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Re: Spinning pipes
Hi Daniel,
Tesla List wrote:
> Original Poster: Daniel Hess <dhess1-at-us.ibm-dot-com>
>
> >...I designed and built a squirl-cage RSG using ~6" x 1/2" copper pipe.
> >There are two disks with 8 pipes. Since the rotational force would be
> >great at high rpm, I built this with as tight a tolerance as possible.
> >The fixed electrodes are 5/8" spheres connected to a 5" x 1/2" bolt.
>
> Bart;
>
> Perhaps I mised this; What material did you use to make the two disks?
>
> Thanks,
>
> Daniel
The disks are not high tech. This design is a throw together to see "what
if", so I didn't go to the bank to build it. I used circular plywood from a
~12" wire spools. Wood is definitely not the choice regarding strength, and
especially if electrodes need to be secured into place. But with this
particular design, there are no set screws or anything of this nature
requiring "threadable" composites. I used plywood due to the layering
technique adding to the strength of the wood.
Regardless, it is still very important to drill the holes for the pipes as
"true" as any RSG. The pipe electrodes must be symmetrical to the center
shaft. I used copper 1/2" pipe end caps which I soldered to one end of the
pre-cut electrode pipes. Soldering was very neat as I didn't want any solder
protruding from the edges. I then inserted each pipe into the disks holes
until the pipe ends bottomed out. Getting the second disk on was the trick
as I had to fit very snug holes (all 8) at the same time on to the 8 pipe
electrodes. I carefully got it down on the pipes and soldered pipe end caps
onto the remaining open end of the pipe electrodes (pipe end caps had a hole
drilled into them on the ends for air flow). The disks were then slowing
moved each end of the electrodes. Around the shaft, are three triangular
holes which long bolts attach one disk to the other. 1" pvc pipe was cut to
exact lengths which are inserted between the disk. The long bolts protrude
through the pvc. The bolts are then tightened slowly until the two disks are
seated onto the pvc. This was to keep the disk parallel to one another. All
bolts (everywhere) were fastened with lock washers where applicable and high
temp loctite.
The center shaft I'm using is specific to the bearings used meaning the
shaft is a non-standard size and designed specifically for the bearings with
a tight tolerance. I don't expect this gap to be a permanent long life
setup. At high rpm, it might just fly apart. It is nice to have the strength
of two disks holding both sides of the pipe electrodes. Like I said, it's
just a test I'm doing on how an RSG of this type can perform in the old
"quench" arena. One good thing, it's very cheap to build compared to most
RSG's. But, if this did turn out to be a good performer, I wouldn't keep
plywood in the design.
Sorry if I rambled, I do that now then,
Bart