[Prev][Next][Index][Thread]

Re: weird primary design

Matt,

Actually, I managed to nicely wind my first primary last Friday.  I did
spend a lot
of time making nice supports and fastening them to the base really well.  I
don't
have pictures on a Web page, as I need to set one up, and I don't have time
now (too
much coiling to do!).  Give me a couple weeks, and I'll post a web address
to the
list when I get one done.

I drilled 23/64" holes in a sheet of 1/2" polypropylene (I THOUGHT I was
getting the
clear stuff, but I got translucent.... should have just used HDPE.) for my 3/8"
copper refrig pipe.  (I measured the OD of the copper to be .365".)  I cut
the top
of the holes off a little above the ceneter of the circle.  I mounted the
"L"-shaped
supports (the strike rail goes on one leg) with #6 flat head wood screws that I
countersunk ~1/16" below the surface of the plastic.  I slowly and gently
formed the
primary tubing (preforming the tube about a turn+ in advance).  I had to
*slightly*
crimp the tubing to fit into the holes (after all, the holes are about
.008" too
small) before pressing the tube into the holes.  I bent (using a vise-grip)
the end
of the inner turn 90degrees down to fit through a set of slots I made into the
plywood base.  I'll either ream out the tube (the cutter crimps the tubing) and
solder my 4AWG cable (free from American's audio instl. dtp.) into the pipe, or
crimp the end flat, and drill a hole for a non-permanent connection.

I know a picture is worth a thousand words, so I'll send you (Matt) a picture
off-list.

A nice-looking primary is possible with a little patience and few tools.  I
used a
radial-arm and band saw, a drill press, a belt sander, and a pair of
vise-grips,
though with a little more time and effort, a hand drill, hand saw, and
sand-paper
with a block of wood could be used.

Mark B.


Tesla List wrote:

> Original Poster: Terry Fritz <twftesla-at-uswest-dot-net>
>
> Hi Matt,
>
>         Darn...  When I first started winding primaries, mine were all
messed up
> too...  They still work fine.  the electricity does not care as long as
> they are not all shorted and touching.
>
> I start with a new roll of 1/4 inch refrigeration tubing and carefully
> remove the box from the roll without disturbing it.  I then set it on the
> coil form and slowly expand it just enough to set were it needs to go.  I
> try and work with large sections and bend it just the minimum needed to
> place it.  I usually lays in place with minimum bending and stays in pretty
> good shape.  There have been a few times when I pull the mess off, wad it
> up, get another roll, and start over...  When you buy to role, eyeball it
> pretty good to be sure it is in good shape to start with.
>
> I wish I could say more to help but that is all the advice I know to give
> on laying primary tubing.  I wonder if anyone has really done a great job
> at it the "first" time???  If so perhaps they know more tips??
>
> Cheers,
>
>         Terry
>
> At 04:04 PM 03/18/2000 -0500, you wrote:
> >the copper tubing was all out of shape and i had to fix it.now its all bent
> >and crapy looking.
> >