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Step 1: The parts for the VDG
The only parts in this that you are not likely to find at your local hardware store are the wheels. I used bed frame wheels. their choice sorta dictated the size of Van De Graaff (Henceforth called VDG for short.) More about the wheels later.
These are the parts used.
1 Lightbulb socket (I pried out the bottom most contact, to give less surface area to bleed off static charges.
1 Large globe lightbulb
1 1.50"" to 2" pvc adapter (lightbulb socket fits in here nicely, and gives space to mount the brushes)
1 2" to 3" pvc adapter
1 3" to 3" PVC Coupler
1 5" threaded rod and assorted washers and nuts, I think it was 5/32"
1 6" threaded bolt, and washers, small enough for the wheel to glide on)
2 slightly curved plastic bedframe rollers. (was going to use skateboard wheels sanded down on my drillpress, but my dad had these in his shop)
1 3"x3"x1.50" PVC Tee
1 length of pvc (Ihad to use ABS which is not as good due to its carbon content, but it was all I could find in precut lengths, and didnt want to buy 9 more feet of pipe.
1 1.50" to 0.25" pvc adapter
2 sets of skateboard wheel bearings,
Some copper wire both to make a ground wire, and a spark wand wire, but also to make the brushes.
1 outlet plug (this is only connected to the ground pin
1 can of cold galvanizing spraypaint
1 can of copper metallic spraypaint
1 drill socket adapter. (to turn the bottom wheel)
1 drill, (optional speed controller)
1 sheet of latex exercise banding
1 tube of bike tire patch glue.
Teflon pipe tape,
copper foil tape
Other misc Stuff, A board to screw it down to and some long screws. and A binding post for the charge wand, some wire, a old junk drawer nob pull for the wand, some plastic tubing for the shaft of the wand.
These are the parts used.
1 Lightbulb socket (I pried out the bottom most contact, to give less surface area to bleed off static charges.
1 Large globe lightbulb
1 1.50"" to 2" pvc adapter (lightbulb socket fits in here nicely, and gives space to mount the brushes)
1 2" to 3" pvc adapter
1 3" to 3" PVC Coupler
1 5" threaded rod and assorted washers and nuts, I think it was 5/32"
1 6" threaded bolt, and washers, small enough for the wheel to glide on)
2 slightly curved plastic bedframe rollers. (was going to use skateboard wheels sanded down on my drillpress, but my dad had these in his shop)
1 3"x3"x1.50" PVC Tee
1 length of pvc (Ihad to use ABS which is not as good due to its carbon content, but it was all I could find in precut lengths, and didnt want to buy 9 more feet of pipe.
1 1.50" to 0.25" pvc adapter
2 sets of skateboard wheel bearings,
Some copper wire both to make a ground wire, and a spark wand wire, but also to make the brushes.
1 outlet plug (this is only connected to the ground pin
1 can of cold galvanizing spraypaint
1 can of copper metallic spraypaint
1 drill socket adapter. (to turn the bottom wheel)
1 drill, (optional speed controller)
1 sheet of latex exercise banding
1 tube of bike tire patch glue.
Teflon pipe tape,
copper foil tape
Other misc Stuff, A board to screw it down to and some long screws. and A binding post for the charge wand, some wire, a old junk drawer nob pull for the wand, some plastic tubing for the shaft of the wand.
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1.How do you make a discharge wand nobody online has a guide on how to make one.
2. I fired up my generator and it worked fine when it didn't go to ground, but when I finally got my ground(the plug in I wasn't getting anything, why is that?
2. I saw that on my steel bowls there are measuring numbers theres only 3 and I think they are only 1/4" big. Will they effect my charge output. If so how can I fix that (the numbers are dented on the inside and kind of pop out on the oustide if that makes sense)
2: bigger would be better, but mine using the lightbulb was not very huge and it worked. may limit your maximum spark
1. I was thinking about putting nuts on the outside of my top roller to keep it stable. Will this effect the ability to discharge when I have my roller and wire on the inside of the sphere?
2. I also need some tips on creating something my sphere can sit on as support
3.how big does the hole in the sphere have to be?
4. I got some dust on my copper roller. What is a good way to get it clean?
2: not sure, but if you make your hole in the sphere big enough to just barely go over your pipe at the top (i think you said you were not using a coupler on the top) you could go down atleast to the axle bolt. if you make it tight no mounting would be needed, if its a little loose a few wraps of electrical tape on the pipe would fatten it up.
3: i think i answered that above, alot of the professional vandegraffs just put the support tube up into the sphere.
4:Dunno, maybe a can of compressed air duster? probably wont hurt anything.
I bring the wire from a hole in the tee a bit a above the bottom roller. I then pull the wire downwards, then I bend the wire a bit upwards then make an "L" shape at the bottom of the roller where the tips of the of the brush are a bit below the bottom. Will this also work?
1. DO I HAVE IT RIGHT? 2. Did you do the same thing with the top roller?
3. Also if my wire extends more than ½” will it still work?
4. And how did get your wire to stay put? every time I move just a little bit, the brushes move!
5. I have seen people put there roller and brushes inside of the sphere. I don’t. I thought I would have my roller on the PVC, and brush wire attched to the coupling above the roller, then I have the sphere on the coupling. will it still be work?
6. On a final note would it help if I send you pictures? If so how do I go about doing that?
#3, sure, you only want it to lightly sweep the belt, but really it can be whatever length will work for you,
#4 maybe you need a little stiffer of wire? not sure without photos of your brushes what may be going on, but once i got mine in place and fanned out and trimmed flat they were really no trouble.
#5 yes the roller and the brushes inside would work a little better, less loss less bleedoff and such, but i was surprised to see how well it could work. using the socket and lightbulb (which would be impossible)
1. When I do my bottom brush I drilled a hole a bit above the roller, had it coming straight down on the inside of the pipe, holding it together with a plastic loop, when I get to where I want the brush I bend the wire up and snake it to the roller. Will this still work?
2. I got it when you said the brushes go with the direction of the roller when it’s rolling, but I am a bit confused about the tips of the brushes. Do they go along the wheel (basically flat) where the tips are a bit after the wheel, or are they before the roller, or in the middle of the roller? Or do they point upward towards the roller?
1. I have heard people wrap electrical tape around there rollers to make a barrel shape then they put a thin layer of their copper or Teflon around it. Does this actually work?
2. And was thinking about putting the screw below the roller, wrapping it up and try and get the brushes to glide on would this also work?
3. I put my dome together by bonding the lids with epoxy and wrapped 4 layers of electrical tape on the outside, the rims are still on the bowls. Will this work?
4. And I put 1 layer of electrical tape on the bottom where I cut a hole to reduce the corona charge (I think it’s called this). Do I need more layers?
2, i think as long as your pretty much on or near the roller you will be fine.
3, the lips of the bowls may cause some discharge but no i suspect you will be fine.
5, static is a bit of a different creature than most electricity we are useto. a single layer of electrical tape can stop sparks from flying in the 1-800v range, but as voltage goes up it does need to be thicker, i can only say try it out, and then maybe try it with more to see if you see any difference. it will probably be fine.
1. Where does the screw go on the tee?
2. How did you get your bottom roller to get straight and perfectly centered? When I tried to do it the belt pulled up on the roller. I also tried to get a piece of thread rod to go all the way to the other side on the bottom roller. Do you have any ideas on how to get it straight?
3. How did you get your notches so square and centered and leveled on the coupling? I am using the coupling for something else. I tried to get the notches on the PVC but it didn’t work out hints?
2, im guessing i was lucky when i pressed in the bearings, and put the fitting in everything was tight and level and my threaded rod i had already tested to see if it was straight by rolling it across a desk. im thinking if the fittings are loose at all (like the plug with the bearings in it, you might be able to use a some tape or some paper to make it fit more snugly.
3, i just handsawed them down, to a measured mark, and then broke them out. i thought they were level, but in the end i had to stick a teeny shim in the bottom of one to keep my belt centered
1. the top part of it is centered but the bottom part keep moving toward the right edge but it still is on the roller but barely, will this still work or does it need to be perfectly centered?.
2. I have also heard that the rollers material does not have to be thick. Some people said only a thin outer jacket of the copper and Teflon and have a thick layer of electrical tape underneath of that makes the bumps. Will this still work?
3. Where did you get the copper tape and what is the brand name?
4. And I noticed that copper is rubbing from the lower wheel to the belt is showing up on the belt. Will this short is out? If so how do I if it?
5. And I am still having trouble with the bottom wires. I can’t seem to get them to the right width with out them getting sucked in.
2, i don't think it needs to be thick, not sure about the rubbing off, hopefuly not enough to become conductive along much of the belt, mine didnt rub off that i ever noticed.
3, copper tape i had for a long time, i think it came from an electronics supply shop(used for rf shielding and grounding), may also be able to get it from art supply places. (its used in stainglass work)
5, not sure what you mean by sucked in, they should brush along the belt, the same direction as the belt goes, so if they are getting moved you might be going against the belt direction?
As for the dimmer box, im going to give you this image i just found off of google, just imagine that you put the 2 wires going to the light bulb to an outlet, i would also run a line up to the ground. here is a diagram for a dimmer, and followed by a diagram for an outlet, http://businesslocalarticles.com/wp-content/uploads/2012/08/wiring-diagram.jpg
and
http://www.buildmyowncabin.com/electrical/wiring-gfci-outlet.gif
I would suggest a cheap rotory dimmer switch, and there is no need for a FGCI type outlet pictured in the diagram, just cheap hardware store dimmer and outlet., mounted up in a double gang outlet box also available from the hardware store.
And for a cord, i just used a spare computer power cord, with the computer end cut off.
1.Is it ok to hold the wire going to the globe (i am using 2 salad bowls epoxed together with duct tape on bottom hole and to help hold the 2 bowls together) with duct tape on the inside, and when they say connect to the spere does that mean the entire wire is bare or just the top and is it frayed, also is does it matter how high you put the wire.
2. I am have a hard time getting the belt to stay in place any suggestions?
3. Also is the wire to bottom rollor, the wand, and the plug to ground interconnected (on the same screw)?
4. And finally is using a single piece of stranded wire ok for the top and bottom brush ok. And if not, I am having a hard time make the brushes with three any suggestions?
2, make sure your wheels are not perfect cylinders you want them to be a little bit barrel/egg shaped,(if they are not really smaller on the sides and bigger in the middle, you could clamp the wheel in a drill and sand the sides a bit. contrary to what one would think kinda egg shaped wheels help (_)======belt===(_) here my diagram is kinda sideways but if as you can see the band is going around the kinda sloped wheels, if it slips to the sides the wheel is a little smaller there which makes it want to go faster which pushes it back to the middle. this is only true if the wheels are totally parallel, I found the notches i used at the top had my top wheel just a teeny bit higher on one side, so i fixed that by putting a coffee stir-er under the bolt on the low side before tightening the nut/washer. if it keeps slipping off a side, raise up the other side by a few MM.
3, yep, they all are tied together,
4, you want as many "brushes" as you can get across the width of your belt, so either use bigger gage wire or several of them, feel free to mount it up with your brushes long, you can then fan it out and use scissors to give the brushes a flat haircut making a good brush for rubbing the belt.