RE: Tufnol

Hi Mike, and all,
                      I have just built an 8 stage series compound RSG using
1/4" Tufnol sheet.

I guess it all depends on how big a disk you want to cut, what speed you
want to run it up to and how many electrodes at what weight you want to

Put it this way, mine hasn't exploded yet, though it is yet to have H.T
across it!

I have to say that I found the learning curve on RSG construction very steep
My rotor is pretty small at 160mm and the electrodes and their holders weigh
less than 40grms a piece.  Even so, at the maximum speed of the motor, (6000
rpm) their mass turns into an equivalent weight of many Kilogrammes once
centrifugal force does its bit!

The type I used was Kite brand, but only because I had some to hand.
Apart from the obvious electrical performance, you want something with a
good shear strength. 
Kite brand isn't bad, but tufnol 10G (fibreglass) is much better.
1/4" is a bit on the thin side, but is ok for very small rotors I think.

The biggest problem I had was in getting the thing to run true on the motor
There are many different design strategies, but they all make heavy demands
on most peoples engineering tolerances.
Unfortunately errors are pretty unforgiving at narrow electrode clearances.
(It explodes!)
Also beware of resonance's in the disk of the rotor at high speeds.
A nice 16 thou gap when stationary may suddenly close up when you hit a
certain speed (it explodes again!)

I think I'm still someway down that learning curve BTW!

  Good Luck!    Martin Dale  TCBON

> ----------
> From: 	Tesla List[SMTP:tesla-at-pupman-dot-com]
> Sent: 	Sunday, January 03, 1999 12:13AM
> To: 	tesla-at-pupman-dot-com
> Subject: 	Tufnol
> Original Poster: Michael Tucknott <Michael.Tucknott-at-virgin-dot-net> 
> Hi all
> Thank for all the reply's about "Tufnol" and not tufnell.
> I promise I will learn to spell one day.
> Now next question would a Tufnol disk between 1/4" and 1/2" make a good
> rotor for a RSG.
> Cheers Mike Tucknott
> --------------------------------------------------------------------------
> ---
> "He tames the thundering bolt of jove and annihilates time and space"
> Nikola Tesla 1906 
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> ---