Re: [TCML] Caps

[jhowson4@xxxxxxxxxxx]

Sure, I will go step by step so beginners to capaciter making can follow closely  

 So far I have made 4 caps only one of which is under oil. 3 are rated for 50 kv at .005uf and the oil filled one is rated .009uf at 50kv.  
To make the oil filled one I used 12 inch aluminium foil, 6 mill polyethylene,  .5 inch pvc pipe, lots of electrical tape,  4 inch Pvc pipe, double sided sticky tape.aluminium flashing, 2 bolts 3 inches long, 6 nuts, lots of 5 min epoxy, 12 nails, some .25 inch thick plexyglass,  silicone glue, and mineral oil.
wow i did not realize that i used so much stuff.

first as always I do some math

then I take a big sheet of poly and lay it over the work space so limit the amount of dust that gets stuck to the poly from the work space.(in my case the living room floor because it is a nice and long room)

using the determined plate area I cut the poly so that I have 3 inch magrins on either side of the foil strip.  as well as a 6 inch margin on the front and back of the foil strip.(this is why i like the nice long floor)

I think that the last cap I made needed 14 strips of 6 mill per layer.

next I use the double sided sticky tape along ONE end to connect the 14 poly strips together.

then I tape the foil on (cut to size) with the margins set.

next I stack the 2 layers and tape the .5 inch Pvc pipe to on end.

then cut the aluminum flashing into lots of strips .5 inch by 12 inch. and drill a hole that will fit your bolt into the same place of one end. make lots of them. more than you need necause you don't was to be in the middle of rolling the thing and run out.

I tightly roll the cap (important part next) placing an Al strip on each plate at opposite ends every turn.(you should end up with all your Al strips for each plate on top of each other with the holes all lined up on opposite ends.)  When finished have some one check with an ohm meter to be sure you did not mess up.  it is easyest to fix it now.

while holding it tightly (get some one to help you) wrap a bunch of tight electrical tape around the thing. then you dont need to hold it tight you can continue to wrap the thing untill there is a good layer of tape on their.  you could also add some zip ties when you are done but i found them to be a nusance and the tape worked better.

I then make plexy glass disks with holes for the bolts that fit into the inside of the 4 inch pvc pipe.

bolt the bolts to the Al strips. Then bend the strips so they are facing outward.  

the 4 inch PVC should be long enough to fit the cap and all but an inch of the bolt on either end.
one plexy glass disk is then bolted to the capaciter and the Al strips. (the plexy glass should not be right at the end of the pipe put it closer to the cap rather than closer to the end of the pipe.) you want about an inch and then some between the plexy and the end of the pipe.

use the silicone glue to roughly seal the plexy to the bolt and to the PVC inner wall.

next drill 6 holes in the 4 inch PVC pipe half way between the end and the plexy glass.( the holes should be large enough to fit the nails and still be snug( I used 1.5 inch really thin nails.)) Make sure that the nails don't contact the bolt.

fill the remaining end of the pipe with epoxy (be sure to leave enough of the bolt to make connections.)
the nails hold the epoxy into the pipe (this helps keep the epoxy pipe connection tight an prevent the oil from leaking out.

once that is dry (a few days) smear some more silicon glue on the seams of the end cap  flip the pipe and fill with mineral oil ( if it leaks just dump it out clean it off and put on more glue)

Let it sit for a few weeks and viberate it perodially ( if you put it on something that viberates that is great)  this is to try and get all the air out of in between the plates and layers.
you will have to add more oil at some point.

the next part is a pain in the butt!!

now you have to get the last plexy glass plate right up against the oil with out causing it to get on to the top of it.  and seal it up with silicon glue. (some air is ok as long it it not in between the plates)

then seal this end the same way you sealed the other end. 

and yay you have a nice oil filled cap. That hopefully wont leak



The coil that I made this cap for uses a 12kv 60 ma power supply 
and it is never run for more than 15 seconds at a time with 30 seconds in between runs for cooling

I dont think that this type of cap would be good for a huge high powered ,  high duty cycle coil due to the fact that the oil will proabably get hot expand and explode the cap.

I have used the coil a bunch of times with no problems transporting it or running it.  in fact I am giving it to my high school physics teacher tomorrow.  I will snap a few pics then and post a link tomorrow before it leaves. I will also get a few pics of the caps that are not under oil. which I have never had a problem with either.

Thank You to whoever read the entire post I know it was a long one.

if any one has any questions,comments, suggestions, or even a better idea of how to do something 
I would love to hear from everyone.
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla