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

1/4" Tubing Sphere



Here are the specs on my 12" diameter sphere just incase someone else is
interested too.

I discovered that I could not hand bent the tip ends of the 1/4" tubing so I
cut all the tubing pieces 2" too long and then cut 1" off each end after it
was bent.

I wrapped most of the tubing around things like 1 gallon can, V belt pully,
soup can, etc.  But there were a few tubes that I could not find anything
the correct size to wrap it around so I cut out plywood circles to wrap them
around.

Its best to bend the circles a little small so they can be stretched out.
The metal springs back and hold the ends together and it make it much easier
to solder them together.

After bending each tubing circle I cut off the ends and soldered them
together. 

I figured an end to end solder joint would not be strong.  I put 4 pieces of
#14 solid copper wire about 1" long on the inside of each solder joint to
make it stronger.

I have 29 copper tubing circles.  The circles are spaced 1/4" apart.  

1 circles are 12" diameter
2 circles are 11.990"
2 circles are 11.875"
2 circles are 11.750"
2 circles are 11.375"
2 circles are 11.000"
2 circles are 10.500"
2 circles are 10.000"
2 circles are 9.250"
2 circles are 8.600"
2 circles are 7.800"
2 circles are 7.000"
2 circles are 6.200"
2 circles are 5.250"
2 circles are 4.300"

The 4.300" circles fits almost perfect on the top end of my secondary coil.
Its not attached, it just sits on top of the pvc pipe. 

The hardest part is soldering all the circles together.  I used 3 pieces of
1/4" copper tubing as spacers to hold the circles in place while I soldered
them together. Then I removed the spacers. 

I bent 6 pieces of copper tubing on a 5.687 radius.  The pieces measure
11.250" long end to end after they are bent.  I put these pieces on the
inside of the sphere and soldered them to all 29 tubing circles.  These
pieces run up/down or 90 degrees to the circles.

Some of the sparks come off the sides, and some off the top, no sparks off
the bottom.  

Thats about it.

If I had it to do over I think I would use only 11 tubing circles.

1 circles are 12" diameter
2 circles are 11.990"
2 circles are 11.875"
2 circles are 11.750"
2 circles are 11.375"
2 circles are 11.000"

I could solder them together and have a toroid shape instead of a sphere
shape. I would have the advantace of getting a 12" radius on the edge of the
toroid like the sphere. I don't know if this is a good idea or not.  Might
be worth an experement.  Could always add the other 18 circles later.

Gary Weaver 
                          ____
                   ______/       _____
      __________ _/      \______/
     (__________) \___         ________ 
         |  |         \_______/        \_________
         |  |                 \_____
         |  |           
         |  |    
         |  |    
     ============