Posted: Fri Jun 11, 2010 9:35 pm
Correct, the piston is free to slide on the rod between the nut in front and the small pin in back. I didn't get a good picture of the pin in back. Sorry for the fuzzy shot. I took the photo and looked at it later. Here the pin is through the rod, bent on both ends, and the second end is ready to be cut short and pressed flat against the rod. This makes the rod 1/8th inch larger in diameter with the folded over pin. The pin is now small enough to retract into the stop assembly behind the piston. The marshmallow cannon is exactly this way, except the rod is much smaller so the pin looks huge.
The rod is pushed in and the pin in back pushes the piston closed. The rod and nut extend out the front of the piston. To fire the rod is pulled back. The piston stays in place until the nut goes inside the piston and hits it. At this time, the reset pin is safely out of the way for the piston to be blown back at high speed by the air pressure.
Without that feature, at 100 PSI the rod would try to go through your hand with over 300 lbs of force when triggered.
Instead it flies back freely and lands safely in the bumper.
The rod is pushed in and the pin in back pushes the piston closed. The rod and nut extend out the front of the piston. To fire the rod is pulled back. The piston stays in place until the nut goes inside the piston and hits it. At this time, the reset pin is safely out of the way for the piston to be blown back at high speed by the air pressure.
Without that feature, at 100 PSI the rod would try to go through your hand with over 300 lbs of force when triggered.
Instead it flies back freely and lands safely in the bumper.