easy and works well for how long it takes
(check new step (# 6) )
Step 1: Materials
you will need:
2 liter bottle
bike pump (with needle)
two 7/8" PVC valves
one 7/8" PVC "T"
one piece of 7/8" PVC 1/2" long
two pieces of 1/2" PVC 1 1/2" long
two pieces of 1/2" PVC 2 1/2" long
one piece of 1/2" PVC at least 2 feet
Step 2: Construction
using pvc cement, put the pieces together as shown in step 1 picture.
make sure to glue all pieces EXEPT the barrel! do NOT glue the barrel to the valve as you will be taking it off to reload
Step 3: Pump
drill a 5 mm hole down 3/4 into the cork
after that, stick the pump needle into the other end all the way
Step 4: Load Projectile
take the barrel out of the valve and put your bullet in the end
(i used a marble wrapped in masking tape)
make sure its a tight fit or it might not work very well
Step 5: Launch
to launch, make sure that the valve on the handle is open and the valve leading to the barrel is closed.
then stick the cork into the bottom of the handle and pump it up.
(i usually pump 5-7 times)
when you're done pumping close the valve in the handle and unplug the cork.
after that just open the barrel valve and your projectile goes flying
Step 6: Expand on the Design
once you get the basic design down, expand on the idea!
this is what i did with mine
now its alot easier to pump