Re: shaft fasteners for RSG?

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

Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com> 


Don't consider Lexan for a large high power coil.  The heat will start to
melt the Lexan and send sparkgap shrapnel flying around.

Use 1/2 inch dia. G-10 phenolic.

A good design would be a 14 inch dia. G-10 rotor with 12 electrodes on a
12.5 inch dia. circle.  Use a cheap surplus DC treadmill motor (usually 2-3
hp) with a pulley and belt for reduction in speed.  Most of these motors top
out around 3,000 RPM with a light load.

Set the pulley reduction ratio to give you approx 600 pps (maximum) from
your rotor.  Power the DC motor with a standard 120 V 25 Amp rectifier block
and use a healthy filter cap on the output for smooth DC power.  Use an RF
"hash" choke between the DC output and your motor to choke off any RF that
might feed back due to any spikes or induced currents in the sparkgap --
motor case.  Use one on both pos and neg legs.

The treadmill motors are $30-$75 range or less thru surplus houses.

This allows you to adj speed and pps for best results with your coil.

Have a machinst to the layout and setup on the rotor (.0005" tolerance) and
then static balance it.  Don't do this at home as a do-it-yourself thing.
The rotors are a dangerous part of a coil setup and a quality machine shop
will do an excellent job.  Safety first --- it's a bit expensive but a lot
cheaper than buying one of your neighbors a new eye.

We can machine you a rotor hub if you need one.  I would need to know the
shaft size on your motor.  Then take this and your G-10 to a local shop and
have them do the rest.

Dr. Resonance
 >
 > I have started getting the urge to build a big coil again and
 > I was wanting to do everything right this time. In the past,
 > I simply used a bench grinder motor with the emory wheels
 > removed and replaced with a lexan disc(s). I used the ex-
 > isting emory wheel arbor to secure the lexan disc but I
 > want to use better hardware this time around. I've noticed
 > that most of the professional built RSGs have a sleeve or
 > bushing cylinder that appears to go over the shaft with
 > set screws to secure it to the shaft and about 4 set screws
 > that secure the disc to the sleeve bushing. Home Depot
 > and Lowes don't carry anything like this and I was won-
 > dering where to get this type of shaft hardware (McMaster-
 > Carr, I assume) and what name would it be listed under?
 > I know that you can get G-10 sheets at McMaster-Carr
 > also, but I found that I could also get G-10 at one of my
 > local plastic suppliers for about 60% of McMaster-Carr's
 > price.
 >
 > Thanks,
 > David
 >
 >
 >