give you an idea of how to adapt a design that suits your needs or budget.
Make sure that the fur rubbing pad is grounded. I have simply attached a piece of metal bead chain to the fur and let it touch the wooden base of my generator. Also, don't use more fur than you need. Too much seems to cause problems. A strip 2" wide by 6" long should be enough. I have had a variety of results when adjusting this pad. On some of my generators it makes a big difference if the skin side of the fur is making contact with the PVC cylinder. I have tried a chamois pad but haven't had very convincing results. Make sure you try lots of different things to get the most out of your machine. Small adjustments can sometimes make big differences.
An exception to grounding the pad is to run the bead chain to another Leyden jar (you may notice the photo on the main page shows this). That way you will electrify two jars at once, with opposite charges. Physics in action.
To anchor the large PVC cylinder to a length of 1/2" PVC tubing you will need some 3/4" PVC tubing. One way to do it is this: Cut two 1" sections of 3/4" tubing. Next make a cut through the side of each 1" section. What you are left with is two short pieces of 3/4" inch PVC, each with a slit through the side. These will open just enough to slide snugly over the 1/2" pipe. One of these glues to the top cap and one glues to the bottom cap. This joint receives the most torque, so assemble it carefully.
If you can afford it, buy some metal foil tape (not duct tape!). It's used to repair metal duct work and for certain insulation applications. The tape section of a good hardware store or even a department store will have it. It can help speed experiments along and make construction easier. Works great for Leyden jars.
A recent design change for my machines has been to replace the charge collectors. The old ones were pieces of metal window screen, taped on to the prime conductor so they brushed against the PVC cylinder as it turned. The idea is that fine points will "collect" the charge that is created on the surface of the PVC. I got some aluminum flashing (a piece of a soda can works as well), and cut one edge with pinking shears (the kind that make zigzagged edge). I fastened this to the prime conductor by drilling a hole and screwing it on. The PVC cylinder doesn't actually have to touch the metal points, but it does have to come very close.
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Examples of Charge Collectors. From the top, clockwise: Metal bug sreen with foil tape, aluminum flashing cut with pinking shears, and metal screen with electrical tape. |
The lower the humidity, the better any frictional generator will work. Another way to look at it is the dryer the generator, the better it will work (get out your blow dryer).
A drawing that may help make more sense of what you are looking at
Tips on using materials for electrostatic experimentation
Some more tips on dealing with high voltage, low current electricity