Tesla Coil Build Thread

[Sigurthr]

Looks good, I don't see any errors in wiring! That's the same wire I use btw.

Heh you can tell the caps apart, my old ones are all UV discolored, XD.

Now read up on how to properly set your gap width, it's in this thread a ways back. If ya can't find it let me know.

 

[Speedy78]

I believe it was fire the nst without the mmc connected until it will no longer fire anymore and then shrink it down slightly.

 

[Sigurthr]

Yep. You have to make sure it fires on EVERY power up when you have it where you think it is set.

Going to fire it tonight or wait till normal hours to scare the neighborhood? Lol.

 

[Speedy78]

Still need to hook the secondary up to the top load and to ground and ground the strike ring. Oh and make an rf ground in the backyard. This weekend I'm guessing.

 

[Seoul_lasers]

BGS update.

Got a lesson in series vs. parallel circuits today. Tried to run 3 fans in series and there was enough voltage to spin any of them. Ooops.

Two wires in the back, left wire goes to the nearest NST terminal, right one goes to my tap wire. Two wires up front, the one that crosses in front of the fan goes to the second NST terminal, the second goes to the bottom of the MMC.

Firstly excellent looking coil! Nice clean setup!! +1 :drool:

Some things I see that you might want to think about.
1) Wire insulation. Overtop of wires especially ones going from the MMC to the Static spark gap need to have PE wine tubing sleeved overtop of them.
The thin insulation can breakdown rather quickly under exposure to ozone and the high potential you're running.

2) Short thick connections are best in the primary circuit!!!
The Wire length you've got looks fine, but you'll get much better output by using the cable from a battery jump starter kit and sleeving that with large dia wine tubing. Actually I think you'll need 2 kits for this.

* The wire to the Primary circuit from the NST can be 12ga -14ga wire as it's carrying a very small current... however I highly recommend sleeving that too.

The momentary discharge current on an MMC like yours is probably somewhere around 500A or so. Thin wire will not allow the full current to pass properly.

Other things I recommend.

- Already mentioned by other members, is to move your transformer(s) out of
the path of the RF and run it externally. This will allow your transformer to have a longer life.

**Use a wide copper strip as your main RF ground connection. This really will improve performance. The better the ground the better performance you'll see.
Use a dedicated RF ground and not your house wiring!!
You probably already are doing this anyways so it might sound redundant. Sorry.

* though there not much you can do with your primary winding as it is now, I'd have opted for a flat primary so that there is less likelihood of the Sec to primary arc/strike. These strikes are often fatal to the XMFR unit and MMCs.

You'll need to make sure you've got a decent strike rail


With those fairly simple tweaks in mind you can boost your performance
a fair margin. Longer more consistent sparks.


I'll rep + you once the system allows me to!

Good work!!

 

[Speedy78]

I can change the wire going to the mac and primary. I have 8 Guage amp hook up wire for a car stereo. Is that better? What is meant by move the transformer out of the rf? Strike rail is already in place. Just needs to be hooked up to the ground I'm current making. How should I run the ground to my ground point. Wire?

 

[Seoul_lasers]

I can change the wire going to the mac and primary. I have 8 Guage amp hook up wire for a car stereo. Is that better? What is meant by move the transformer out of the rf? Strike rail is already in place. Just needs to be hooked up to the ground I'm current making. How should I run the ground to my ground point. Wire?

The 8ga wire will most certainly be better! Make sure to
Sleeve it with large dia wine tubing for added protection.

As for the the xmfr, move the NST away from the coil.
Currently your xmfr is at the base which may shorten it's life.
Run it 10-15ft away from the coil with a OoO safety gap.

The main ground wire to RF ground should be
the copper ribbon. This will guarantee a soild connection to RF
Ground.
Hopefully this helps explain your questions.

 

[Speedy78]

Thing is i don't have the room to store the equipment all over the place and run it like that. It should outlast the short runs i will most likely have on it anyways.

Have a link for this specific wine tubing you speak of at a cheap price?

Also because it will be moved and for money reasons I can't run and then stow and then run and then stow copper plus 10 feet or so of it will add further to the price tag. What's my next best option? Would like to add a plug to the back of some sort so the ground wire can be unplugged.

 

[Seoul_lasers]

Thing is i don't have the room to store the equipment all over the place and run it like that. It should outlast the short runs i will most likely have on it anyways.

Have a link for this specific wine tubing you speak of at a cheap price?

Also because it will be moved and for money reasons I can't run and then stow and then run and then stow copper plus 10 feet or so of it will add further to the price tag. What's my next best option? Would like to add a plug to the back of some sort so the ground wire can be unplugged.

Do you have a plastics store or a wine making store in your area? That's where I'd get it from.
In Victoria BC, I get my tubing at a decent price from Industrial Plastics and Paint.

 

[Speedy78]

Is it just the clear tubing? I can get that at the local government and ware store. I'd it a specific material I'm looking for?

 

[Seoul_lasers]

Is it just the clear tubing? I can get that at the local government and ware store. I'd it a specific material I'm looking for?

correct. Clear is the best. It's made of PE which has an extremely high puncture voltage. Sometimes it can also be made of PVC... thats fine too.

 

[Speedy78]

So i put it on the wire going to the spark gap as close as possible to the connection and the from the mmc to the inner most turn. How should i route it over the way my mmc is set up? Also does it need to be on my tap wire?

 

[Sigurthr]

The plastic tubing is a good call worth investing into.

I disagree with the need to move the NST offsite though; simply using cheap steel chickenwire tied to central RF ground to form a faraday cage around the NST has always worked well for me. The longer your NST leads are the more HF they will pick up. You don't really gain anything by moving it off site unless you use HV Coax as transmission line for the NST output.

In all honesty though I don't think even that is needed. I've yet to see a NST fail from a Single-Fixed-Gap parallel spark gap letting RF into the NST. It is different with RSGs as there is no automatic firing without the electrodes being lined up, so you MUST use a safety gap, but for a fixed gap with adequate quenching/cooling it just simply isn't needed. Multi-gap SGs can also fail open like a RSG can so you -should- have a safety gap, but with single fixed gaps your main gap IS a safety gap and is by definition set to fire SOONER than a safety gap would.

Edit: Btw copper strapping for RF ground lead is ideal but very expensive. You can use up to 12ga extension cord with all three conductors shorted at both ends as a damn good RF ground lead as it forms a very poor man's LITZ wire. Another exceptionally good ground lead is using HF amateur radio grade RF coax line as it is designed to take up to 1500Watts at 50Ohms with low loss.

 

[Speedy78]

How do you weigh in on the current primary side wire diameter being 10ga solid copper? Parents are in town for a few days and I would like to do some quick runs for them.

Also I want to use an extension cable hooked to the grounding point and all three terminals wired together and plugged into an outlet like my nst switch is. And then the secondary and strike rail hooked to that. Would that work fine?

 

[Sigurthr]

How do you weigh in on the current primary side wire diameter being 10ga solid copper? Parents are in town for a few days and I would like to do some quick runs for them.

10Ga will work fine. The thicker the conductor and flatter the conductor the better, but you have to weigh in the cost and complexity versus the incremental increase in output, if it is worth it is totally up to you. To me it wasn't worth it. Going to thinner than 10ga is a no-no though.

Also I want to use an extension cable hooked to the grounding point and all three terminals wired together and plugged into an outlet like my nst switch is. And then the secondary and strike rail hooked to that. Would that work fine?

That works perfectly. Just don't use a 14/3 (14ga) extension cord. Gotta be 12 or thicker. OR you could use a junction/outlet box as your grounding point and run as many (4 would be easiest) extension cords in parallel as your ground cable. Use an identical box(es) as ground rod receptacle connection point and then the cable(s) are easily removed and stored! That's what I would do (4 outlet box & 4 preferably 12ga extension cords).

 

[Speedy78]

I have a 10/3 for my shop cord. Can I just use that by itself and the outlet on the coil and the outlet connected to the ground point be shorted? It is like 25' long though is that too much?