Rocket Firing RC Submarine

[redboat219]

Found this on Youtube

http://www.youtube.com/watch?v=Ky2Ra02pyPk

[feet wet]

Nice video. It shows precisely

Nice video. It shows precisely why rockets should not be fired from boats. That could have ended in tragedy despite the apparent precautions.
Jonathan

[mylo]

I must have missed something.

I must have missed something. The only dangerous thing I saw was that boat ripping around at the end. Now THAT sucker getting out of control on you could be a show.

.....I was waiting for that sub to explode while the operator was handling it, blow the guy's hand off, maybe send epoxy shrapnel into the crowd. That rocket going sideways....well....that was just a bit of a glitch in the guidance system. Minor.

I personally wouldn't be launching ordnance from an r/c sub at a boat show though.....too many pesky kids to be potential targets. Take one kid's head off and everybody get soooo wound up.

Mylo

[mike dory]

Rocket firing Subs.

Guy's This is a little telling stories out of school But what the hey. In 1982, Dave Manley & I were shooting Estes rockets out of a 1/48 scale model of the U.S.S. George Washington which I had built. The sub was sitting on the bottom of my back yard pool about 8 ft. down. Now at that time, I was detailed as the on call traffic accident investigation officer for the County of San Diego City of Poway, all this ment was that I had a Sheriff patrol car sitting in my drive way. Well Dave and I shot off this rocket and upon leaving the surface of the water, the rocket turn over about 45 degrees,hitting my patio awning. Then it ricochets off the awning goes through my 70 year old neighbors screen window and ends up racing around on her frontroom carpet a few times before running out of fuel. I will tell you, it is not easy to go and ask your neighbor for your rocket that just ripped up her screen window and made a big mess on her carpet. particularly when your a Deputy Sheriff. Needles to say I paid to replace her window and have her carpet cleaned The rocket firing model is now on display in a hobby shop in San Diego. Dave Manley grew up on my street and now own's and runs Small World World Models. ( A long time ago) Best Wishes and may you never have to go get your rocket Mike Dory

[KevinMC]

Hi Mike,

Was your rocket properly

Hi Mike,

Was your rocket properly balanced/stabilized, or was is a "scale" (finless) SLBM? I've seen several posts where people talk of model SLBMs going amuck, but so far I've not read one where anyone's made mention of designing in the necessary stability for the task to which it was being put. I'm asking only because I have my own model sized "intercontinental" aspirations and if there are lessons to be learned I'm an eager student.

[mylo]

Mike,

It looks like we

Mike,

It looks like we have something other than subs in common.

I'm also a crash investigator as part of my duties with the Royal Canadian Mounted Police, and much of the time have a marked police car in my driveway. (I'm still not sure if my neighbours know that it's what I do for a living....or if they think the cops are looking for me). I try and be a decent, responsible citizen.....but it's just so difficult sometimes. Given your rocket firing story, I think you know what I mean.

Good story, ......you launched that missile from 8' deep and it took flight , that in itself is pretty cool. Plus, your 70 year old neighbour got to tell an interesting story at her knitting club the following week. Win / win situation.

Mylo

[mike dory]

Kevin - The rocket that

Kevin - The rocket that I used was an Estes alpha plastic rocket. Now I had cet the fins down to about 1/2 there original size. The fins fit into groves in the launch tubes. As long as the rocket stayed under water it went as straight as anyone could have asked for. However, once it broke the surface of the water, the fins were just not enough to keep it on a straight rcourse. I wouldn't recommend shooting Estes rocket out of subs. Stay with Propel or other low pressure gas. the chance of starting a fire is alot less as well as injuring someone. You must understand that here in Southern Calif., fires are a very big deal. Also there are civil litigation attorneys on every street corner just looking for every chance to sue you.

Mylo - There are alot of us who work in Law Enforcement and are menbers of the Sub Committee. Casey Thower is a Deputy Sheriff, Duane Hillier, works traffic with you in R.C.M.P. Langley B.C. Just to mention two that I know of. I retired after 34 years pushing a patrol car, from San Diego County Sheriff Office in Jan. 2001. I look forward to meeting you in person this summer at the regatta. How are you coming R/C'ing your big Type V11?... All my Best.. Mike Dory

[hakkikt]

Kevin,
The thing that is normally

Kevin,
The thing that is normally done to stabilise finless rockets is to make them rotate, mostly by adding small inclined nozzles sunk into the back end or the outside wall of the rocket (e.g. tangential exits from the combustion chamber).
Might be a problem preventing the tangential nozzles from firing before the rocket has left the tube. On the other hand, the tube needs to be fireproof anyway.

[mylo]

Mike,

Wasn't sure if the

Mike,

Wasn't sure if the letters R.C.M.P would make sense to you. Here in Canada, they are fairly well known. I guess you can add one more to your list. 34 years in......you did your time, congrats on having your mental stability in check, or at least, fooling us into thinking so.

I've been very busy working on all the internals for the r/c conversion of my VIIc/41 while I wait on a 10 gal. order of West System Epoxy to get going on some hulls. (not sure what's taking so long, it's been a month and they've already got my $1200). The bulk heads, and as per our previous discussion, the trim tank design, have consumed the most part of my time. I've completed my design as well as the masters, and am in the process of making molds to cast the parts. Work is progressing slowly, mainly due to the added R & D (another name for trying stuff out, discovering it won't work, throwing it in the garbage, starting over), but I am happy with how it's coming together. I do believe it's going to be a very nice functioning sub. The bulk heads fit very nicely where they should, which was no easy engineering task in itself.

I'm inching along with the project. I'll very likely be posting more questions of "how to do", keep your eyes peeled, I can use the help, which is greatly appreciated. My work on the r/c conversion of this sub could have been another complete thread. This phase has not disappointed me, everything is taking longer than I thought.

Mylo

[redboat219]

Some new video
http://www.youtube.com/watch?v=yYlgnIkKkl4

Some new video

http://www.youtube.com/watch?v=yYlgnIkKkl4

[KevinMC]

Mike- Points well taken, and

Mike- Points well taken, and thanks for the details on how you did it. Was the Alpha body full length, or did that get cut down too? (Alpha's are nearly a foot long aren't they?) From the research I've done so far I understand that breaking the water/air interface cleanly is always a challenge, even if stable flight afterwards is expected.

Hakkikt- Most SLBMs rely on a gimballed rocket motor for stability thus they get away from the need for fins, but this is really only practical for liquid fuelled rockets. Without gimballing, some form of "classic" stabilization is definitely required. While spin-stabilization is possible, it's only effective if the rocket is spun-up enough while still in the guiding tube to ensure that it continues straight after it clears the launch tube. (And after that point the all energy spent on "spin" is just wasted.)

[Rick Teskey]

RCMP

Thats Raw Carrots and Mashed Potatoes right?
LOL (with respect )
Rick

[hakkikt]

Kevin,
I was talking small-scale rockets

Kevin,
I was talking small-scale rockets - for example there was some kind of exotic handgun that fired small spin-stabilised rocket projectiles.
Yes, thrust vectoring is the way to go with big rockets: gimballed nozzles or engines, exhaust vanes (like the V2 had) or sometimes asymmetric injection of gas into the nozzle. Just no way to fit such stuff into into a normal-sized model rocket. : )

Personally, I will keep my hands away from rocketry in modelling, too much fire next to stuff that is too flammable. Working torps one day perhaps, but nothing that burns.

-Harald

[mike dory]

Model rockets & Subs

Kevin - I cut down the length by removing almost all the paper body. I thought that if I cut the length, I could also cut the fins down. As I said it worked well under water. However, once it hit the air it was a differnt story I have to go along with others who have posted here. It's not a good Idea to mix buring rocket engines and Subs. There is just to much to risk. I'd never try it again. Not to mention being very embarassing. Best Wishes Mike Dory

[mylo]

Has anyone ever attempted a

Has anyone ever attempted a compressed air propulsion system for a sub rocket launch ? Even if the launching event was much less spectacular, and the range of the rocket limited (which would make it easier to retrieve), it might still be a cool effect to have launched a rocket from a sub without having to use burning fuels.

I just know that if I had a nuke boat, it would HAVE to launch rockets of some sort.

Mylo