Re: Building the Primary Coil

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

Original poster: "Shaun Epp by way of Terry Fritz <twftesla-at-qwest-dot-net>" <scepp-at-mts-dot-net>

Hello Pat,

I just finished building a tesla coil and its almost working, but it blows
up capacitors with excessive voltage... :-((    But my primary is a buet!!
I used 8 supports, I drilled holes in all eight, 11 holes per support, then
I used a band saw to cut from the top down to where I drilled them.  I
followed this by using a drill press the passed the support slot through to
make sure that the slots were wide enough to accept the copper tubing.  The
primary was set 1/2 inch center to center and was 1 inch spacing away from
my secondary, I've heard you can use less.

Now the details for the supports.
  first off I assumed that I would physically mount all the supports at the
same distance from the secondary.  So I used 1/4" in from the edge of the
first support for the first hole, then the other supports in sequency as
follows(the supports are already mounted away from the secondary).  So each
turn is 1/2" c-c from the other, that means that around each turn on the
coil you must transverse a total of 1/2", right?.  If you are using 4
supports, the 1/2" divided by 4 is 1/8" extra per support.  So support #2 is
1/4 + 1/8 = 3/8",  Support #3 is 3/8 + 1/8 = 1/2", and support #4 is 1/2 +
1/8 = 5/8". Mark these as these will be your first inside holes on each of
your four supports.

To drill all these holes requires lots of patients!!!!  So what I did is I
picked up a template, 1/2 inch spaced plastic sheet grid from a hobby supply
store, I think they use them for model trains.  I then drilled at each 1/2"
on the template, you need to figure a hight /depth first.  Then I placed the
template down on the support, line it up on the first hole and mark the
other holes.  I used a automatic punch to mark the holes, they're about
$15 -$20 in a hardware store, to use then you just press down and bang, one
dent.  Do this to all 4 supports, drill pilot holes, then the right sized
holes for you copper tubing.  I used 3/16 " tubing... the soft stuff from a
refridgeration store, and drilled the holes one size bigger.  Then using a
band saw, cut out the slots leading down to the holes.  Some people cut them
for a tight fit with the tubing, that way you won't have to fasten down the
tubing.

Then mount the supports, carefull not to mix up there order, after that just
lay the copper tubing into the supports.  I went inside to outside and I
left the copper tubing in the spiral as it came.  After that some minor
finger adjustments is all that was needed.  Note if you use more supports
(8) it will be neater.

Good Luck with it,
Shaun Epp

P.S.  I hope this isn't to detailed, no offense intended if I went to far.


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, October 31, 2001 6:41 AM
Subject: Re: Building the Primary Coil


> Original poster: "Patrick Bloofon by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <transactoid-at-home-dot-com>
>
> My question was more meant to address the issue of how people make their
> spacings on whatever they use to space the turns. I'm really bad with
> "visualizing" construction plans. If you have say, 4 supports, you don't
> just drill equally aligned holes up the supports do you? In order for it
to
> spiral, won't each supports' holes have to be offset from the previous
> one???
>
> Sorry if this is a really simple question. I just cannot picture this in
my
> head....
>
> Thanks,
> Patrick.