RSG opinions?

From:  D.C. Cox [SMTP:DR.RESONANCE-at-next-wave-dot-net]
Sent:  Tuesday, April 07, 1998 6:28 AM
To:  Tesla List
Subject:  Re: RSG opinions?

to:  Richard

The 6 inch rotor size will work fine with 1/8th to 3/16th inch tungsten
(2%) at 3-4 kva, however, you would require a larger diameter such as 1/2
inch dia. for the 10 kva unit.  The 10 kva unit should use 1/2 dia. brass
or tungsten thru the plate and contain approx 8-10 electrodes for the speed
you are running.  Calculate and set to 350-380 pps for best results with
most classical coils.  Don't use stainless or steel on RSG's -- the peak
current is too high and this material will dampen it considerably with the
short pulse cycle in microseconds.  Have a competent machinist make the
rotor for you so it spins true without wobble.


> From: Tesla List <tesla-at-pupman-dot-com>
> To: 'Tesla List' <tesla-at-pupman-dot-com>
> Subject: RSG opinions?
> Date: Sunday, April 05, 1998 11:13 PM
> ----------
> From:  RMC [SMTP:craven-at-globalnet.co.uk]
> Sent:  Sunday, April 05, 1998 4:37 PM
> To:  Tesla List
> Subject:  RSG opinions?
> I can buy a new 6" bench grinder in England from B & Q for twenty
> quid.
> It is a 3000rpm  half-HP motor (synchronous, I believe i.e. not a low
> slip induction motor) and is intended to run a pair of grinding disks
> (one on each end of the motor shaft).
> If the effective mass of the RSG disk is less than or equal to that of
> the grinding wheels it is replacing (such that torque loading will not
> change), I might be able to modify the bench grinder to take at least
> a 9" or even a 12" disk.
> My intention is to make a couple of disks from Tufnol or similar rigid
> insulator, with 12 contacts. The contacts will either be
> tungsten carbide machine tool inserts    or
> Copomel tungsten/copper (70/30)
> these two materials cost less than elemental tungsten but have similar
> relevant properties i.e. they don't melt and they're very hard. The
> expense
> is still high and it means that it might be better for me to buy a
> ready-made
> RSG from BillWysock, for example.
> I will have four static contacts such that the switching path is onto
> and off both wheels: 4 series breaks. This could be doubled up by
> then going back through the disks on an opposite contact, so to speak.
> This might negate the need for A Richard Quick cylinder quench gap.
> It's for a 10kV primary running at 3-4 kVA upto 10kVA.
> I would welcome :
> 1. Comments on using 2 wheels and upto 4 or 8 breaks in series
> 2. Comments on Copomel vs tungsten carbide vs tungsten vs thoriated
> tungsten at 10kW
> 3. Comments on using 6" diameter rotors
> Any comments or criticisms would be very welcome. My first RSG was a
> bad job due to poor motor end-float and the fact that I used stainless
> steel. And the fact that I'm not a mechanical engineer.
> Richard Craven, Malvern, England.