Static Cling / High Voltage / Forums

Forums

4hv.org :: Forums :: High Voltage

« Previous topic | Next topic »

Static Cling

Move Thread

LAN_403

Zonalklism

Tue Dec 19 2006, 04:13AM

Registered Member #213 Joined: Sun Feb 19 2006, 05:48PM
Location: Blythewood, SC
Posts: 39

I just built my first Van de Graff generator, and after having it run for a while, I started to want bigger sparks... So I got to messin' with it and I kept moving the wire that comes off my ion spray source closer to it to increase the amount of charge that would build at the top. This of course worked, but only to a certain point. Once it gets about an inch away from the belt, it will run for a few seconds, and then one side of the belt will jump to the pvc pipe that encases it. I guessed this to be static cling. Is there anything I can do to fix this, or will I just have to keep the wire a certain distace from it?

747391

cbfull

Tue Dec 19 2006, 01:11PM

Registered Member #187 Joined: Thu Feb 16 2006, 02:54PM
Location: Central Ohio
Posts: 140

I am going to make a wild guess that your belt is made of some kind of very elastic material, is this correct? That is the problem that most VDG builders encounter until they can find a belt material that has fabric in it. It is definitely a good sign that your belt is carrying a decend charge, but the belt is the limiting factor here. It seems that you should be able to get your spray points much, much closer than one inch.

It just so happens that I am in the process of making a new belt for my VDG, out of neoprene coated nylon, 0.022" thickness. I bought it from McMaster Carr, and I had to buy 10 feet of a sheet that is 60" wide, so I don't think I am going to run out anytime soon. I chose this material because thin belts can be run very fast, but they also tend to not last as long (I'll just make another one).

Zonalklism

Tue Dec 19 2006, 05:10PM

Registered Member #213 Joined: Sun Feb 19 2006, 05:48PM
Location: Blythewood, SC
Posts: 39

Actually, no, my belt is made out of red ribbon material that was laying around in our garage. However, could it be that my belt just isn't tight enough?

cbfull

Tue Dec 19 2006, 07:28PM

Registered Member #187 Joined: Thu Feb 16 2006, 02:54PM
Location: Central Ohio
Posts: 140

That would be the first thing I would try. Are your rollers able to move to tighten the belt? You can probably just slide some shims somewhere depending on how they are mounted.

I am curious, what are your rollers are made of?

Marko

Tue Dec 19 2006, 07:32PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

In case this fails, you can always use a wider tube. Something like those 110mm plumbing will do well I think

Zonalklism

Tue Dec 19 2006, 08:32PM

Registered Member #213 Joined: Sun Feb 19 2006, 05:48PM
Location: Blythewood, SC
Posts: 39

My rollers are only able to move about a millimeter or two, and this is just cuz the hole is a bit too big. The way they are made is I took a wood dowel and drilled a hole for it in the pvc. I then slid (past tense of slide?) a piece of pvc over the dowel so as to reduce friction. The pvc is wrapped in a couple layers of duct tape to increase its size.

teravolt

Mon Dec 25 2006, 01:14AM

Registered Member #195 Joined: Fri Feb 17 2006, 08:27PM
Location: Berkeley, ca.
Posts: 1111

the mateials that you use are critical. noeprean is a good choise for a belt. I found that a lot of rubber materials such as inertube has carbon in it. a cloth belt made of a 100% synthetic material like nylon work. the belt must be a compleat insulator. Science First has rubber belts maby you can slpice 2 togeter.
I made the lower pulley out of soft polyethaline and the top one out of aluminuim. when you make them crown the edges of the pullies so the belt won't slip off

cbfull

Sun Dec 31 2006, 09:32AM

Registered Member #187 Joined: Thu Feb 16 2006, 02:54PM
Location: Central Ohio
Posts: 140

Neoprene has been getting the highest scores from the home-doers I know of. Nylon would make a great belt except the belt needs to keep the charge from going right through the belt and spraying the pulleys, so there just happens to be a very, very thin neoprene coated nylon that you can buy from McMaster.com.

Initially I was concerned that it was loaded with carbon black, but another VDGer tried it and got very promising results.

I just purchased a nice roll of it so I can replace my older, 1/32" thich neoprene/nylon which is quite a fearful thing if you try to run it very fast. I only needed that to happen once to learn the lesson. It exploded apart and took out both brush assemblies, breaking them into many pieces. Luckily they were acrylic and solvent weld was all it took.

Keep me updated on what you want to modify, I'll help as much as I can.

teravolt

Mon Jan 01 2007, 12:28AM

Registered Member #195 Joined: Fri Feb 17 2006, 08:27PM
Location: Berkeley, ca.
Posts: 1111

yah nylon cloth is a pane. rubber is good I used white neoprean. When I bonded them together I used contact cement and later I found that the cement conducted high voltage .

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob