Materials needed:
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..
![Posted Image](http://img835.imageshack.us/img835/5713/img2616ct.jpg)
Cut to the spring rest and right above the second ridge on the trigger (yes you are cutting down the trigger)
![Posted Image](http://img705.imageshack.us/img705/3721/img2620g.jpg)
Mark on your PETG where the shell touches the tube, and cut about 2" into the PETG
![Posted Image](http://img844.imageshack.us/img844/2901/img2619s.jpg)
test fit it, it should slide over the nerf signs, giving you plenty of room to attach it with set screws
![Posted Image](http://img402.imageshack.us/img402/3306/img2622cc.jpg)
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
![Posted Image](http://img221.imageshack.us/img221/4920/img2624v.jpg)
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.
![Posted Image](http://img194.imageshack.us/img194/940/img2625dc.jpg)
snip the tabs on the pump head
![Posted Image](http://img806.imageshack.us/img806/3508/img2626m.jpg)
Now rough up the PVC and the plunger head, and apply some CA glue, clamp it and let it set.
![Posted Image](http://img41.imageshack.us/img41/3903/img2627h.jpg)
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.
![Posted Image](http://img593.imageshack.us/img593/8474/img2629a.jpg)
now drill, and screw in 4 set screws, be careful if you are using wood, you dont want it to split.
![Posted Image](http://img193.imageshack.us/img193/4239/img2630v.jpg)
Now make your catch slots, I set mine about 6-7" back from the PVC. they should be no more than 1/8" deep.
![Posted Image](http://img808.imageshack.us/img808/8418/img2632v.jpg)
Slide your springs on, and re assemble.
![Posted Image](http://img823.imageshack.us/img823/6691/img2633i.jpg)
almost full compression.
![Posted Image](http://img695.imageshack.us/img695/1826/img2634io.jpg)
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.