This an under barrel grenade launcher on the cheap I have another instructable showing how to make the interchangeable airsoft shell tubes here. it costs about $25-$30 in plumbing parts at ace hardware and it shoots old D batteries wrapped in plastic bags :).
I fill the pressure chamber (white tube) up to 150psi because the ball valve is the lowest rated part on the whole thing.
Step 1: Gathering Materials
You will need:
(1) 3/4in ball valve*
(2) 3/4in threaded couplers*
(2) 3/4in to 1 1/2in brushing
(1) 1 1/2in end cap
(1) threaded bike valve**
+1 1/2in PVC pipe ~4-10in depending on your preference, I am using 6in chamber
*If you get a threaded ball valve you don't have to glue anything together
**this is the part in the picture, and it is a different part than what is on the back of the gold launcher in the previous picture
I am making this instuctable after I already built the launcher, so I don't have pictures of the individual parts :( ....sorry.
Step 2: Rear Assembly
Using epoxy or PVC glue, attach the endcap to the 6in piece of PVC.
Step 3: Rear Tube Assembly
Next, attach one of the couplers to the part in step one and add a brushing on top of that.
Step 4: Valve Assembly
Wrap the threads of the couplers LIBERALLY with Teflon tape and screw in the threaded couplers to both sides of the ball valve.
Step 5: Barrel Assembly
Attach the last coupler and brushing together with glue like in the picture, and screw that onto one side of the ball valve and screw the brushing/coupler/endcap combo onto the other side.
Step 6: Fill Valve Insertion
Drill a hole that is to small for the valve and use the valve to tap threads into the PVC by twisting it in and out.
*There should be at least an inch gap there because that is where you put the valve........not on the back, because then you can't brace it against your shoulder
Cut whatever size piece of PVC you want so you can go play with this thing :D just don't make it longer than the launcher itself.
For ammo right now you can use pennies wrapped in a plastic bag 50cents worth works great for me.
DON"T SHOOT AT PEOPLE!!!! PENNY LOADS ARE NOT FOR AIRSOFT........IT WOULD BE LIKE SOMEONE KICKING YOU IN THE HEAD FROM 100!!! ft AWAY!!!!!!!!!!!!!!!!!!!!!!!!
I'll show you how to make the airsoft shells in the next instuctable....and i promise there will be pictures for that ;-)