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| Carlman |
 Posted: 12/02/2007 11:19 AM Post subject: Working designs for parachute ammo (with a difference...) |
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The Aussie
Joined: 24 Nov 2007
Posts: 1113
299.69 Spud Bux
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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:
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| Ragnarok |
| Posted: 12/02/2007 11:51 AM Post subject: |
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Lord of Karma
Joined: 19 Dec 2006
Posts: 2093
5365.58 Spud Bux
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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. |
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| Carlman |
| Posted: 12/02/2007 12:07 PM Post subject: |
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The Aussie
Joined: 24 Nov 2007
Posts: 1113
299.69 Spud Bux
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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? |
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| homedepotpro |
| Posted: 12/02/2007 13:43 PM Post subject: |
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Lieutenant Colonel
Joined: 26 Nov 2006
Posts: 437
429.31 Spud Bux
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| 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. |
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| Mr. Beaver |
| Posted: 12/02/2007 14:11 PM Post subject: |
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Corporal
Joined: 30 Nov 2007
Posts: 66
169.79 Spud Bux
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| homedepotpro wrote: | | 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....  |
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| benstern |
| Posted: 12/02/2007 14:31 PM Post subject: |
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Joined: 21 Sep 2005
Posts: 887
126.17 Spud Bux
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| Maniac |
| Posted: 12/02/2007 17:09 PM Post subject: |
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Lieutenant Colonel
Joined: 23 Oct 2007
Posts: 478
538.65 Spud Bux
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| 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 |
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| benstern |
| Posted: 12/02/2007 18:55 PM Post subject: |
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Donating Member
Joined: 21 Sep 2005
Posts: 887
126.17 Spud Bux
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| Do small rockets undergo less G forces than spudgun projectiles? I always thought that they did but I am not sure. |
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| BigGrib |
| Posted: 12/02/2007 19:22 PM Post subject: |
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GribNation Founder
Joined: 01 Oct 2007
Posts: 624
207.65 Spud Bux
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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. |
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| Ragnarok |
| Posted: 12/02/2007 20:08 PM Post subject: |
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Lord of Karma
Joined: 19 Dec 2006
Posts: 2093
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| BigGrib wrote: | | 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. |
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| BigGrib |
| Posted: 12/02/2007 21:20 PM Post subject: |
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GribNation Founder
Joined: 01 Oct 2007
Posts: 624
207.65 Spud Bux
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| typical golf ball sdr21 1.5" pnuematic cannon @ 100 psi |
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| paaiyan |
| Posted: 12/02/2007 21:35 PM Post subject: |
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Ascendant Defenestrator
Joined: 27 Dec 2006
Posts: 2055
2622.52 Spud Bux
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| BigGrib wrote: | 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. |
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| BigGrib |
| Posted: 12/02/2007 21:58 PM Post subject: |
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GribNation Founder
Joined: 01 Oct 2007
Posts: 624
207.65 Spud Bux
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| try and figure for 300 feet per second that is normal for a paintball right and then figure for 600 ft per second |
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| paaiyan |
| Posted: 12/02/2007 22:02 PM Post subject: |
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Ascendant Defenestrator
Joined: 27 Dec 2006
Posts: 2055
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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. |
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| BigGrib |
| Posted: 12/02/2007 22:07 PM Post subject: |
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GribNation Founder
Joined: 01 Oct 2007
Posts: 624
207.65 Spud Bux
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| huh well no crap, I was figuring a lot less, well i'll be damned |
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