RE: Coil Form needed

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

Original poster: "makinglightning comcast" <makinglightning-at-comcast-dot-net> 

I put 2x4's in the form of a cross on the inside of the ends, then drilled a
hole through the middle with a pipe going through the middle.
I use bungee cords sewed together that wrap around the tube and then down to
a geared motor. I put a layer of friction tape on the end of the tube for
the bungee cord to grip on.


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, May 13, 2004 10:02 AM
To: tesla-at-pupman-dot-com
Subject: RE: Coil Form needed

Original poster: "Arpit Thomas" <arpit-at-inzo-dot-org>

wow, thats not bad at all! I paid 20 dollars for one metre of 6 inch pipe :/
So where do you get the end caps for them? I'm assuming you'll need end
caps so you can atach it to a winding machine. 6 inch end caps are about 25
bucks each at the local hardware store- all the 6 inch fittings are very
expensive.

*********** REPLY SEPARATOR  ***********

On 12/05/2004 at 10:00 PM Tesla list wrote:

  >Original poster: "makinglightning comcast" <makinglightning-at-comcast-dot-net>
  >
  >Paul,
  >
  >I have been able to go to a construction site and just ask some guys there
  >for a piece. Usually an 80 foot 12" is just scrap to them. I got 2 12" 15
  >footers for a case of Bud once. I got a 12' 18" one for free also. Those
  >are
  >harder to come by, but the 12" ones are used all the time in new
  >subdivisions and commercial buildings. They sure are building a lot
  >nowadays, so it should be easy for just about anyone to do this.
  >
  >Kevin
  >
  >-----Original Message-----
  >From: Tesla list [mailto:tesla-at-pupman-dot-com]
  >Sent: Wednesday, May 12, 2004 6:03 PM
  >To: tesla-at-pupman-dot-com
  >Subject: Re: Coil Form needed
  >
  >Original poster: DRIEBEN-at-midsouth.rr-dot-com
  >
  >
  >
  >----- Original Message -----
  >From: Tesla list <tesla-at-pupman-dot-com>
  >Date: Wednesday, May 12, 2004 9:20 am
  >Subject: Coil Form needed
  >
  >  > Original poster: "Paul Marshall" <klugmann-at-hotmail-dot-com>
  >  >
  >  > I am looking for a coil form 12" or greater diameter. The length
  >  > should be
  >  > about 4 times the diameter. Also I am planning on using a 40kV
  >  > .5uF
  >  > capacitor for the tank circuit. I have a 25kVA pig to drive it.
  >  > Has anyone
  >  > on the list ever used that much capacitance in their tank circuit ?
  >  >
  >  >
  >  >
  >  > Paul S. Marshall
  >
  >Paul,
  >
  >I would think that 0.5 uFD would be way too large for
  >anything except maybe for an Electrum sized coil. The
  >biggest cap that I've used so far is .0825 uFD, but I
  >do now have (2) 0.1 uFD, 50 kV Hipotronics custom Tes-
  >la caps that I got from Jeff Parrise of KVA Effects.
  >I plan on using one of these for my future BIG coil
  >project and driving it with a 15 kVA pig.
  >
  >As for large diametered secondary coil forms, I was
  >able to get gray PVC ducting pipe from a local plas-
  >tics supplier. I had picked 12" but they had 18" too.
  >Of course it was quite pricey, though. I payed over $5
  >a foot for the 12" and I'd hate to even ask how much
  >the 18" was ;^0 Another cheaper alternative is the
  >concrete former tubes. They are cardboard and are
  >considered to not be the best form material due to
  >higher lossiness and low Q, but if thuroughly dried
  >and varnished, they do work. I know from experience.
  >My biggest coil to date used a 12" dia cardboard
  >"Quiktube" concrete fromer from Home Depot and it
  >was only about 38.5" long but gave 8 to 10 ft. sparks
  >from a 9x30 toroid and driven by a 10 kVA pig (14.4 kV)
  >and with the aforementioned .0825 uFD primary capa-
  >citance and a homemade lexan and brass RSG.
  >I've seen 24" concrete formers at construction sites
  >so you could definitely build a large coil with one
  >of these.
  >
  >David Rieben