Re: van de graaff tube (fwd)

[<sroys@xxxxxxxxxxxxxxxxx>]

---------- Forwarded message ----------
Date: Thu, 2 Dec 2004 12:21:45 -0700
From: Gomez Addams <gomez@xxxxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: van de graaff tube (fwd)


On Dec 2, 2004, at 8:09 AM, High Voltage list wrote:

> Original poster: <sroys@xxxxxxxxxxxxxxxxx>
>
>
>
> ---------- Forwarded message ----------
> Date: Wed, 01 Dec 2004 16:47:12 -0800
> From: Ed Phillips <evp@xxxxxxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: Re: van de graaff tube (fwd)
>
> Ed:
>
> We were only running at 2,100 rpm so, at 3450 rpm, your current would 
> be
> higher.  These values listed were from the direct terminal to ground
> measured short circuit current.
>
> At 3450 the bearing noises become rather high for my liking.
>
> Dr. Resonance"
>
> 	Thanks for your note and for Antonio's.  As for the bearing noise, I'm
> running small ball bearings and as you say the noise is almost
> unimaginable!  When I rebuild this machine I'm going to use oilite
> bearings which will last longer than my interest in the thing and which
> should be pretty quiet.
>
> 	This thing was intended to be the prototype for a much larger machine
> which never got built.
>

Clearly, one should use the largest pulleys one can, so as to achieve 
the greatest belt surface speed for a given RPM.  ABEC 6 roller 
bearings should give fairly low noise.  One might also try polished 
stainless rod running in a Teflon block.

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