GoPro Model Rocket

This is a completely scratch-built model rocket designed to carry my GoPro camera. 

It is 42" tall and flies on three "E" size Estes motors, and its recovered by a 54 inch parachute. The camera is housed completely within the main body tube (not in the nose cone), which allows for great footage on the way up, and great right-side-up footage on the way down. This also eliminates any drag issues.

I've included a video of the rocket's first flight in the comment section below. 

Thanks for looking! 

Step 1: Rocket body tubes

Two 18-inch tubes were made using the method I have outlined in this instructable. Each tube was made using a 3" mailing tube as a blank.

Comments

[seamster]

Here is my first video from this rocket... probably more to follow. Thanks for taking a look!

[CharlieF007]

I love this rocket being an amatur rocket builder and i hope to build it soon. Thank you for the plan.

[Kriskras99]

And maybe a new GoPro Rocket video :)

[Kriskras99]

Can you please make an instructable on how to build a model rocket including where to put the parachute and that kind of things for the very very very noob.
(Here is homemade solid state rocket fuel very cheap but very good http://www.youtube.com/watch?v=yUYxk-y-tU8)

[sunshiine]

This is sooooooooooo cool! thanks for sharing.
Sunshiine

[Denger]

Nice bird you've designed, here. Thanks for adding the onboard camera clip -- that's not bad at all for a first flight. Happy launches... FIVE STAR 'structable.

[seamster]

thanks you very much!

[Toga_Dan]

You haven't put any weight in the nose? How does it look for stability?

[seamster]

Good question. Stability was pretty good. I did a balance test with all the motors, parachute, and camera in place by hanging the rocket from a string at it's center of gravity, which turned out to the about 8 inches above the the tops of the fins. This felt a little too far forward, but I did a stability test by swinging the rocket around and around and it went nose-forward and appeared very stable. So I didn't need to add any nose weight before the launch.

I was worried that the slightly off-center loading of the camera might cause the rocket to fly sideways, and in the flight on the video I was initially sure this is what was going on. But upon retrieving the rocket and finding one motor had failed to ignite, and based on its location to the starting position of the rocket, it seemed obvious that the failed motor was the cause of the crooked flight. I guess I can't completely rule out that the camera contributed to the not-so-straight flight, but another flight with all three motors firing will hopefully prove to me that the camera weight is dispersed appropriately. (I'm pretty sure it is, so I'm excited for a nice, straight HIGH flight next time!)

That's a long-winded response! Sorry. Figured I'd answer the stability question in detail because it's something I really put a lot of thought into before and after the launch. Thanks for posting the question!

[cyberviper42]

How high did it go? Do you use an altimeter or just light 'er off?

Just a note, you can never have the center of gravity too far forward. I'd recommend moving it up to right around the camera.

Based on my experience, I'd also recommend getting some engines with a faster burn time, preferably less than a second, perhaps around 0.75 or 0.8 seconds. The higher impulse will get your rocket moving faster off the pad and it will be less affected by wind, making it fly straighter and higher. More of your thrust will be used in getting the rocket upwards, rather than sideways if an errant gust pushes the rocket over. Also the faster burn time might be enough for the rocket to complete the burn before you leave the rail, thus not affecting the flight angle. You'd need a decent size launch rail/rod, but It might be doable.

Personally I go with Aerotech engines because they are pack a bigger punch for cheaper (A G80 for $18!) and they come in a wider variety of higher power engines which is what I'm usually building. (I have yet to fly anything on less than an E)

Great job making your nose cone! I usually buy mine so that I can store instrumentation in them more easily, your method is absolutely fantastic and I will have to use it for my FTC water rocket.

Update us when you get all three engines to ignite! You should have some amazing shots.

[ImageMaker]

I'd recommend against Aerotech motors for clustering -- it's too hard to get more than one to ignite at the same time. Even when the igniters work correctly, the motors sometimes sputter and smoke for as much as several seconds before coming up to thrust. If this happens in a cluster, you'll get all sorts of unhappy things.

What I'd suggest instead is using a single Aerotech F40 motor (it'll be barely less total impulse, and significantly more thrust than the three Estes E11 motors, which aren't anything like a full E impulse -- barely above a D, in fact), and if you have a slow start, all that will happen is the rocket sitting on the pad until the motor comes up to thrust.

That F40 will cost about the same as a three-pack of Estes E motors, and igniting a single motor will be more reliable than three of even the easy-lighting Estes motors -- plus, you'll get a stronger and more stable launch with the higher thrust.

[cyberviper42]

I agree about the clustering. I didn't specify, but all of my rockets have been single engine aerotech vehicles and I think the only problem I ever had was a bad ignitor. Even a three-year-old engine that hand't been properly stored still ignited magnificently.

[seamster]

I miss-typed the center of gravity bit up there, I meant "too far back".. I do know that much, but thank you for pointing it out:)

I think Aerotechs are actually made really close to where I live, so I'll have to give them a closer look.

Regarding altitude, I was set up to do the streamer-drop method, although it's not very accurate and there are almost too many variable for it to go off with out a hitch. (Here's one link to that idea.)

Thanks for your helpful comments. Hopefully I'll get another launch off soon!

[Toga_Dan]

I've cast some nosecones hollow. See my -ible "30 rockets for $5" I don't know if that technique would be strong enough at this scale, but that would give room for instruments.

I may also have to do an ible on howto make transparent nosecones.

[nuclear12321]

What I actually have done in the past when my rocket lost a parachute and a nose cone (long story involving a tree over a river behind a fence) is build the parachute out of the bottom of a 13 gallon garbage bag, a square 24" parachute with 4 straws for stiffeners and the nose cone out of construction paper and an index card. It's actually quite simple. You fold a tiny bit going the long way over and then just keep wrapping the paper around that. To tighten it there is a little flap that sticks out, so just move it inwards, and to loosen it just let it go. loosen/tighten it until it fits snugly in the rocket and tape it closed. Then put a piece of tape in the rocket that's folded over onto itself to stop the nose cone from pushing itself in during flight. Next, do the same thing with the index card so that it fits nicely over the main nose cone. This decreases the size of the hole in the nose cone greatly and tape it on to the main nose cone. what you now have is a nose cone that cost you 5 cents to make, and has a replaceable tip if you don't feel like attaching it to the body of the rocket so that it comes down slowly. I've tried it. It works.

[Toga_Dan]

Why did u put cam in body, not nose?

You're saying cam is off center, not centered on the long axis of rocket?

Have u learned anything about gettin multi engines to fire? You wire in parallel, I assume? I'm thinkin maybe if you add voltage, maybe get 36 V on ignitors, + they'll all light fast. Sometimes ignitors seem to take several seconds at normal voltages.

Take a look at my -ible in the education contest "30 rockets for $5" Also, I'm eventually gonna launch a cam from my airgun featured in -ible "monkey hunter physics" and "harpoon/grappling gun" Which is also in this here "spy challenge"

Cool rocket. I may have to put a vote in 4 ya!

[ImageMaker]

From my experience (long ago, now) Estes igniters will pop quite nicely on 12 V as long as you have enough current available -- you'll need at least a motorcycle battery (lead-acid gel or liquid electrolyte type) or other high current rechargeable type (nickle cadmium or nickel metal hydride, or high current lithium ion). If you can't deliver at least two amps per igniter, you'll get slow ignition (and best to at least double that figure for the Aerotech ribbon style igniters).

[jsgraham]

Since you have a good uniform shape, you could have covered the foam with a releasing agent. Then you could have layed up about 3 layers of 3-lb/sq inch fiberglass cloth with epoxy resin. Then slipped that off of the foam, and saved youself some weight. I've done this many times for high power rocket projects and heavier fiberglass cloth or carbon fiber. Good instructable.

[seamster]

Thanks!

[boot2skull]

Great work. Glad to see everything came together nicely! Love the HD video on the GoPros. The video looks very detailed. Perfect launch area too.

[seamster]

Thanks! The town I live in is surrounded by lots of wide open fields. The trick is to shoot off your rockets, retrieve them quickly, and get out of there before the farmer shows up and tries to shoot you for trampling his crops.

[Covert Koala]

Great work! I've been trying to think of a good project for my old Vado camera and I love rockets. Oh and nice job with the parachute.

[seamster]

Thanks, I'm glad the chute worked!

[earlyflyer]

This step could have been an instructable by itself! Nicely done.

[seamster]

I know, I was tempted to write it up properly but I was in a hurry. Perhaps I will after I make another one and work out the little issues that I ran into with this one. Thanks!

[Adambowker98]

This is so awesome! Can't wait to see you fly it!

[arochester]

A picture taken with the camera would be nice...