Instructables

Mini Van De Graaf... M & M style!

MiniVDG.jpg
vdg.jpg
Bottom.JPG
brush.JPG
glassroller.JPG
I'd been thinking about making a VDG generator ever since I read this Instructable and this one too , and I'd read up on how they work: http://www.rmcybernetics.com/science/high_voltage/contact_elec.htm, but I was at a loss as to what to stick on top of the thing... until I came across this ~3" metal M&M box, just crying out to be charged up!

(It's only entered in the tool contest because of the Makita-as-motor, which is at best a stretch, I'm fully aware)
 
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Step 1: Materials

Picture of Materials
In keeping with the purest standards of junk craft, I refused to purchase anything for this project. But over time I was able to extract the following from my various hoards of trash:

Here's a great reference:
http://www.rmcybernetics.com/science/high_voltage/contact_elec.htm
(The diagram I've posted is from that page)

Sphere:
- Metal M & M
Brushes:
- Copper wire, solid
- copper wire, stranded
Belt:
- Big black rubber band: 1/2" wide, ~6" extended
Housing:
- 1" diameter PVC pipe (cut to a bit over 7")
- Old PC power cable (for ground)
Roller #1:
- 1/4" dia. bolt; 2 1-4" long (toilet tank mounting hardware, if I recall correctly), & nut
- plastic "beads" from a jump rope (my daughter's jump rope had half a dozen of these left over after I shortened her rope)
Roller #2:
- Wire hanger (welding rod, etc would work)
- glass beads
- Gorilla Glue
Drive:
- Cordless Drill (I tried using some random motors, but none of them had enough torque to spin my low-tech roller!)

NOTE: none of these measurements is exact, nor do they need to be; for instance I cut the PVC pipe to fit the rubber band I had.

Tools:
- hacksaw
- drill
- wire strippers, cutters
- soldering iron

junisponds6 years ago
hey this is cool. i'm going to post it on our Tool Blog, www.toologics.com on Friday March 7, 2008.
mcraghead (author)  junisponds6 years ago
Hey Jude

Thanks for the mention!

"...using my favorite drill, the Makita BDF452HW cordless LiIon drill/driver..."
I agree, that drill is truly well built; half the weight and twice the power of the big ol blue Makita I used to use, plus it charges up faster than any rechargeable item I've ever owned. The only problem with this setup is the automatic "spotlight" on the drill makes it harder to see the tiny bolt of lightning you're trying to create with the VDG!

Cheers

Mike
try putting a small bit of electrical tape or sticky tack over the light.

cheers
berq mcraghead6 years ago
Yeah! More shout-outs for the Makita 18V Li-ion! Some of the best money you can spend. I've used mine for everything from unscrewing tiny electronic devices to drilling a 5/8" hole through a steel plate. Always a satisfying experience.
kydlt3 years ago
Hi Mike,
A x-section of an old intertube makes a great belt.. a motorcycle gives about a 6 " belt, a semi truck tire will get you 20" +.
great instructable !
dennis lee
dale2834 years ago
Nice work! But your photography needs some help.  Most cameras have have a small flower icon.  When activated, detail will come in to focus. 
Kirbsome!5 years ago
I'm about to build a VDG myself. Would I get a bigger spark with a longer PVC pipe and belt?
mcraghead (author)  Kirbsome!5 years ago
My guess is yes, but I think the materials themselves are more important than their dimensions. I built another one using a food processor motor that was about 3 feet tall, and that definitely sparked more than my drill-powered one!
how much did this cost you.
mcraghead (author)  coolpizzadude5 years ago
The drill was the spoils of victory from the 2007 Halloween contest, and the rest was already in my junk drawers, so the only cost was labor...
n0ukf6 years ago
Did it ever occur to you that you got jolts from the drill because you're driving the high voltage end instead of the grounded end of the loop?
mcraghead (author)  n0ukf6 years ago
Not much occurs to me... but that finally did. But rather than drastically redesign, I just properly insulated the top roller from the drill chuck, and got much better results. I also just made a full-sized VDG (driven by a motor from a Kitchenaid food processor) that works like charm; the only jolts are from the intentionally jolty parts...
junisponds6 years ago
Thanks! I posted your comment as well:
The link to the article in case anyone wants to check it out is:www.Toologics.comwww.Toologics.com
Kiteman6 years ago
For getting decent sparks, google for tribolectric series, and if people are bothered about using the mains as an earth, an equally-good earth connection can be made via the mains water-supply.
mcraghead (author)  Kiteman6 years ago
I'm still trying to figure out how to make a roller out of rabbit fur...
(Thinks)

Don't - replace the lower roller with a pad of fur, but have the belt looser, so that it just brushes against the fur.

(Maybe?)
Charger_066 years ago
I've made one out of legos and am making an instructable of it.Does any one know how to test it?
tape strips of tissue paper to the top, if the tissue paper flys up, you got yourself some power!!!
mcraghead (author)  Charger_066 years ago
You should be able to get a spark to jump to your finger, or at least get a strand of hair to either repel or attract...