How to build a Tesla Coil

Step 4: Prepare the Bases and Wind the Primary

Align the metal stand in the center of the bottom board and drill holes for bolts to go through. attach the bolts tightly upside down. This will allow you to put a base for the primary on top of it. Then bolt the primary's base in. Take your pipe and wind it into a pretty upside down cone (not the flat spiral in the pictures). Then mount it on the supra-base.

Optional was the addition of 2 supports that I zip-tied the primary to.

Forgot to add how to make the spark gap! It is just two bolts in a open-air wooden box, and they are adjustable for tuning, etc. See the last image...

Comments

[dgraham2]

I really wish to understand the way the base is set up. I look at a picture and I think I got it but then I see another and it contradicts my previous thoughts about it. Is the metal screw facing up on the sub base and the screw thing (with PVC inside) screwed into the metal? I thought this but it just doesn't look like it in the photos. Also, I'm not understanding how to wire the capacitors. Thank you so much for this tutorial.

[disappearingshadow]

I was wondering if I could please have a copy of the PDF file please. I'm gonna make this for my high school engineering class :)

[DevCoder]

File -> print

[Tophernator309]

How do you make the top part. Can you plz comment to this one. I need it before March.

[Tophernator309]

Wow, someone should really help him.

[genious123]

What should be the distance between each winding on the primary coils????

[smacdonald5]

I was wondering where you bought the wire from????

[createthefuture]

can you explain more of what you did to build your discharge terminal. and also more about the spark gap. what does glen781 mean about the 6 Snapple bottles with a 15kV 30mA NST can be deadly! If you are using a NST .could you add more images of the tesla coil close up and whats under the base and how thing are framed. thank you

plese respond at [e-mail]

[pdiffley]

Does anyone roughly know the voltage rating or capacitance of your average snapple salt water capacitor? Im trying to figure out how many ill need.

[takide]

goto this site to calculate the capacitance:
hyperphysics.phy-astr.gsu [DOT] edu/hbase/electric/pplate.html#c1
i think the capacitance is about 4uf (which is a ton for 15kv!)

[Crtek]

what did you connect the primary to?

[aweis]

the primary coil is only attached to the circut, the secondary coil is powered by induction, of magnetism of electricity flowing through the primary.

[sarosh6]

 How is the PVC pipe attached to the base? 

[DevCoder]

the floor flange and pvc pipe screw
you also don't need to pm me because i see all the messages posted on my instructables

[extrordinary1]

I built my first one back in 93.  My secondary was a 3 inch pvc pipe nearly 3 ft long.  My capacitors were salt water also, but gallon jar sized.  I extended my terminal capacitor with a pipe another 3 ft up so it was slightly tunable.

My second one, was a giant!  I had a bunch of hard cardboard rings from steel banding rolls.  I used a sandable primer and made them smooth, then painted them flat black, and coated them with triple thick spray plastic.  They were 18 inches dia.  I built a 1x2 frame for the rings, having 8 vertical stands.  I wrapped each of these rings for my secondary coils using recycled TV and computer magnet wire from the tubes.  A lot of extra work, but it was after all, free wire.  Leaving 4 inch gaps between rings, this monster stood 10 ft tall.  I had 6 30 gal. salt water capacitors feeding the primary.  I used two very large salad bowls to make my terminal capacitor top.  I had a friend spot weld the bowls together.  We had drilled a hole for the large bolt in the bottom of the bowel and set it inside the stainless steel pipe extending above the stand.

It is amazing how bright halogen lights get from the feedback into the powerlines outside.  Wasn't intentional btw.  Just happened.  HV diodes were used to prevent this later.
Fired it up Halloween night in the front yard.  Nobody came to the door, lol.
After it had been running over an hour, the FCC paid me a visit.  It was jamming particular freqs. and I had to shut it down.  It had a very wide bandwith.

I would love to play with such things again, but I have a pacemaker/defibrillator now.  Can't play anymore.  All I can do now is admire others work, from a safe distance, or photos.  For what it is worth, it is a cheap way to turn your lame halogens into high intensity lights using a small coil wired to the halogens.  A 250 kV coil works very well on enhancing the intensity of halogen lights at jobsites.  Make sure the feedback is not blocked so the lights will get very bright.

Nice job.  That is a nice sized coil in the last pic. 

[electridanger]

that is a big one

[zottffssen]

Thanks for the cool and interesting post, but your bold is annoying lol

[sarosh6]

 Do we make a  hole in the upper base, put the pvc pipe+pipe screw through it and then attach it to the flange ?
... because there isnt one in the first pic and the next pics show the pipe attached from the top.

[instructuionsnotprovided]

never mind, smaller right?

[instructuionsnotprovided]

so should one make the primary bigger?

[patches1]

 Other sources state that the spark gap requires a fan. Is a fan really necessary?

[scasteel13]

What type of transformer did you use? Like what is your power source? And you both ends of the copper tubing going through the base, but only show where one connects. Help me out, please!

[Teslaling]

The Primary coil shouldn't be at that steep of an angle.  A primary coil should be between being flat and a 20 degree angle because anymore than that can cause over coupling between the primary and secondary coils.  It gives a reduced performance.

[keir.havel]

What did you use for a transformer, how did you make the toroid and where did you get energy for your capacitors etc.? You need to add much more info

[beastboy409]

Does the pvc through the wood? Do we drill a hole through the wood for the pvc?

Does the pvc get mounted on top of the wood?

Can't tell from pic!

[codex653]

can stranded wire work just as well as the copper tubing for the primary? i don't really want to buy the tubing since i have alot of wire hanging around and i've had success with stranded wire before on some smaller coils but haven't tried it on one this big yet. i know that the tubing is ideal because of the skin effect but i just want to make sure if a bigger coil will work with the stranded wire. also what is the distance between the progressive windings of the primary and the secondary. i see it increases, but by how much per turn?? i've noticed with some of my coils that distance between the primary and secondary matters. thanks!

[DevCoder]

To answer your questions:
- Stranded wire should work, but there's no harm in experimenting
- Well, I just made it an arbitrary shape that didn't get hit my the discharge terminal, but it looks about at a 70 degree angle with the board. The distance and shape matters, but I'm not exactly sure how (again, experiment!)

[codex653]

ok thank you, that's what i was wanting to know. now it's time to go experiment! haha :)

[Turtles never lie!]

I'm having trouble straightening the copper tubing out, do you know an easy way of doing this?

[DevCoder]

spend a long time on it with your hands, but make sure to not put a sharp bend in it. (that sounded nasty) :D

[force9000]

Is the primary wired to the secondary in any way is is it just wraped around it?

[spiral_72]

Instead of the flat spiral in the second picture, make the "upside-down cone" like in the fourth picture. I think you could wind the coil flat like the second picture, then pull it up to height like the fourth. That's what I'm going to try anyways :)

[DevCoder]

That's actually what I did, its a lot easier to make a flat coil and then bend it up.

[lwil]

You state 'Dont do this kind of primary on a coil this small' What kind of primary should be done then?