Gor

Go read through 'Battle field effects'

Whats the point in asking for comments if all you do is snub them coz you cant take criticism?

Hey, have you guys got past his first page and looked at some of the stuff he has built? Apart from his glib way of talking, what I see is that he has taken care over what he does and put some craftsmanship into what he has built. Maybe I am thick but I learned a lot from his site.

And no I havent got my coil fired up yet. Finding a power supply is proving near impossible. I also want to get to know the world of ultra high voltage applications a bit better as it is clear that there is a lot of fun to be had here if you don't kill yourself first. (bit like pyro).

I agree his ego is bigger than the planet but i didn't realise his science was dodgey.

You know how to do the maths on HT induction circuits?

I appreciate that this is well off Pyro...but it does get pretty hot

Dissolve them in water, as concentrated as you can, then mix into the ehtanol max 20%. Boric acid doesnt dissolve so well. Copper Nitrate goives a good blue green and dissolves well.

I've got every colour including mauve, purple and orange, except pure blue. Tips of flames are often yellow which can be nice

ALso depends on whether you are burning pure ethanol or whether you use a wick. If you use a wick then you can sometimes just finely powder the salts and rub them in.

Don't use a carbon based wick. I sometimes use wire wool, or ceramic fiber.

I will eventually post some pictures (took some good nes at new year), but I'm snowed under with work

At the risk of being pedantic, air resistance is pretty insignificant when dealing with this sort of mass. It affects a feather because the weight to surface area ratio is so high. (There is also some sense in streamlining a bullet as its velocity is so high, but I doubt if it is worth putting a point on a shell). Robert is right, the inertia is the shells resistance to the pressure generated in the tube.

Also be aware that testing an overweighted shell is pretty useless if your real shell is going to be larger and be fired from a larger tube. The thrust of the charge is generated from the rapid production of gasses and will reduce by the square of the radius of the tube. i.e. 10g BP on a 1" tube will give 4x the thrust of the same amount in a 2" tube (roughly, other factors also come into play). So in crude terms, a 100g shell 2" in diameter will need a different lift from a 1" shell of the same weight to reach the same height.

I hope nobody is looking up when the sand comes down!