On my 6" coil, I have a small 9" x 1.5" toroid to protect the windings. Then I use either 1 or 2 large OD dryerduct 6" toroids spaced above that on a threaded rod. With anywhere between 1-3 inches separating the closest surfaces of the toroids. Sort of like how one of those ring segment toroids are spaced.
I'm running 6kw and get nice sparks without a breakout. But I prefer to use a breakout for the purpose of gathering all the little arcs into one larger one, makes it less chaotic.
Check out the end of Nigel John Stanford's cymatics Video for a good representation of how I generally set mine up.
Only mod I want to make to my coil at the moment is change the 10 turn primary into a 2 layers of 5 turns version, allowing me to reduce the diameter of the strike rail and keep the arcs out of that area.
Cheers,
Sent from a tiny phone with a tiny keyboard.
----- Reply message -----
From: "John Cooper" <wt5y@xxxxxxxxx>
To: <futuret@xxxxxxx>, <tesla@xxxxxxxxxx>
Subject: [TCML] New nst/primary strikes
Date: Tue, Dec 23, 2014 7:54 PM
Yeah at first when I tried a 6" dryer duct I wouldnt get any sparks without a breakout point. I'm getting them now though. After adding the nst my sweet spot is now roughly 3 turns in on my primary coil. I also doubled my mmc by adding 16 caps in parrallel with the original 16.
On the toroid I actually had them squashed together. Everyone I've seen on various sites I've never noticed any gaps when using double toroids. I have 6ft of 1/4 20 allthread so I can try that. Is it always better to have the smaller topload on bottom? I know if I raise them too high I will get small breakouts from the top windings on secondary.
Thanks for all the feedback.
John cooper
Sent from my Cricket smartphone
-------- Original message --------
From: Futuret via Tesla <tesla@xxxxxxxxxx>
Date: 12/23/2014 15:13 (GMT-06:00)
To: tesla@xxxxxxxxxx
Subject: Re: [TCML] New nst/primary strikes
I agree that eliminating the strike rail would likely help. I don't
use them. Also
the upper toroid can probably be raised even higher above
the lower toroid. I'm assuming you have about 1" between
the two toroids. You could raise the upper toroid and have
maybe 2 or 3" between the toroids and see how that behaves.
And yes a larger diameter toroid will tend to push the sparks
out somewhat farther. You'd have to retune of course. Also
there's a limit to how large the toroid can be and still get
good looking spark action using a given input power.
It's usually good when the max. spark length is about 3 or
4 times the toroid diameter, at least from a spark appearance
point of view.
John
-----Original Message-----
From: Jon Danniken <danniken@xxxxxxxxxxx>
To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
Sent: Tue, Dec 23, 2014 3:52 pm
Subject: Re: [TCML] New nst/primary strikes
On 12/22/2014 08:50 PM, John Cooper wrote:
> Have two nst's for12kv 60ma total now. Longer streamers now. Too
> long sometimes they blow by the strike rail to the primary. Its 21"
> from bottom of topload to primary copper tubing. The strike rail sits
> 3.5" above primary. I tried putting my smaller 3"x15" toroid under
> the 4"x17" to raise but still hitting primary. A breakout rod point
> up helps a lot but every now and then it hits bottom. I'm
> considering doing the 6" secondary which would add another 15" in
> height above primary but until then Is there anything other than
> breakout points that would help. Would changing the diameters of the
> toroid help? Ie using different size pie pans with dryer duct. My
> thinking is if it was wider then the primary coil would not be right
> under.
>
>
> My secondary windings start flush with the primary, if I raise it the
> coupling will become weaker meaning shorter streamers?
>
>
> I've seen some coils on youtube and the streamers go down but outside
> the primary, wondering if my strike rail was removed would that stop
> it from attracting it to the primary?
Yes, I believe it was Terry Fritz who modelled the strike rail, and
found that it was an attractor for streamers. I ditched mine and found
that it drastically reduced primary strikes.
If you are already getting primary strikes, it won't hurt to experiment
by removing the strike rail.
Jon
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