Re: Advice on Primary

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: robert heidlebaugh <rheidlebaugh@xxxxxxxxxxxxxx>

Ben: I have used holes and I have used notches. Once you use holes you will
not do it again. It is much harder to do. Make shure your holes are a little
larger than your tubing to allow for the curve in the coil radius. Thread
your frame around your coil of tubing and do not unwind your coil. Sone
copper is anealed soft and easy to use. as copper is worked or stored it
gets hard. You can bake hard copper in youe oven at broil heat for 2 hours
then drop it in cold water to aneal the copper . Un-like steel copper is
left soft when quenched steel is left hard. That probibly is not required
with holes large enough or slots. Slots are much less trouble.
      Robert   H
--


> From: "Tesla list" <tesla@xxxxxxxxxx>
> Date: Tue, 22 Feb 2005 20:00:53 -0700
> To: tesla@xxxxxxxxxx
> Subject: RE: Advice on Primary
> Resent-From: tesla@xxxxxxxxxx
> Resent-Date: Tue, 22 Feb 2005 20:01:20 -0700 (MST)
>
> Original poster: "Ralph Zekelman" <gridleak@xxxxxxxxxxxxxx>
>
> Ben,
> Do not unwind the coil of tubing and don't try to feed it thru the
> holes. Notches are fine. It sounds like you have gotten into hard-copper
>
> refrigeration tubing which is NG for coil winding. You want the soft-
> copper tubing as used for house plumbing. I have used 1/4  inch
> tubing and it's probably OK at lower power levels like maybe the
> 2.25 kW that I run, but it does get a little warm. I'll use 3/8 if I
> ever
> boost the power. Looking at the photo, I would cut notches just
> wide enuff for a slight force fit of the tubing down into the holes.
> Start from the inside and unwind the coil as you work your way
> to the outside turn. No problem in splicing the tubing. Two good
> ways to do this: You can sweat solder a piece of  the next size
> larger tubing over the two ends, or, you can sweat solder a piece
> of solid copper wire inside the two ends. Somewhere I have the
> equation for determining the length of tubing needed but it is
> faster to just splice the ends if needed.
>
> Much of the fun is in the learning. Don't be afraid to make miztrakes.
> Good luck on you project.
>
> Ralph
>
> Original poster: "Medina, Benjamin (UMR-Student)" <bamxbb@xxxxxxx>
>
> Hello,
>
> I know this topic has already been discussed but I am still having
> doubts
> when it comes to the winding of the copper tubing through the holes or
> notches of the supports. So if someone could clear this up for me that
> would be very much appreciated.
>
> As of now this is what I plan on using:
>
> 1. A 50ft roll of 1/4" OD refrigeration copper tubing.
> 2. A 3/4" thick sheet of plywood as the base.
> 3. 5 supports in an L shape cut out from a cutting board I got at
> WAL-MART
> fixed to the plywood base with screws (similar to the image below).
>
>
> http://hot-streamer.com/temp/Medinaimage001.jpg
>
>
> At first I thought of fixing the supports to the base and winding the
> tubing through the holes, but now I am realizing it will be a PAIN!!
> Therefore, should I slide in the supports, starting at the center and
> work
> my way outside, through the entire roll of tubing? Or should I start at
> the
> ends and work my way inside?
>
> Some people prefer holes in the supports; others prefer notches. I am
> not
> sure about this. I am thinking that the notches might bend the tubing if
>
> one is not careful when doing this. Any suggestions?
>
> Say I want 15 turns. While winding the tubing, let's say I run out of
> tubing on the 11th turn. Is it okay to solder another continuous piece
> of
> tubing to the original, to complete the 15 turns or not? I guess, what I
> am
> asking is if I need a continuous roll of tubing or not? Will this affect
>
> the coupling and/or the overall performance of the TC?
>
> Another thing I noticed is the fact that the tubing is double wounded,
> making it even more tedious to work with it. A guy at Home Depot
> suggested
> to unroll the tubing on the floor and then wind it on/through the
> supports.
> Any suggestions?
>
> I appreciate your time. Thanks for the help.
>
> Regards,
>
> Benjamin Medina
> Rolla, Missouri.
>
>