I made Sketchup drawings of two versions of my watergun. Both do not have a pressure regulator drawn in them yet (still figuring how to cost-effectively implement this), but one has a regular pump while the other has the (air/water) pump. Unfortunately, I haven't been able to post the Sketchup files, so I have screenshots. (SIMPLE DESIGN = IDEA 1 Only) (IDEA 3 Obsolete)Simple Design (Left Side):
In this design, the top barrel is the air tank, the middle barrel is the piston chamber, and the small barrel at the bottom is the pump. This is designed to hopefully be far more ergonomic than standard APH's. For the bottom tee, I'm thinking of filing a rubber sheet so that it fits between the pipes, then Gorilla gluing the PVC-Rubber-PVC sandwich for better structural rigidity. There also needs to be a strong brace to hold up the 1 1/2 ID top pipe.Simple Design (Right Side):
The simple design functions as a standard APH, with the exception of the added piston. Water is sucked from the bottom left (just shown as a 1/2'' ID pipe), which can be connected to a gun or backpack mounted water reservoir, and pushed through the side pipe of the gun into the main chamber, pushing the piston, which pushes the air. Once pressurized, (doesn't have to be completely filled), releasing the main valve makes the piston push the water out of the cannon. A Schrader valve which pressurizes/depressurizes the tank is not shown.Simple Design (FPS View and Front):Summary & Comments:
So here are some of the pictures!
As I said earlier, I am still working on the water gun with the pressure regulator to make it smaller and more cost effective. This is all supposed to be concepts anyway, and any of you can use any of my ideas and designs at any time. Right now I have no money, so this will be a later project for me.
In the original post, thanks for pointing out that I can use a check valve instead of a ball valve for the bypass. It's amazing I missed that and I was seriously going to take the unnecessary step of turning on and off the ball valve whenever I wanted to pump. About the adiabatic heating, I suppose a cycle where I put more work in the gas that it takes out would cause an net increase in thermal energy. I also don't want excess heat to reduce the pressure rating of PVC, especially for pressures above 100 psi. Would that thermal energy have enough time to accumulate before being transferred to the water and air?
For the piston efficiency, I've been able to create a 2'' one thanks to Nighthawkinglight on Youtube. With lubrication, It eats away only 2-3 psi in friction. The same type of idea should work on a smaller scale with dremeling and sanding.
I would love to see what you did for your CAPH design, thanks.Drenchenator:
For the Simple Design, I believe I've gone as basic as possible. What do you think? I'll have to calculate price, but it should be super cheap too.Concept Statistics (Simple Design)
(Range and Output Information from homemade 150-75 psi drop-off 2 inch piston cannon)Length:
2 1/4'' Shaft; 6'' maximumHeight:
463 ml (1 1/2'' x 16''); 824 ml (2'' x 16'') (Customizable)Pressure:
150-90 psi Max (Pressure Dropoff)
85x (Homemade Piston Cannon Shot 1.5L for 0.58 sec)Pumps to Fill:
15 pumps (1 1/2'' x 16''); 26 pumps (2'' x 16'') (0.546'' x 9.5'' Piston Rod)Range:
65-70 feet effective range (where most of the water lands with no wind) (80 feet max)Price (Gun Only):
(est. $60.23)Simple Design with Union