Re: Machining G11

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

Original poster: "Daniel Hess by way of Terry Fritz <twftesla-at-uswest-dot-net>" <dhess1-at-us.ibm-dot-com>


Steve, Jim, all;

Thanks for the feedback regarding machining G11. Funny thing is I meant to
reply off-line but must have hit 'reply' without thinking and my note went
to the list. The tip about using diamond-tipped machine tools came from a
manufacturer's data sheet which is available from McMaster-Carr's website,
where I purchased the stuff. BTW, the G11 was only slightly more expensive
than the G10 but can withstand up to 500 F vs. 350 F for the G10.

Several others have shared their experience (Bert Pool and Wild Bill Emory,
to name a few) and have related that it's a real chore but it can be done
at home.

I think at this point in my Tesla coiling career I'm going to opt to have
the work done professionally. I know it'll cost a lot more but (I hope) the
tradeoff will be a bullet-proof RSG that will withstand many future coiling
projects for years to come. Don't know if because of my German blood
(precision) or because I'm a Virgo (meticulous) but those who have seen my
coils know that I have a penchant for above average craftmanship. I know my
limits and short of buying my own milling machine, feel that having the
work done professionally is the way for me to go.

My plans for an RSG are based on Bert Pool's impressive design; An aluminum
ring 12" outer dia. x 9" inner dia. x .25" thick will be mounted to the G11
disk and will have holes about it's surface to accept the electrodes which
will be secured by setscrews threaded edgewise. (as candles on a birthday
cake). Two aluminum standoffs will hold the stationary electrodes. I'm
still undecided about a method to allow for mechanical phase adjustment of
the motor and welcome any suggestions in this area. This particular motor
frame doesn't have the traditional cradle mounts. The end plates of the
motor are flat but have drilled & tapped holes in them so maybe I can mount
something here. The motor is a 220 volt, 1/3 hp. (I have two of these
motors in case on fails or I screw it up I'll have an identical spare).

Daniel


"I made my own 1/2" G10 rotor with nothing more than a band saw to rough
cut
the rotor and a rotary die grinder (like a big Dremel tool) with a tungsten
carbide cutter for fine machining. I almost gave up trying to get the rotor
perfectly round and almost took it to a machine shop, but I was determined
and eventually thought of a way to do this myself. The rotor turned out
very
well and I would estimate is within a few mils of being perfectly round. If
you are interested in my technique I can tell you about it."