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Grappling Hook Launcher

Posted: Thu Aug 11, 2011 11:17 pm
by crreed
Check Out my instructable for pretty much all the info. I also posted a youtube video of a few tests I conducted with it. ... -Launcher/

Posted: Thu Aug 11, 2011 11:28 pm
by Lockednloaded
Well it's quite an interesting design, amazing for your first actually!

There are some flaws that you could iron out to get the hook higher, the most pressing issue would be the undersized valve and the flow restriction from the tube, but just keep working on it. Congrats on the great build


Posted: Thu Aug 11, 2011 11:43 pm
by crreed
What would you recommend changing to get a better flow or better performance out of it?

Re: Changes

Posted: Thu Aug 11, 2011 11:57 pm
by Crna Legija
crreed wrote:What would you recommend changing to get a better flow or better performance out of it?
connect the barrel directly to the qev not via hose, not sure of the qev size(don't like instructable to slow) but looks like 1/2ish'' I would go for a home made one in a 1'' tee

also a way longer barrel at lest 2x what you have now and more pressure.

Posted: Fri Aug 12, 2011 1:46 am
by LovableAirGuns
Thats a very clean launcher I hope to see more from you and i think other members would to.
Great job man :D

Posted: Fri Aug 12, 2011 3:40 am
by nathanhd123
Nice gun, cool design. If I were you I would paint your fire extinqisher to match your gun and possibly all the other parts you can see.

Posted: Fri Aug 12, 2011 4:50 am
by pneumaticcannons
All I can say is make ur barrel longer but if its only grappling hooks you want to launch then don't increase you're valve size. You would only do that if you want to launch lighter objects

Posted: Fri Aug 12, 2011 6:59 am
by jhalek90
I like how you used a Nerf raider shell.

Posted: Fri Aug 12, 2011 10:03 am
by Technician1002
What the members are mentioning on the flow restrictions is related to how fast the air can exit the tank when the valve is open. You can tell this somewhat by the sound of the launcher. Long after the hook is on its way, you can hear air still leaving the launcher. This is air pressure being released that was not used to launch the hook. With a larger valve more air is used to launch the hook and the time to vent the tank is greatly reduced. Just for comparison, you can listen to the hiss on this cannon with a larger valve. As others mentioned, when launching light projectiles, the rate the valve can flow is critical. I've dented a car door with a marshmallow.

Posted: Fri Aug 12, 2011 12:53 pm
by Tim Jones
One of the drawings in your instructable refers to a regulator attached to the downstreem end of the coiled hose. I didn't see one in the part list, and it isn't evident in the photos.

Did you actually use a regulator? If so, what make and model, and where is it on the completed launcher?

Posted: Fri Aug 12, 2011 2:32 pm
by mattyzip77
That is a very cool cannon my friend!! However, from the video, it sounds like your choking air from somewheres, air that should be used to make your valve more powerful. Fix this, and your cannon will be alot stronger and have faster opening time!!!


Posted: Fri Aug 12, 2011 3:45 pm
by crreed
Thanks for all of the advice. I did notice the air hissing after it left which also indicated to me it was not be realeased quick enough. My question now is what do I use instead to increase the airflow/ how would i mkae my own QEV valve. Thanks