Re: physically large coils

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>

Hi Jim,

The secondary should be open frame, rigid, light weight, and 
non-conductive. Obviously, rods can be used between sections.

Each section must be "fastened" together nice and tight to ensure a 
rigid framework. This is the most challenging.

The insides of each section are not available. With this in mind, 
either the top and bottom supports are ring style with fastening 
crossmembers, or, the top and bottom rings are designed so that when 
a section is placed on top of another section, pins sticking out 
perpendicular at the ring edge enter a channel in the lower ring 
section. A twist and lock approach.

One of the protruding dowel pins could serve as a connection and seat 
into a connection socket at the end of the channel. The top and 
bottom supports need to be machined with some precision.

I envision a 2" gap between sections (without wire) simply to support 
the fastening of sections.

The real advantage about a sectional approach is shipping (each 
section could be crated and protected).

Anyway, something along those lines.

Take care,
Bart



Tesla list wrote:

> Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx>
>
>
> The whole area of "how do you build a big coil that can be moved 
> conveniently" is a fascinating one.
>
> By now, it's fairly straightforward to build a pig powered coil with 
> a 12-16" diameter secondary and having it work fairly well "out of 
> the box" (assuming you've built a few coils before, and you are 
> reasonably careful with the models).
>
> The problem is that the thing is going to be a beast, and 
> non-trivial to move around.  Not everyone has a big panel truck in 
> which to transport their coil. Although, I have seriously thought 
> about getting a small trailer to build a big coil on, and then 
> parking it at a RV storage yard.
>
> So, you look to designs like that one in England that had the 
> nesting secondary segments, or something that can at least breakdown 
> into "carryable by one person" chunks (e.g. the OSHA 55 lb, 25kg 
> one-person-lift limit).
>
> You also want something that won't take 8 hours to assemble, and it 
> needs to be fairly rugged after assembly.  Say you had your 16" 
> diameter secondary, and it's say, 7 ft long overall.  You could 
> break it into 2 foot segments that lock together with some sort of 
> electrical connector (a sort of nontrivial design exercise in itself)
>
> What about the 4-5 ft diameter primary?  Can it be made to collapse/fold/stow?
>
> The HV supply can be made fairly small and light.
>
> Think about "how would I fit this whole thing into the back of a 
> station wagon"