Instructables

Step 10: Camera bay cover

Picture of Camera bay cover
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The camera bay is covered by a piece of plastic cut from a 1-liter soda bottle. It is taped in place with clear tape once the camera is turned on and placed in the bay in preparation for flight. 

I'm excited to get some great shots with it. Watch out neighbors!
Toga_Dan2 years ago
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!
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).
Toga_Dan2 years ago
You haven't put any weight in the nose? How does it look for stability?
seamster (author)  Toga_Dan2 years ago
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!