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Step 3Make the inner ring assembly
Now we have to make the inner ring. This is a clear ring that is held by a frame (which I call the lower spider frame.)
First cut the inner ring from clear acrylic sheet and rub it with a scotchbrite pad (steel wool would also work.)
Now comes the tedious part- there are 20 arms that need to be cut out, bent and then placed around a central ring to form the lower spider frame. The dimensions on this are not critical, but you have to constantly check the fit so that it will fit into your previously constructed backplate assembly. You also have to make sure that the clear ring will fit into the slots cut into the spider arms.
The distance from the outer edge to the opening of where the large notch is approximately .08 inches. The trick is that you will have to adjust the fit of this to your acrylic ring as well as the outer ring. You want the spider to essentially press fit snug into the outer ring. Then fit the acrylic ring to the spider. I can guarantee that you will probably have to do some trimming because the spider is so difficult/frustrating to make so that everything is aligned properly. I had to trim probably every opening to get everything to fit properly.
The easiest way to trim the opening in the spider is to use a small sanding disk with a Dremel tool to carefully trim the opening to fit the acrylic ring. The acrylic ring doesn't have to be a perfect fit as it's held in place by the copper wire wrapped around it.
I cut both the central ring and spider arms from 22 ga sheet steel using sheet metal shears and a jeweler's saw. A dremel tool would also work and will come in handy cleaning up all the rough edges. The finished arms were then welded to the central ring. Then the center bottom ring was cut from steel sheet and welded to the spider frame assembly- note how it is positioned. I was short on time so I left out the additional slots. The bolt holes were threaded for 3mm bolts.
As a substitute for sheet steel you could make the parts from brass or copper sheet and then solder the arms to the central ring and then solder the central bottom ring to the spider frame assembly.The parts could also be made from thin plastic sheet as well and just glued together, but they wouldn't be as durable.
Now you have to make 10 little brass tab thingies. These sit on top of the clear ring after it has been placed into the spider frame assembly and then they are then wrapped with 22ga copper wire. Make sure when you wrap the wire it doesn't stick out too far outside the spider frame arms- make sure to check the fit with the backplate assembly- mine is just a light friction fit. The brass tab thingies should be about the same width as your clear ring and the four little tabs should just stick out over the edges of the spider arms. The last bit is to solder some short 24ga copper wires to the tabs.
First cut the inner ring from clear acrylic sheet and rub it with a scotchbrite pad (steel wool would also work.)
Now comes the tedious part- there are 20 arms that need to be cut out, bent and then placed around a central ring to form the lower spider frame. The dimensions on this are not critical, but you have to constantly check the fit so that it will fit into your previously constructed backplate assembly. You also have to make sure that the clear ring will fit into the slots cut into the spider arms.
The distance from the outer edge to the opening of where the large notch is approximately .08 inches. The trick is that you will have to adjust the fit of this to your acrylic ring as well as the outer ring. You want the spider to essentially press fit snug into the outer ring. Then fit the acrylic ring to the spider. I can guarantee that you will probably have to do some trimming because the spider is so difficult/frustrating to make so that everything is aligned properly. I had to trim probably every opening to get everything to fit properly.
The easiest way to trim the opening in the spider is to use a small sanding disk with a Dremel tool to carefully trim the opening to fit the acrylic ring. The acrylic ring doesn't have to be a perfect fit as it's held in place by the copper wire wrapped around it.
I cut both the central ring and spider arms from 22 ga sheet steel using sheet metal shears and a jeweler's saw. A dremel tool would also work and will come in handy cleaning up all the rough edges. The finished arms were then welded to the central ring. Then the center bottom ring was cut from steel sheet and welded to the spider frame assembly- note how it is positioned. I was short on time so I left out the additional slots. The bolt holes were threaded for 3mm bolts.
As a substitute for sheet steel you could make the parts from brass or copper sheet and then solder the arms to the central ring and then solder the central bottom ring to the spider frame assembly.The parts could also be made from thin plastic sheet as well and just glued together, but they wouldn't be as durable.
Now you have to make 10 little brass tab thingies. These sit on top of the clear ring after it has been placed into the spider frame assembly and then they are then wrapped with 22ga copper wire. Make sure when you wrap the wire it doesn't stick out too far outside the spider frame arms- make sure to check the fit with the backplate assembly- mine is just a light friction fit. The brass tab thingies should be about the same width as your clear ring and the four little tabs should just stick out over the edges of the spider arms. The last bit is to solder some short 24ga copper wires to the tabs.
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Thanks, Seth
You could probably even join the metal pieces using JB weld epoxy.
also may i suggest something for the outer ring ?
in my variation of the arc reactor i am building i am using a material for the outer light ring called light pipe
http://www.sparkfun.com/search/results?term=light+pipe&what=products
you may want to look into said products they are very applicable to projects like these!
Another option I just thought of is to cut the parts from double sided blank copper PCB sheet and then you could use a soldering iron and electrical solder to join it. Cutting it wouldn't be fun but it would definitely work and wouldn't require special welding/brazing equipment.
I've seen the light pipe at Sparkfun (they are about 15 minutes from me) but never thought of using it in this application- that's a great idea!
and yeah light pipe is really neat. i just got a order in from sparkfun for my own arc reactor. i cant get over how good it looks ( i'm replacing your acrylic outer ring with two 6mm light pipes stacked on top of each other)
That exactly how I envisioned using the light pipe too- make sure to post some pics! Are you lighting it from underneath or through the end?
and what do you mean by roughing up the areas?
Here's my issue, im following your digrams and sketching them out to make a stencil so i can cut the individual spider arms. the snag im running into, is that the measurements you gave, im following them exactly, but the entire length (1.16) seems to be short, and my spider arms seem to look stubby. where am i going wrong?
Don't get discouraged- just hang in there, be patient and it'll all work out. Remember that none of these dimensions are super critical. What matters the most is how the pieces line up and fit together. If you need help just let me know and I'll help out as best as I can.
Where can i get the plastic cycle thingie? Or how to make one?
Hope you understood what i wanted to say (my keyboard isn't working properly)
this platic cycle thingie