Re: Need Help With School Project

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Jim Lux" <jimlux@xxxxxxxxxxxxx>


----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Tuesday, March 08, 2005 9:34 PM
Subject: Need Help With School Project


Original poster: "M Duce" <mduce@xxxxxxx>

First of all I would like to thank all those that replied to me last time I
needed help.

I have now collected the following items:
NST - 12,000 V     30 MA
White PVC Pipe - 3.25 inches
Enameled Copper Wire - 24 AWG
Soft Copper Tubing - .25 inch diameter
Aluminum Dryer Vent Duct - 3 and 5 inch
2 Large Aluminum Pie Pans
Variac - 120 V    8 A - if of any use

My dad is helping me with any mechanical help, if I need it. I think that
now I am at the stage where we must wind the coil onto the PVC pipe for the
secondary coil. I am worried about the wire staying on the pipe. Should it
have lacquer applied to it? If so, what kind of lacquer or would it cause
the coil to arc across the windings. I was figuring a variable electric
drill to spin it. Does this seem good? We are thinking about doing about
900 turns of the wire. Does this sound alright?

>>>> sounds fine as far as turns go.  A variable speed drill will make the
winding go pretty fast.
>>>> Make sure the PVC pipe is nice and dry before you start (and check to
make sure it's not white drain pipe or landscaping drain pipe... if it's
Sch40 water pipe you'll be fine, but the other stuff is white on the outside
and sometimes black or foam on the inside). PVC melts at a real low temp, so
careful when drying.  Just make sure you haven't been leaving it out in the
rain for the last month.
>>>> I use little pieces of scotch tape every 50-100 turns to hold things in
place while winding.  When done, I spray the whole thing with clear Krylon.
Others have done things like put a strip of double sided tape down the
length of the pipe.  It is tacky enough to hold the wire in place while you
wind.
>>> If you get half way done, and the wire falls off... well.. that's part
of coiling.



Is my 30 MA NST powerful enough for this size of coil? I think I get my
hands on a 60 MA NST cheaply if necessary.

>>> 30mA is just fine, 60 mA is better, of course.


For my spark gap I am not really sure what to do. I am not sure weather to
use the rotary or stationary spark gap. Where would I find the plans for a
simple one?

>>> Start with a static non-rotating gap.  I'd suggest using 3 pieces of
3/4" or 1" copper pipe about 2" long, laid parallel.  If you arrange them in
a bit of a triangle (ascii art follows):

O   O
  O

You can attach the two HV wires to the two tubes forming one side of the
triangle, and then adjust the gap by just changing the position of the third
tube.

I am thinking about using a beer bottle capacitor. My dad has already
agreed to empty the bottles of Corona. []

>>>There's some good instructions on how to build this on the geekgroup(?)
website.

Would be grateful for any help or advice,
Mitchell