Working designs for parachute ammo (with a difference...)

[Carlman]

hi all,

I own a RC helicopter and for it i purchased a mini wireless camera that transmits up 2 100m easy. The views from 100m up got me thinking..., what if i had a parachute ammo for my larger pneumatic launcher that could have the cam attached and feed the live video to me.

This thread is to ask for any designs that MUST WORK EVERY TIME, ie do not have chute failures that lead to camera dieing from a 100m+ fall. Any plans are greatly appreciated.

I would of course record the flight and post it if it works out!!

Below is a cupl of pictures of the camera:

[Ragnarok]

Quite a common idea the camera round, not so common in practise.

Sadly there is no such thing as a 100% reliable parachute.
Why not just use it on your RC heli? That's going to be safer, and won't put the camera under thousands of Gs of acceleration, and you'll still get views from nice and high up.

[Carlman]

its not so much the views that im afta its the sheer coolness of seeing it from the projectiles view

dyu happen to hav any of those "common camera round" thread links?

[homedepotpro]

you know i tried this, and i spent a lot of time on it. I used a cheaper cam. But what i realise was how huge the g forces are, the cam experiences upward of a hundred g's. That cause mine to shut off. needless to say it didn't work.

[Mr. Beaver]

you know i tried this, and i spent a lot of time on it. I used a cheaper cam. But what i realise was how huge the g forces are, the cam experiences upward of a hundred g's. That cause mine to shut off. needless to say it didn't work.

He got a point there the large amount of g's would shut it down befor it will get to the point when u need the parachute, anyway shuting down isthe nicer thing that would happen its depense anyway befor the parachute the g's i think u should try it first on low psi....

[benstern]

Nothing works all the time, especially parachute ammo.

I made this design a few years ago.
http://www.freewebtown.com/flyingsloths/parachute.htm

[Maniac]

ill post pics if i can but i had seen a small rocket that had a camera on it it was a video too. ill list how you could do it. from bottom up. bottom of tube where ingines usually go put camera up tin there and the just have the rest untouced so its like a regular model rocket. i know you might say that the gas pushes off the top come on the rocket so the parachute unfurls but i have launced model rockets out of my cannon and the parachute worked perfect every time

[benstern]

Do small rockets undergo less G forces than spudgun projectiles? I always thought that they did but I am not sure.

[BigGrib]

Yes model rocket engines produce much much much less G-forces than a spud gun projectile. In the paper enclosed with rocket engines there is a spec sheet as to how many newtons the rockets produce, i just cant find one right now.

I would actually like to see how many G's a golf ball undergoes. Someone said thousands, someone said hundreds, I believe it is between 10 and 20 most likely. If anyone can do the math I'd love to see it.

[Ragnarok]

I would actually like to see how many G's a golf ball undergoes. Someone said thousands, someone said hundreds, I believe it is between 10 and 20 most likely. If anyone can do the math I'd love to see it.

Under what circumstances? Pneumatic, combustion or hybrid? Or maybe a golf club?

Few things go through any type of spudgun without experiencing thousands of Gs.

[BigGrib]

typical golf ball sdr21 1.5" pnuematic cannon @ 100 psi

[paaiyan]

Yes model rocket engines produce much much much less G-forces than a spud gun projectile. In the paper enclosed with rocket engines there is a spec sheet as to how many newtons the rockets produce, i just cant find one right now.

I would actually like to see how many G's a golf ball undergoes. Someone said thousands, someone said hundreds, I believe it is between 10 and 20 most likely. If anyone can do the math I'd love to see it.

Well, I don't know the math, but I can say it's probably more than you think. The G-forces aren't determined by the change in velocity, but rather the rapidity of that change. Our projectiles accelerate to their top speeds at near instantaneity.

OK, looked up the general formula. Give me the final velocity of the thing as it leaves the barrel, and the time t take to reach that velocity, and I can give you the g-forces.

Screw it, just the velocity is fine. I'll just give about .1 seconds for acceleration.

[BigGrib]

try and figure for 300 feet per second that is normal for a paintball right and then figure for 600 ft per second

[paaiyan]

Assuming .1 Seconds for the time of acceleration, you're looking at about 93 G's for 300 fps, and about 186 G's for 600 fps.

Now, if the time for acceleration is less, the G's could be considerably greater, exponentially even.

[BigGrib]

huh well no shit, I was figuring a lot less, well i'll be damned