Re: cutting holes in gazing balls Re: Van de Graaff (fwd)

[Steven Roys <sroys@xxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 2 Jan 2004 10:40:14 -0500
From: Charles Brush <cfbrush@xxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: cutting holes in gazing balls Re: Van de Graaff (fwd)

>  > ---------- Forwarded message ----------
>  > Date: Wed, 31 Dec 2003 11:20:41 -0700
>  > From: Terrell Fritz <terrellfone@xxxxxxxxxxxxxxxxxxxxxxx>
>  > To: High Voltage list <hvlist@xxxxxxxxxx>
>  > Subject: Re: Van de Graaff generator safety question (fwd)
>  >
>  > Hi Ed,
>  >
>  > It is rock hard stainless steel, Probably need a grinder like a cut-off
>  > wheel in a dremal tool or die grinder.  Forget a hole saw unless it has
>  > cobalt alloy teeth no normal saw or drill bit will touch it.  Once cut, a
>  > belt sander can finish the edge.  I'll probably try it all an a little
>  > cheap one first.  If I were really desperate, I would have it waterjet
>cut.
>  >
>  > Cheers,
>  >
>  >          Terry
>  >



Terry,

Just a thought, but you might be able to use a stacked terminal
arrangement and completely avoid cutting one of those nice spheres.
The smaller terminal would have the hole, pulley, etc., while the
larger sealed terminal would just sit on top of it.  For instance
here is one rough idea I just put together:

http://www.VoltNet.com/temp/stacked_terminals.jpg

You'd have to play with shapes for field control, but it might be
worth a try before chopping up that gorgeous sphere (I am thinking of
getting one myself after seeing your photo!).  A rounded cylinder
could be good to.   Something like the pelletrons use:

http://www.pelletron.com/charging.htm

http://www.nr.titech.ac.jp/~iga/pelletron/pelletron.htm

http://www.phy.ornl.gov/hribf/accelerator/tandemweb/index.html


Zap!

Charles Brush