Date: Wed, 20 Feb 2002 18:04:49 -0500

Author: Sam Sampere

Subject: Re: VDG recommendation


I have one of the old Cenco (no longer in existence) VdGs that I use for most
demos too, i.e hair raising. It works great and I'm now in the process of
making a new column. The original one is nearing the end of its useful life.

I ordered a replacement belt from Sargeant Welch last summer. The new belt was
crummy looking, had many voids in the rubber, and the edges were jagged. It
didn't even charge very well, so I threw it out and put the old belt back on.
SW refunded the money, but didn't do too much to inquire about my lack of
satisfaction. The model they offer in their catalog is a little different than
the original Cenco model, and frankly, I'd be a little hesitant to buy it. I
would buy one of the original Cenco ones though.

I had a Science First one and that worked fine. I loaned it to a high school
teacher and never got it back. Shame on me! Live and learn. If I recall, you
need to get a ground sphere; it's not permanently attached like the Cenco
version is.


brian holton wrote:

> I have been hesitant to chime in, but I have used the CENCO unit for five
> years now and it has seldomly let me down. It has on occasion, in NJ the
> weather can be very wet at times, but overall, I have been very pleased. I
> have run the unit for hours on end with kid shows and it just keeps on
> taking the abuse. There have been times when it functioned poorly, but
> outside, by a pool, on a damp day, well one might expect that! I've even
> seen Van de Graaff's Van de Graaff function poorly at Princeton a number of
> occasions! They have one of the originals you know.
> One question, we had some discussion a year or so ago about large domes.
> What is or was the outcome of that for people that wanted to make their own?
> Brian Holton
> -----Original Message-----
> From:
> []On Behalf Of Jerry DiMarco
> Sent: Wednesday, February 20, 2002 11:41 AM
> To:
> Subject: Re: VDG recommendation
> Thanks for the suggestions. It will be hard to make a choice. The
> Pasco VDG has some nice features, but claims only 4" sparks. A 1999
> brochure from Science First shows a 400kV unit that delivers 12"
> sparks! When I went to their website I could find only a smaller 200kV
> unit. Is the large one still available, and does it really spark 12"?
> Jerry
> At 2/20/2002 09:49 AM, you wrote:
> >I was in error in mentioning that the Van de Graaf we bought in 2000 was
> >manufactured by Winsco. It was manufactured by Science First.
> >
> >* * * * * * * *
> >
> >Mike McFarland
> >Resources for Instructional Labs and Lectures
> <><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
> Jerry DiMarco
> Manager of Lecture Demonstrations and Instructional Labs
> Physics Department, Montana State University
> Bozeman, Montana
> ph: 406-994-6161
> fax: 406-994-4452
> Our Motto: "We don't use anything the way it was meant to be used"