A view down the barrel.
A view down the barrel before it was connected.
A 4 ounce CO2 tank.  Harder to find these days, I had to borrow this one.  Normally used for paintball markers
An early, and poor, looking attempt at a hook layout.  There would be three barbs on it, along with a pointed top of some sort.
"Kabuki hit"  plumbing, appearing on this page just for the heck of it.  Further down the page you'll see why.
The beginning rough layout of the pneumatics.
Another view of the beginning rough layout of the pneumatics.  Also visible is a CO2 regulator connected to an expansion chamber to allow the 4 oz tank to be used.
Another view of the beginning rough layout of the pneumatics.  Also visible is a CO2 regulator connected to an expansion chamber to allow the 4 oz tank to be used.

Another view of the rough layout of the pneumatics.  Also visible is a CO2 regulator connected to the 4 oz tank, however, as it is, the tank's pin valve would not be opened since the regulator can't do that.  If the tank had an on off valve installed you could turn a knob and activate it.

You can also see I've added a wooden piece to the top of the hook, and connected the barrel.

Another view of the rough layout of the pneumatics.  Connected to the regulator is a 12 gram quick change adapter, if I had placed the 12 gram into it and closed it WOULD be activated.  It's also smaller and lighter and can be hidden better.

The Hook has been placed onto the barrel, it slips over easily, I plan to snug it up a little if possible.

OK, another option for powering the pneumatics is shown here, the large silver tank is basically a pneumatic cylinder without the internal components.  They come with opening on both ends.  

On the right side I have a 1/8" NPT schraeder tire valve threaded into a check valve (one way valve) into the tank.  To adapt this tank to power the GG, all you would need to do is use a step down fitting on the left end that would connect in place of the CO2 regulator in the above pictures.
A close up of the valve, an MJV-2 with 1/8" NPT female holes.  Threaded into them are 1/8"NPT to 10-32" fittings.  The bottom is the air in, and the right side is the output port.  Since this is a normally closed valve, when you press the button on the top air flows through and out the barrel (on the right) pushing the hook off of it.
A close up shot of the schraeder valve, check valve and an 1/8" npt close fitting connected to the air tank.  To use this device, you fill the tank via any compressor fitted with a tire filler, a bicycle pump, or a quick inflater that used 12 gram CO2 powerletts.

WOOO-HOOOO!  This thing will be so simple to build!
This picture is shrunk to fit the rest of the page, but, it's another of the gun.
Another view of the gun, giving an idea to the thickness of the gun.
Another view of the gun, giving an idea to the thickness of the gun.
A view of the grappling hook itself.

The layout of the design of the handle, with the actual internal parts set in place on it, the button is shown on the left.  An extended rod from the button to the valve will be made, and the air hose will connect to the bottom of the valve and mount flush with the bottom of the handle.  An additional spring may be fitted as a safety measure.

 

The view below shows both sides of the handle, the button, and the internal parts.  The barrel's rear will fit into the protrusion on the handle and screw into place.  The handle will connect via screws in the front and back so they remain hidden.
PAGE 2   PAGE 3  PAGE 4  PAGE 5  PAGE 6  PAGE 7   PAGE 8