cheapie dual action balloon pump (see makeitgo's balloon finder)
2" ID PETG (I used a broken fish tank python)
3/8" square rod (I used white oak)
some small set screws
2" of 1/2" PVC
2.5 [k26] springs
ace #2 spring
hot glue and gun
Grab a NF shell, I had a clear one. It needs to have a catch, a trigger and well the shell..
Cut to the spring rest and right above the second ridge on the trigger (yes you are cutting down the trigger)
Mark on your PETG where the shell touches the tube, and cut about 2" into the PETG
test fit it, it should slide over the nerf signs, giving you plenty of room to attach it with set screws
Moving over to the soon to be plunger head. I had used a balloon pump head as a plunger head on my longshot Xbow. simply pull/ or snip it off
take the O ring out and you will notice this gap, that will not be good for our seal, so fill it up with hot glue and foam.
snip the tabs on the pump head
Now rough up the PVC and the plunger head, and apply some CA glue, clamp it and let it set.
Dump about a 1/2 a stick of hot glue into the PVC, and jam the 3/8" square rod, trying to keep it centered.
now drill, and screw in 4 set screws, be careful if you are using wood, you dont want it to split.
Now make your catch slots, I set mine about 6-7" back from the PVC. they should be no more than 1/8" deep.
Slide your springs on, and re assemble.
almost full compression.
Shoots way too far, can't be shouldered, but its worth it. I don't have a barrel long enough for it at the moment, so I used a really long RSCB to compensate for the massive amount of air this puts out and a 14" barrel. Shoots further than my BBUMB.
Is this necessary? No shit its not. but definitely scores big on the "Whatthefuckisthatandwhyisitsobig" scale.
Edited by The lord of fish, 17 June 2011 - 06:18 PM.