Re: Primary construction
At 10:42 PM 08/08/1999 -0600, Tesla List wrote:
>Original Poster: Erthwin-at-aol-dot-com
>I just went out and bought 100feet of 1/4" copper tubing for my primary, my
>TC is run off of a 7.5/30 NST and I have 4 strings of 10 capacitors at 0.05uF
>1kv each (that gives a final rating of 20kv -at- 0.01uF), I'll be using a 6"
>secondary ~25"-30" length so to achieve resonance I'll need something in the
>area of 14 turns in my primary (given a spacing of 1/8" between each turn) I
>was looking into possible frames to put the primary on and realized I might
>have a slight problem. I don't have a drill press or a table saw, anything I
>build is done with a hand held drill and a circular saw so obviously it's
>going to be rather hard for me to get the holes drilled with anything near
>precision and then trying to cut along the holes would be next to impossible
>to do without ruining the entire structure, any suggestions or alternate
At 1/8" between turns, it may be a llittle difficult to get a tap on the
primary plus you could run into problems with turn-to-turn arcing.
If it were me, I'd go 1/4" OD.
Home Depot offers pre-cut and ready-made 30" table-tops,
for the primary frame. You _could_ use a hacksaw to cut off
the tops of the primary supports (wood, HDPE) but that will
be a tedious job. A small jig-saw is well worth an investment
and they don't cost all that much nowadays. I could *not* have
finished my primary without using a jig-saw, either on the table
or the actual supports. I have a circular saw, but this isn't the
appropriate use of it on the table or the supports. I got a small
vise from a hardware store, clamped each support in the vise
and cut off the tops with the jig-saw. If funds aren't available
for a jig-saw, try asking around to see if you can borrow one.
Before I got the drill press, I used an awl punch to get the exact
center of each hole on the primary supports. That made it easy
to center the 1/4" drill bit and get nice clean precise holes in
HDPE plastic minus any of the flaking I had with drilling wood.
I am definately a convert to HDPE over wood. :-)
Go visit http://www.fwpd-dot-net/dona/tesla/teslacoil.htm and
see "Building the Primary" page.
"Resistance to tyrants is obedience to God" - Thomas Jefferson