Re: G10 rotor thickness / strange rotor materials

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Peter Terren" <pterren-at-iinet-dot-net.au> 

In my TC youth, I tried a number of similar things. The angle grinder disk
tended to short circuit track across itself and always seemed in danger of
cracking.  I used a angle grinder disc made of acrylic which softened and
distorted and one of polycarbonate that shattered at 9000RPM sending bolts
flying THROUGH my shed wall.  I always try to stay out of the plane of
rotation for this reason if working on it and in action have a shield to
contain any disintegration.
I now use Tufnol, a plastic laminate which is easy to work, thick, won't
shatter, takes some heat and looks safe.  I got it cut and drilled
professionally and it is much better balanced than I would be able to get.
At 9000RPM (break rate 1200 BPS) it needs to be really smooth in action.
Details on my site.
So the cheap option? Probably something quite thick (or multiple layer) eg
1/2 - 1 inch polycarbonate to compensate for the lack of strength and don't
ask too much in terms of rotational velocity (ie don't use 16 inch rotors)
Peter
  http://tesladownunder.iinet-dot-net.au/


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, May 13, 2004 11:59 AM
Subject: Re: G10 rotor thickness / strange rotor materials


 > Original poster: "Arpit Thomas" <arpit-at-inzo-dot-org>
 >
 > While waiting for my exams to end ( when I can go to the dump, and get 4
 > microwave ovens) I'm thinking of spark gaps. I might give a rotary spark
 > gap a shot. I don't have access to Fancy-pants codenamed materials like
g10
 > or anything  ;) , but I was thinking of gluing a large angle grinder
 > grinding disk to a washing machine motor, and having lots and lots of
bolts
 > through it. Would that work? Or am I going to have it explode on me? :/ I
 > cut a particle board disk with a jigsaw ( about 16 inch diameter) and
 > attached it to my 120 watt grinder- it was so poorly balanced it wouldn't
 > spin at more than a few revs per second though, so I thought about giving
 > premade disks a try :p (the particle board thing was really stupid in
 > retrospect ) :)
 >
 > Also, on a side note, Dr resonance were you responsible for that great
 > tesla coil in the questacon museum in canberra, australia ?
 >
 > *********** REPLY SEPARATOR  ***********
 >
 > On 12/05/2004 at 4:06 PM Tesla list wrote:
 >
 >  >Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>
 >  >
 >  >
 >  >You can go up to 3/4 inch to edge (not center) of bolt with G-10.
 >  >
 >  >Dr. Resonance
 >  >
 >  > >
 >  > > I'm about to make an 8 inch rotor from G10 material.  The disc will
run
 >  >at
 >  > > 1800 RPM and have 4 electrodes (120pps).  Given a brass bolt holder
 >  >(center
 >  > > drilled for a tungstan rod), what thickness is required for strength
and
 >  > > how far from the outer diameter of 8 inches should the bolts be
placed?
 >  > >
 >  > > I'm thinking of 3/8 thickness and bolts recessed 1 inch from the
outer
 >  > > edge.  Can I get closer to the outer edge?
 >  > >
 >  > > Many thanks?
 >  > > Gerry R
 >  > >
 >  > >
 >  > >
 >
 >
 >
 >