[TCML] Re: Coil V1.0 Arc over between turns of secondary.

[Joe Mastroianni <joe@xxxxxxxxxxxxxx>]

Hi Brandon,
Unfortunately, I did not take pictures as I went along and it's sort of all finished now.  But I can tell you what I did.

First and foremost - there is absolutely nothing wrong with the secondary I bought.  It would have worked fine as advertised, and it works fine despite my lousy tuning making it arc.  I think it's a testament to the workmanship that it held up against all my newbie foul ups and I would not hesitate to recommend it to anyone else building a coil who doesn't want to wind a secondary themselves.

That said, all of my reading suggested to me that having the topload and ground connections appearing INSIDE the secondary core was generally a less good design than sealing up the secondary core and having the connections run along the outside.

What I did was to follow Dan McCauley's design.   I bought 2 pieces of 1/2" thick PVC, each 6" square, from McMaster Carr. (P/N 8747K635) Using a drill press and a circle cutting tool, I cut 2 PVC circles that would fit exactly inside the secondary tube.

Then, I very carefully pried the wires from the inside of the tube.  The manufacturer had drilled 6 1/32" holes in the side of the tube, three at the top, and three at the bottom.  He then threaded the secondary wire through those holes in an "S" pattern - from outside to inside, back outside, and back inside again.  Did this both at the top and bottom.  Then he taped the slack to the inside wall of the secondary with painter's tape.  

I put a spot of cyanoacrylic glue at the point where the last turn of the wire went into the first hole so the secondary wouldn't be tempted to unravel.  Then, using a small sharpened wooden dowel I pried the wire out of the holes.  I then plugged up the holes with a very small amount of epoxy.  Then I wrapped the remaining slack around the secondary core in a very loose spiral (as I have seen done in other's coils) and glue it down with cyanoacrylic cement.  

Did this for both top and bottom.

Then, I drilled the PVC "end caps".  I made one hole exactly in the center for the top of the secondary, and I put 2 holes in the bottom.  I epoxied into these holes 1/4"-20 nylon bolts so that their threaded ends stuck outside the secondary core.  Once that epoxy dried enough, I epoxied the PVC plugs into the top and bottom of the secondary core tube so that they were flush and waited overnight for everything to dry.  Now I had my secondary plugged at both ends with PVC, and with threaded nylon bolts sticking outward from both sides. 

On the bottom of the secondary, I stripped the wire with a bit of sandpaper and then soldered the secondary wire to a small square of copper plate which I epoxied to the outside of the secondary tube below the last tight turn of the secondary windings.  On the top, I epoxied a copper disc to the PVC and then soldered the top wire to it.

Thus, the top of my secondary was now an exposed copper disc connected to the top of the secondary.  On the bottom, I had 2 threaded nylon rods sticking out and the copper plate epoxied to the side.  

I mounted the secondary to the space in the center of my primary by drilling 2 holes and inserting the nylon bolts through the holes.  I made the ground connection by soldering a piece of 12ga copper wire (romex) to another copper plate, and pressure fitting it against the plate on the secondary with nylon wire-ties.  Not so elegant, but functional.

On the top, I just slid the  toroid onto the single nylon bolt and it made contact with the copper plate on top. 

I'm not sure that sounds easy, but it was.  It just took a whole lot of time, and honestly, I probably could have done a better job of it.  

If desired, I'll take pictures of the final result and post somewhere.  I just didn't think to take illustrative pictures as I was going along.

All the best!
Joe


On May 31, 2010, at 11:00 AM, tesla-request@xxxxxxxxxx wrote:

> Hi Joe,
> 
> Could you go into greater detail on how you performed your secondary makeover? Possibly post some pictures if you already have them?
> 
> Thanks a lot,
> Brandon

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla