do the regs cover coil guns

Hmmm.... there aren't any goveernment regulations that cover such a thing as far as I know... similar things (as far as recovery) have been done with boosted-darts: there was a writeup on ROL that I saw a while back... the unpowered "upper stage" was a PML "Cirrus Dart" with an extra nosecone (modified to engage alignment features on the booster) on the rear; recovery used electric ejection by way of a conventional HPR altimeter. (I forget whether dual deployment was used.)

The coilgun idea sounds interesting... acceleration forces might be abit extreme to achieve practical rocket performance, though...

-dave w

Not NAR Not AMA I guess not NRA

It may be an unaffiliated hobby.

Hobby electronics/electrics?

Jerry

Hobby electromagnetic ballistics?

Does 'rocket' not entail the propulsion device being contained within the vehicle? I can't see having the coil and supply on the rocket being a good idea (too heavy).

This is an argument against gravity wells, not mass drivers.

Also read the book "The Moon is a Harsh Mistress". They use gravity well weapons there too.

"How are we going to fight?" "We're going to throw rocks." "No, seriously." "Yes, seriously."

It's on topic too. They launch ore-filled rockets at earth, and purposely lawn dart them from orbit. Terminal velocity impact at that speed resembles a nuke blast, but without the nasty radiation.

It's not a rocket, it's more like a catapult... an electrical one instead of a mechanical one.

-dave w

Not aluminum rings. Iron or similar alloy. Must be susceptible to magnetic pull/push, which aluminum is not. Heavier metals... ferrous metals, I believe.

With current technology, the weight involved and the energy requirements would make it extremely impractical; you'd need an 18 wheeler to haul the launch equipment large enough to launch anything larger than 6 inches tall.

The videos on the site show a device that is 4 or more times heavier, but not much more powerful than, a B-B gun. I am sure others have come up with more compact and powerful variations, though, so I would not rule it out in the not-too-distant future.

~ Duane Phillips.

ROTFLMAO!

Back to the coloring book for you!

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Forget it. If you scale it up enough to be useful, someone will decide it's dangerous or could be used as a weapon. (Weapon: something that if pressed against someone's face and activated, might cause them to be hurt).

Then they'll re-interpret an existing category to cover it ("Uh, it shoots something, so it must be a gun." or "Uh, you could put a needle on the end and inject someone with AIDS with that, so it must be a hypodermic!")

Either way, you won't be allowed to have it, no legislation required.

In theory for a "zero stage" which remains 100% on the ground for a targeted 15% of total rocket power.

Jerry

Aluminum rings *will* be repelled by an alternating magnetic field.

Lenz's Law states: An induced electromagnetic force generates a current that induces a counter magnetic field that opposes the magnetic field generating the current.

So, think of the aluminum ring as a one-turn secondary coil on a transformer. The coil is shorted, so maximum induced current will flow, resulting in maximum magnetic field generated. The induced magnetic field will directly oppose the magnetic field that induced it, and the ring will be repelled.

I did a demonstration of this for a science fair project in grade school, and won 1st prize. I used a short piece (1.5" long, .75" diameter) of aluminum pipe, rather than a ring, to allow me to more easily constrain its motion to one axis. It was a loose sliding fit over the plastic tube that covered the square steel core. The electromagnet was hand-wound from several thousand turns of "bell wire" (bare copper with a varnish coating for insulation), and connected to a 110 VAC line cord, with a momentary contact push button. When the button was pushed, it would throw the aluminum tube about 2 feet straight up in the air off of the 4" long plastic-encased steel core sticking out the top of the electromagnet.

Bottom line: all that was required was that the "ring" conduct electricity. Copper wire loops taped to cardboard tubes worked just fine, as well, but the aluminum tube made for the best "display".

For some reason, I had a knack for winning science fairs in grade school with projects that threw things in the air, blew up, etc. I wonder if I could get away with any of them in today's litigious "zero tolerance" world....

- Rick "Dust Explosion" Dickinson

Eddie currents will be generated in *any* conductive material in the presence of a changing magnetic field. There are plenty of practical examples of this at science 'museums' such as Questacon here in Canberra, Australia.

BTW a rail 'gun' is able to 'fire' a projectile which definitely *would* class it as a firearm in Australia. In the end it is the result that counts, not how you achieve it.

Cheers

Bob Stephenson bstephenatnetspeeddotcomdotau

I was not aware the FF rules on firearms and destructive devices in the gun control act covered metallic content of rockets.

they are a destructive device only if equipped with a warhead thhat I can find in my green book

nope,

better stick to demonstrations of owl preserves and how they effect h*mo sapiens male mating habits.

They don't.

The only regulatory "intersect" I can think of might involve the applicability of the FAA "model rocket" or "large model rocket" categories, which may among other things (IIRC) call for lightweight nonmetallic construction... but then, it's not clear that the device would constitute a "rocket" in the first place, since it is not propelled by expelling gas produced within it.

What _are_ the FAA rules, if any, for unpowered ballistic projectiles? (Do the "pumpkin throwers" apply for waivers or anything?) Legally, an unpowered coilgun-launched dart should be treated comparably!

-dave w

Wouldn't that be rather hard to spread on the toast, with all the feathers and everything?

-dave w

GREAT , we can have those. thank the lord and the second amendment. so if it's a gun, bring em on !

those are handed out free on many streets by good will groups to prevent the spread of aids of all things.

I now really confused.

have you seen anvil launching on Discovery ?

no waivers that I am aware of.