video camera recovery

[Reed Goodwin]

Hi all. I could not go to sleep last night so I started thinking rockets. One of the things I would like to do in the near future (if I could get some money) is to build a low power rocket capable of lifting my new Boostervision camera. I want the video to be of the ground almost all of the time, presenting me with issues with the usual placement of the camera in the payload bay with a mirror to look down. I figured I could get the payload bay to come down separately, but I was having trouble figuring out how to get it to recover safely and without being lop-sided or spinning too much. Then it came to me, why not put three small parachutes on it that come out when the body separates. I have attached a quick diagram I made in paint (it's awful, I know, but bear with) to help with the description.

So, here's the idea:
The camera is in the payload section of the rocket with the nosecone attached (probably by a screw or two). There are three, I'll call them recovery straps, that have one end attached to the inside of the bay where the nosecone joins, and the other end attached at the bottom of the coupler. These straps are about three times the length of the payload bay (no nosecone) and coupler. Attached a little more than a third of the way down from the NC end of the bay is the straps parachute. To prepare this for flight, the recovery straps are laid flat against the side of the payload bay and the parachutes folded and packed into the main airframe. The recovery straps have to go between the nosecone and the payload bay at the top and the coupler and main airframe at the bottom, so to accomidate that, I will cut slits in the main airframe and the payload bay to allow the straps to pass. To keep the tubes from deforming, I would glue a bit of spare tubing around the outside of the tubes, covering the slits. Now there is room for the straps to pass between the joints. Anyhow, also packed in with the three parachutes for the payload bay will be the parachute for the main airframe. Okay, so now the rocket lifts off and goes up into the air. At ejection, the payload bay and main airframe separate, each going their separate way. Now the parachutes come from under the payload bay and inflate, bringing the bay safely home with minimal spin.

I hope that wasn't too confusing. I am thinking that this would likely have a 24mm mount as I imagine a C6 might have difficulty lifting the whole thing, safely. I guess the other option would be to give it an 18mm mount and use AT composite motors, though I can't adapt up. I figure I would probably make my own parachutes for the bay as they are kind of small and I want nylon chutes (I am beginning to lose faith in plastic chutes). Someone else has probably also done this, so if you have, tell me how it went.
Thanks,
Reed

 

[Reed Goodwin]

DOH! forgot the pic.
Reed

 

[Brian62]

I think, your overthinking it. It should be just fine as is, unless you always land on concrete
Brian

 

[Reed Goodwin]

Well, I was thinking of three parachutes because that is the simplest way to reduce movement back and forth and spin, as three points provide the most stable platform.
Reed

 

[WillCarney]

On my second video flight I mounted my Boostervision camera
on the outside of the electronics bay of my first L powered rocket.
It was slightly pointed to the ground and had mostly ground shots
all the way to over 5600'. The video did cut in and out a few
times due to spinning and I lost visual track in the sun. Even with
a high gain antenna you need to "point" the antenna to the
rocket. That rocket was DD and the main did not come out. Even
though the main never deployed the camera was not damaged.
After ejection the camera did not always point down.

You could build a payload section on the bottom part of the
rocket were the ejection and chute goes thru the section but
but is sealed against the gases. The inside is accessable for
batteries and the camera mount. The bottom would always be
pointed to the ground. I did a similar setup where I mounted
lights and batteries in a lower section of a night rocket.

William

 

[Reed Goodwin]

I thought about putting the camera on the lower section, but I don't think that that is really doable on a small rocket. I could see myself doing that on a 3" or 4" rocket, maybe a 2", but that's as far as I would go.
Reed