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Posted: Wed Dec 05, 2007 2:30 am
by Carlman
paaiyan that is a cool design!, i dont really want to go the fuse way though as im in oz and you cant just go and buy a fuse, but maybe a sparkler?

JSR, th cams that are built for rockets must be stonger than my 1, u could prob think of mine as DWV and a rockets as SCH40, the rocket 1 is rated lol

So u rekon if i were to fill the cam with epoxy it would hold up? Just wanna make sure before i do it.

The cam and reciver is 2.44 (gigahertz/megahertz?, dunno which) so u happen to see 1.

Thnx guys.

Posted: Wed Dec 05, 2007 2:55 am
by jackssmirkingrevenge
the important this is that the lens is clear and that all the components in the circuitry that can break off or be dislodged are encased in epoxy.

Technically it should still work but don't blame me if it doesn't :wink:

Posted: Wed Dec 05, 2007 3:25 am
by BigGrib
hey carlman if you need fuse i can send you some cannon fuse waterproof even

Posted: Wed Dec 05, 2007 3:52 am
by jackssmirkingrevenge
How much did you buy the camera? 'cause thinking about it, it might just be a better idea to just buy this for 80 bucks. Of course you'd lose the live feed but at least you'd cut your losses if something goes wrong.

Posted: Wed Dec 05, 2007 5:35 am
by Carlman
hey biggrib, yea if i go with that ill take u up on that offer thnx m8, u in oz?

yea jsr, i do want the live feed tho good idea thnx

Posted: Wed Dec 05, 2007 6:11 am
by jackssmirkingrevenge
how's this for complicating your life, make a spudgun launched glider with flip-out wings or a scissor wing - it will be heavier, so less acceleration meanign less stress on the camera, plus it has the potential to fly a lot further.

Posted: Wed Dec 05, 2007 12:17 pm
by jimmy101
jackssmirkingrevenge wrote:
You can buy a camera for Estes rockets that'll handle rocket's g-forces (a couple hundred g's IIRC). Might be able to handle a low power spudgun's g-forces.


You can're really compare rockets to spudguns, the acceleration of a rocket happens over a much longer distance while a spudgun reaches maximum velocity in the length of a barrel. Then again, a spudgun might reach a lower maximum speed so it still would be a good starting point.

http://www.hammacher.com/publish/74349.asp

http://www.apogeerockets.com/Estes_Astr ... Rocket.asp
Jack, you would be surprised, water rockets typically pull 100~200 G's at launch. I looked it up and Estes rockets only do 10~30 G's.

A 300 FPS spud gun with a 3' barrel has an average accelation of about 470g. A lot more than an Estes rocket but not that much more than a water rocket (only a factor of 3 or so :D ).

Posted: Wed Dec 05, 2007 12:51 pm
by jackssmirkingrevenge
:shock:

Water rockets accelerate better than their solid propellant burning cousins?!

Someone should tell NASA :D

Posted: Wed Dec 05, 2007 2:38 pm
by BigGrib
Jack, you would be surprised, water rockets typically pull 100~200 G's at launch. I looked it up and Estes rockets only do 10~30 G's.

A 300 FPS spud gun with a 3' barrel has an average accelation of about 470g. A lot more than an Estes rocket but not that much more than a water rocket (only a factor of 3 or so :D ).
umm check on page 2 of this thread, because i did the math at 300 fps and a 3' barrel and it's almost twice as much coming in at 928.57 g's

Posted: Wed Dec 05, 2007 3:56 pm
by dewey-1
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Posted: Wed Dec 05, 2007 9:55 pm
by Carlman
JSR i LOVE that design, and i could make it too!!, could it be made out of wood such as pine or even balsa then add wieght to balance it?

Posted: Thu Dec 06, 2007 12:14 am
by jackssmirkingrevenge
Carlman wrote:JSR i LOVE that design, and i could make it too!!, could it be made out of wood such as pine or even balsa then add wieght to balance it?
It can easily be made out of balsa, the fuselage could be a section of thin balsa rolled into a tube, quite easy to achieve and the result is very strong and lightweight. I improved the design slightly, in this way the wings and the fins act as stabilisers in the barrel (which also serves to keep the wings closed) - though of course you'd need a sabot of some sort to seal the air.

To open the wings you can use internal rubber bands that pull them out, as with this design. Ideally the wings should open when the glider reaches maximum height, you can do this by using relatively weak rubber bands and a locking mechanism that keeps the wing open once they do. This way, air drag will prevent them from opening out too early, and they will then be prevented from closing once it starts to accelerate again.

edit: interesting links there dewey, electro-chemical eh? I guess when the rocket starts pointing downwards you could have some acid spill onto baking soda creating enough pressure to blow out the chute...

Posted: Thu Dec 06, 2007 2:53 am
by Carlman
OMG you are the master JSR but im sur every1 knows that lol

yea that design worx for me im pretty handy with a chisel and a stanly so balsa would be ideal for me. that baking soda and acid seems the easy way to go rather than a hard to get pyrotechnic fuse (damn oz). why would you want to have the wings open at maximum altitude thats also when the chute opens thus rendering the wings useless or so i would think, are they to reduce spin? or what is there purpose?

and by the way are you involved in tech drawing for a job because they arnt just some thrown together 2 minute plans there

Posted: Thu Dec 06, 2007 3:02 am
by jackssmirkingrevenge
yea that design worx for me im pretty handy with a chisel and a stanly so balsa would be ideal for me. that baking soda and acid seems the easy way to go rather than a hard to get pyrotechnic fuse (damn oz). why would you want to have the wings open at maximum altitude thats also when the chute opens thus rendering the wings useless or so i would think, are they to reduce spin? or what is there purpose?
You got me wrong, I meant that a winged glider could be used as an alternative to a parachute, not in conjunction with. The idea is that while it's rising, the wings are closed so the projectile is aerodynamic and flies quicker up to the maximum altitude, at which point the wings will fold out (because it's moving slower and there's less air drag keeping them shut) and the unit will glide to earth - a little swiftly, because presumable the wing loading (area to weight ratio) will not be so low, but safely enough.
and by the way are you involved in tech drawing for a job because they arnt just some thrown together 2 minute plans there
Actually they were :) I'm a laboratory analyst by trade, but I do like to dabble in technical drawing. The plans were sketched with a pen on paper, I then took a photo with my digicam, opened it with paint and saved it as a monochrome bitmap, inverted the colours to give that "blueprint" look et voila :)

Posted: Thu Dec 06, 2007 3:11 am
by Carlman
would it 'glide' and hit slow enough to preserve the camera though?

and that is a really good and sneaky idea for pofessional looking drawings in 2 minutes lol

what kind of lab work u in?, ive just finished skwl and am considering lab tech/analysist as a career