DMRocket 2.0

[blike]

After the success of my first video rocket, I've decided to try and push the boundaries of model rocketry--with a video camera onboard. The goal of this rocket project is to boost an onboard digital movie camera over a mile high (1.61 km) and successfully recover it.

 

The main challenge as I see it will be recovery of the system. The rocket I have built for the project (seen below) will not be visibile at that altitude. I'm also limited by the small size and general inavailability of fields around town. Because of this I've decided to go with a 2-stage recovery. The plan is to have an altimeter fire a charge to eject a 7' (2.13m) streamer at apogee to help find the rocket in the sky. The streamer is not designed to slow the rocket's descent, merely stabilize it and provide a visual reference in the sky. Then, around 300 feet, the alitimeter will fire another charge and deploy the main chute. This way, the rocket is not subject to long drift times under the main chute (imagine how far it would drift if the main deployed at 5280').

 

The second challenge of this project is to design a two-stage system out of a one-stage rocket. I've already completed the construction of the main rocket body, but I need to add another booster stage below the main booster. I ran the rocket I built through a simulator which estimated it to fly around 3000 feet on a G-sized motor. I estimate that if I stage a G and F motor, the rocket will clear 5000' easily.

 

I'll post more pictures as I build and install the camera and staging systems

[YT2095]

6000+ (depending on weights involved) would be more likely!

 

dude that looks so sweet! your plan seems perfectly workable providing all the electronics and deployment charges work out for you (a silly drop of glue in the wrong place can mess it up! I know!). I`m just so looking forwards to the new Vid )))))

the last one was great, this should look way cool falling from that height, esp stabilised!

lemme give you a tip though, it`s something I`ve done on all my rockets and balloons. Write you Mobile fone number on it, and state Reward Offered if found, never state the amount of the reward (someone may thing the cam is worth more!), and only ever a mobile number for safetys sake

Good luck and God Speed dude )

[Crash]

what a messy garage...

good luck

BTW whats the reward?.......

[blike]

We use our garage as storage, not for cars :}

 

The reward happens to be a pat on the back from myself.

[fafalone]

Yeah, you don't have a car worthy of garaging. Camry, roflflfl.

[Cap'n Refsmmat]

A suggestion:

Use a drogue, not a streamer, it'll slow the rocket down a bit and stabilize it.

Maybe you should go to LDRS (Large Dangerous Rocket Ships) next year with it. I like watching them CATO!

[Hades]

awesome! i hope everything works out well for you. When i was younger, i thought if i used a strong enough engine, it would propel my heavy rocket as high as intended. Mind u, i had so much trust in the large engine, i made the rocket without using light materials. A pvc tube, aluminum fins, and a cedar nose.... it lifted off 50 feet and then came straight down into me mum's windshield..

[Crash]

So i decide to keep the rocket i found due to a lack of reward

Did you buy a kit for this? or did you build it yourself?

[blike]

oh, the reward for finding the rocket? Well, return it and you shall see

 

The body tube and fins come from an existing kit, but the design is sort of my own. The inside of the body tube and nose cone are vastly modified to accept an altimeter and video camera.

[Cap'n Refsmmat]

I took this "rocket science" class where we made a 2-stage rocket w/payload bay. On test day, mine shot up a couple hundred feet, then, as it staged, it turned horizontal (aaa!) and nearly went over the highway.

Problem is, this kid went running for the booster, and ended up jumping on it.

 

Another kid's went STRAIGHT up, and as it glided down it went right across the highway and into some trees.

 

My dad once launched one, but the engine died a few feet off the pad, so it tipped horizontal, then re-ignited, and crashed into a hill.

[Dave]

blike said in post # :

oh, the reward for finding the rocket? Well, return it and you shall see

 

The body tube and fins come from an existing kit, but the design is sort of my own. The inside of the body tube and nose cone are vastly modified to accept an altimeter and video camera.

 

Was interested in the post (always wanted to build my own model rockets, but didn't know where to start so I haven't), and stumbled across this. Thought you might be interested so decided to post

[Radical Edward]

how about a smoke can for a trail?

[Cap'n Refsmmat]

Model rocket motors already do that quite well.

[blike]

True, but I think RadEd was referring to a way to track the descent. I actually tossed around the idea of some sort of smoke canister that would ignite during descent. The problem is that the altimeter has a limited number of capacitors, and two of them will already be busy (one will ignite ejection charge, one will ignite the second stage motor). Maybe I can extend the smoke bomb's fuse so as to burn for around 12 seconds. That way I could use the motor's discharge to light the fuse..

[YT2095]

need any help, just ask )

[blike]

Dave, thanks for that link! I don't think I have the experience necessary to attempt to create my own accelerometer (or altimeter). I found some relatively inexpensive ones that are designed for rockets in that they have capacitors and things onboard and will discharge at certain altitudes.

 

YT, I'm definitely going to need help designing the dual deployment. I have to make my own ejection charge, but I havn't a clue how to go about it!

[Radical Edward]

you could always just have a little radio pinger. Radios aren't too hard to build.

[Cap'n Refsmmat]

Take an old RC radio thing and put the receiver in the rocket. Instead of servos, you can make it control whatever you want.

[YT2095]

you`ll need a loose black powder charge for that, it`ll give you the gas volume you need with a reasonably low temperature and at a non explosive rate, if you have any boric acid, soak some kitchen tissue paper in it and let it dry, use that to wrap the charge in, the boric acid will make it fire proof, use sewing cotton to tie the charge together into a package, don`t use tape, we don`t want it to explode and you`de risk it being too tight.

will those cap discharges activate the "solar ignitors"?

if not then you`ll have to use a flash bulb, they only need a few volts to trigger

use proper comercial grade BP too, don`t bother making your own, use a box knife and cut the plastic just above the metal on a couple of shotgun shells, that`ll be about all you`ll need per device if you get stuck for BP.

[Cap'n Refsmmat]

Use pressurized CO2 for parachute charges. Much better for higher-flying rockets.

[blike]

Thanks YT!

 

Cap'n refsmmat, that sounds like a great idea. I would just need to find a way to activate a CO2 cartridge or something.

[Cap'n Refsmmat]

I got the idea from Aurora, a rocket built by amateurs that made it to 30,000 feet.

Hold on... I'll find their site... http://www.aurorarocket.com/aurora/rocket.htm

Their website said:

 

The gas is released by the modified Rouse CO2 "puncture" devises. Both firing devises also have the ability to accept redundant Davyfire’s to initiate the system. This allows both altimeter systems to fire both CO2 bottles.

We learned during testing that the ideal way to use the CO2 system is to restrain the separation joint with a method, such as sheer pins, that will give a repeatable and measurable resistance, and insure you achieve an internal 10 or 15 psi before the joint releases. Then the nose'll really “pop” off. For those trying this at home using pistons, 8 to 10 psi should do the trick. Be sure to use the right size vent. Other than that, your rocket should also be considerably airtight.

[YT2095]

pressurised CO2 is heavy, a min of 12.5 grams of gas for the smallest, the metal weight is added ontop of that.

and easier way would be to spring load it, and use fishing line to keep the spring back, wrap the line around a visco fuse a few times at what ever timing you want (a 10 cm fuse is typicaly 6 seconds burn time), as the fuse burns it breaks the line under tension and releases the spring

probably a little lighter and safer to use than my 1`st idea and lots easier to obtain

[Radical Edward]

I know this is a horrible thread bump, but how is this project going?

[slickinfinit]

Kool I am a avid rocketeer it is good to see a post with my hobby in it. I started buying them from the store now I make em from scratch and still they are very difficult to get them do do what u want I will post some pic when I get a digital cam and post em I made some unique lookin ones lol and I like to make my own engines. The science of getting your solid fuel made so it works realy helped me lean basic chemistry since i never went to high-school I am makin a 15 foot tall shell for my next big flyer and want to get the apogee at 5000 meters high lol that will be very tough the highest I measured at was less than half that with self-built motors but I am just gonna make em 3 times as big and hope fro the best lol.I try to get pic soon