Is this legal?

Potatoes last one shot, so build reusable! Discuss ammo designs and ideas. Tough to find cannon part or questions? Ask here!
User avatar
VH_man
Staff Sergeant 4
Staff Sergeant 4
Posts: 1827
Joined: Sat Dec 09, 2006 6:00 pm
Location: New Hampshire
Been thanked: 1 time

Thu Dec 27, 2007 8:56 pm

comon you guys!!!!!!! take blowgun dart and fire it straight up........ notice how it remains stable????

how is a blowgun dart different from a rocket? in my eyes, this is actually SAFER than launching from a launch rod. the reason thats there is so that the rocket has time to get moving fast enough for the rocket to gain stability before it takes off.

if anyone has rocksim, you can experiment with launch rod lengths. if you set it at 0, the rocket goes ALL OVER for a few secodns then straightens out when it hits the speed where its fins do something in the forms of stability.
User avatar
BigGrib
Corporal 2
Corporal 2
Posts: 652
Joined: Mon Oct 01, 2007 11:43 pm
Location: TriCities, WA
Contact:

Thu Dec 27, 2007 9:08 pm

TurboSuper wrote:I believe most storebought rockets are designed so that the change in weight from the burning engine doesn't offset the center of gravity to the point where the rocket changes course.

I read a technical manual on model rocketry (put out my Estes), which outlined how to test a rocket for stability (tie a string to the nose cone and swing it around), and to add bits of clay if it needs balancing. I'll assume their premade ones come pre-balanced.

I once just got a really small rocket and put a C6-6 engine inside of it...thing flew into a cloud.
Umm i know that the last model rocket i bought which was about 3 years ago and it came with a little deal of clay to go in the nose cone to balance the deal out.

As far as timing the ignitor to go off after the rocket leaves the barrel, how bout just a little switch that engages on the way out of the barrel like a spring switch or something with all the ignition system, ie a AA battery a micro timer and a switch, housed inside the rocket itself.

I also like the idea of a tiny drogue chute to keep the rocket flying straight, and having it strung right behing the engine so that upon ignition the drogue is released.

the only thing i think might need attention is the stability of the rocket in the barrel, maybe used two sets if fins to keep the rocket centered and then also a sabot for launching the rocket. ok thats all my thought on how to make it work safely
Yea, that's definitely going to get you at least a tazer.
<a href="">DONT TAZE ME BRO.. DONT TAZE ME... AHHHH</a>
facebook.com/biggrib
sandman
Corporal 2
Corporal 2
Posts: 672
Joined: Thu Mar 15, 2007 6:59 pm

Thu Dec 27, 2007 9:21 pm

@ TurboSuper you are correct about the store bought rockets they are designed overstable so that payloads can be added and the center of gravity still be ahead of the center of pressure. But, on the stability you dont tie a string to the nose cone you tie a string around the center of gravity and swing it around your head and add weights till it stops wobbling.

EDIT: OMG, i thought i was like the only person in the world with rocksim, lol, now i know there are others out there
User avatar
VH_man
Staff Sergeant 4
Staff Sergeant 4
Posts: 1827
Joined: Sat Dec 09, 2006 6:00 pm
Location: New Hampshire
Been thanked: 1 time

Thu Dec 27, 2007 9:37 pm

hahaha sandman i LOVE my rocksim........

i screw around with that when im bored with the really big engines and dream................
sandman
Corporal 2
Corporal 2
Posts: 672
Joined: Thu Mar 15, 2007 6:59 pm

Thu Dec 27, 2007 10:12 pm

lol, i <3 rocksim too, but i do wish it could model fins on fins and external engines but ill take what i can get.

it be building whats below now, but i discovered spudding and i dont have the monies for it anymore :(
Attachments
teary eyes
teary eyes
ralphd
Specialist
Specialist
Posts: 192
Joined: Mon Dec 17, 2007 8:07 pm
Location: Niles Ohio

Fri Dec 28, 2007 8:40 am

It's been awhile since I messed with model rockets. I started with Century then Estes. I still have a soft spot for them but it's dead here in NE Ohio. Sure, a few scout troops play with them for their merit badges but not like when I was younger. The string test is important but you must have a launching rod to stabilize the rocket at launch. Believe me, this I know for sure. I used to try to launch different ways and with different payloads...remember the 110 camera.
sandman
Corporal 2
Corporal 2
Posts: 672
Joined: Thu Mar 15, 2007 6:59 pm

Fri Dec 28, 2007 4:13 pm

ralphd wrote:but it's dead here in NE Ohio.
i will never let it die, so its still alive
User avatar
Bubba05
Corporal
Corporal
Posts: 518
Joined: Wed Mar 21, 2007 9:05 am

Wed Jan 02, 2008 12:56 am

Yeah i think thats the bloke? But this one gave a licked a 12 gage.

Bubba
User avatar
Pilgrimman
Specialist 4
Specialist 4
Posts: 480
Joined: Thu Jun 28, 2007 1:10 pm
Location: Grants Pass, OR

Wed Jan 02, 2008 1:07 am

@ Sandman

I've got it too. It's for a physics project. Guess what the body's made of? That's right! PVC! :D
Yeah, we wouldn't want to anger the bees, now would we??

I HATE YOU BEES! I HATE YOU BEES! I HATE YOU BEES!

LMAO Classic!!!! I love Family Guy!
sandman
Corporal 2
Corporal 2
Posts: 672
Joined: Thu Mar 15, 2007 6:59 pm

Wed Jan 02, 2008 10:43 am

woot, more believers
it looks like we could open a model rocket forum, lol
OuchProgramme
Specialist 3
Specialist 3
Posts: 371
Joined: Sat Jan 12, 2008 7:30 pm

Fri Jan 18, 2008 12:28 am

blind909 wrote:because they go alot higher and could do some damage when it comes down from that hight.
Actually there are such rockets as parachute, or "break nose" rockets.
The nose of the rocket blows off, or the body snaps in half. When the body breaks, there's more air resistance, slowing the fall greatly. Also, the nose wouldn't be faced downward...
User avatar
jimmy101
Sergeant Major
Sergeant Major
United States of America
Posts: 3199
Joined: Wed Mar 28, 2007 9:48 am
Location: Greenwood, Indiana
Has thanked: 5 times
Been thanked: 17 times
Contact:

Fri Jan 18, 2008 12:12 pm

TurboSuper wrote:I read a technical manual on model rocketry (put out my Estes), which outlined how to test a rocket for stability (tie a string to the nose cone and swing it around), and to add bits of clay if it needs balancing. I'll assume their premade ones come pre-balanced.
Actually, I think you remember incorrectly. The proper technique is to find the front to back center of mass of the rocket and tie the string there. Then swing it around. If the rocket is aerodynamically stable it will fly stably, if it is unstable it'll tumble.

This works with any projectile that is meant to fly subsonic. It works with bullets, water rockets, model air planes etc.
Image
User avatar
bigwick
Private 2
Private 2
Posts: 25
Joined: Sun Jan 13, 2008 4:02 pm

Fri Jan 18, 2008 3:55 pm

no its legal. have funn
User avatar
Davidvaini
Sergeant 4
Sergeant 4
Posts: 1315
Joined: Tue May 29, 2007 8:58 pm

Sat Jan 19, 2008 5:25 am

I say let it slide. We could be a Nazi about the rules, but its not like he is launching the rocket at someone. and besides its a model rocket for goodness sake.

If however you were firing a rocket that explodes on impact that could cause a lot of damage and you were misusing it then I would say gtfo, but currently I would love to see it :D
Post Reply