Coaxial (kinda) Cannon
Posted: Sat Jan 19, 2008 7:49 pm
This is my version of PVC Arsenal 17's Fish Killer 2 (http://www.spudfiles.com/forums/fish-ki ... 11714.html). I was looking for something different to do and this ingenious design caught my eye, although it occurs to me that I didn't ask PVC Arsenal 17 for his permission, so I hope it's okay.
Anyway, I took his design and scaled it up to 3/4" barrel and a 2" by 1.25" chamber. The barrel is five feet long and the chamber is about three feet long. The barrel slides through the inner 1.25" pipe of the chamber, but I won't go into detail on this because it is explained in the Fish Killer 2 topic. The main changes I made were:
-I used the Bolt action breech found on this website
-I used a 1" modded sprinkler valve piloted by a cheap home depot blowgun and a ball-valve safety
- I moved the trigger forward using a very simple triggering mechanism that allowed me to reduce the pilot volume drastically (Thanks to JSR for this idea).
-It's a lot bigger (and pretty heavy)
So far it is powerful but not hugely so, probably because of all the restrictive 1" pipe I used to accommodate the breech loader. The other flaw is that I did a poor job of controlling the primer (next time I will probably use the clear stuff). I have not painted it because I do not want our neighbors to think I am carrying an bazooka or something around, so any suggestions for non-intimidating color choices are welcome. I am also afraid that because of all the 90 degree elbows and 1" pipe that is so restrictive that part is liable to blow up, and I stick my arm through the opening in between them, placing the pipe that could explode right over my heart and by my face. Oh joy. Now for some pics:
Anyway, I took his design and scaled it up to 3/4" barrel and a 2" by 1.25" chamber. The barrel is five feet long and the chamber is about three feet long. The barrel slides through the inner 1.25" pipe of the chamber, but I won't go into detail on this because it is explained in the Fish Killer 2 topic. The main changes I made were:
-I used the Bolt action breech found on this website
-I used a 1" modded sprinkler valve piloted by a cheap home depot blowgun and a ball-valve safety
- I moved the trigger forward using a very simple triggering mechanism that allowed me to reduce the pilot volume drastically (Thanks to JSR for this idea).
-It's a lot bigger (and pretty heavy)
So far it is powerful but not hugely so, probably because of all the restrictive 1" pipe I used to accommodate the breech loader. The other flaw is that I did a poor job of controlling the primer (next time I will probably use the clear stuff). I have not painted it because I do not want our neighbors to think I am carrying an bazooka or something around, so any suggestions for non-intimidating color choices are welcome. I am also afraid that because of all the 90 degree elbows and 1" pipe that is so restrictive that part is liable to blow up, and I stick my arm through the opening in between them, placing the pipe that could explode right over my heart and by my face. Oh joy. Now for some pics: