Ramjet Sabot

ferret_guy · Mon Dec 17, 2012 5:53 pm

FYI for all the barrel is going to have to be something like 8-10m long (26-32 ft) long for the acceleration i was talking about with close to liner progression until then (it has decreasing returns after that)

PaperNinja · Mon Dec 17, 2012 6:46 pm

The barrel will be able to be split in multiple sections right? It has to be anyway because of the different stages?

Anyway, I'm figuring out exactly how my capacitor bank will be set up for the injector, I'll post when I've decided.

ferret_guy · Mon Dec 17, 2012 8:17 pm

yes you could split it up

PaperNinja · Fri Dec 21, 2012 3:03 pm

If the projectile can be about .7 inches diameter, than it could fit inside a 12ga shotgun as an injector. I think that might work, provided the shotgun can fire it fast enough to start acceleration (it should be able to unless the projectile is really dense or long). I kinda gave up on ETGs, this plan is much simpler I should have listened to you guys from the beginning

fyi, this is legal where I live

mobile chernobyl · Mon Jan 28, 2013 11:47 am

How's this project coming along for you?

PaperNinja · Mon Jan 28, 2013 1:13 pm

I had to drop the project... My parents had funded my earlier projects because it was educational, but i did some math and this project was going to be way too expensive for them to take lightly, and they thought that the design was too simple for me to learn anything and they were unwiling to fund it. My mom was getting sick of the guns anyway. I will have a 6000 psi rated hybrid soon though, it's all assembled and ready, I'm waiting on the barrel, spark plug, and pellets in the mail (and have been for a long time

)

My new project is actually not spud related, I'm getting into robotics/multirotors. We had an ar drone that we're upgrading with a px4 board, and we got a 3dr hexacopter for anyone that's also interested in multirotors. The hexacopter runs on Arduino so I'll have to learn to program that, but I already know java and python pretty well so that shouldn't be too much of an issue.

ferret_guy · Tue Feb 12, 2013 11:08 am

Thats a shame. I may have a new summer obsession now...

PaperNinja · Tue Feb 12, 2013 11:33 am

I know! I still think it's a cool idea and a good project, though it might be a more long term project than I was expecting.

Btw, I found this page: http://www.engineersedge.com/pipe_bust_calc.htm
helpful. When I looked at the option on mcmaster, I found that enough pipe to make the tube would cost very close to $1000 (IIRC). That's not too too much, but it doesn't include all the other stuff and shipping. Also, the materiel I was looking at was just rods of metal. All the high pressure pipe I've found is extremely small, and I think it was gonna be bore .7", so I'd have to get it drilled through which wouldn't be cheap

Just1ofgod · Tue Feb 12, 2013 4:38 pm

Just a thought IF you are in the us there are off the shelf rocket engines you could use that would be alot cheaper than what your thinking of i just dont know about the pressure but they are capable of propeling a small rocket through the speed of sound as it is as a 2nd stage could be impressive

http://www.apogeerockets.com/Rocket_Mot ... or_G79W-10

PaperNinja · Tue Feb 12, 2013 5:38 pm

Model rocket engines are not really what I'm interested in