This is my entry for HoF in the NIC Homemades Contest. I actually thought of using check valves a long time ago, but the price deterred me from ever experimenting. Now that there's a big ole contest, I decided to finally try it.
First, the pieces you need
1.5" PVC, 1.5" Coupler, 1/2" CPVC, 1/2" Conduit, 1.5" Check Valve, 1.5" to 1/2" T, (2) 1.5" to 1/2" Reducer Bushings(one threaded, one not), 1/2" to 1/4" Threaded Reducer Bushing.
As you can see, I took the first 1.5" Bushing, coupler, and 1/2" to 1/4" bushing and put them together with a 1/4" to Schrader valve
This will need to be glued into the end of the check valve with the arrow pointing to it
Disregard the sloppy primer job. My finger is now purple too.
Next, grind out the ridge in the other bushing so that conduit can slide through it
Put a 3" piece of the conduit in there.
Next, connect the T with the check valve, no glue needed, and put the bushing in the other end. Slide CPVC through until it touches the valve, and mark it. Cut a piece about 1.5" longer than the mark
Next, slide the CPVC into the conduit/bushing assembly, and put an endcap on the inside end of the CPVC
Next, cut the finger off a rubber glove, and slide it over both the conduit and CPVC
Glue the finger to both conduit and CPVC
Slide the bushing into the opposite end of the T as the valve. Add a barrel, and you're done
With my improvised arrow barrel shown above, and 1 pump from a standing bike pump, an arrow goes between 93' and 101' consistently. It gets 127' to 135' with slingshot weight streamlines and an even more redneck barrel.
The only problem with using such a large check valve is that it is very difficult to push after very much air is pumped in. Will soon have a version with a smaller valve to see if there is any change.