Topic: SABRE - Semi-auto, but really easy
Given that a few others are discussing their contest entries at NerfHaven, I thought it might be worthwhile to discuss my planned entry in semi-private here.
I had planned to do an air gun even before VACC's offer was made. This is no surprise. In fact, the basic idea behind the gun I'll be making I thought of last year and discussed in some detail with YakMan on IRC. I had assumed YakMan would make a gun along the lines we had discussed, but life seems to have taken over and that hasn't happened yet to the best of my knowledge.
My basic idea is summarized like this: LRT + QEV + DCV + hopper. My basic idea is to use latex tubing as an air source along with a DCV and QEV as the firing system and a hopper as the advancement mechanism. SABRE stands for semi-auto, but really easy, and that encapsulates my goals here. I am looking to bring semi-auto air guns to the masses.
Latex tubing is being used very intentionally. In the past I decided against using latex tubing for my high energy efficiency Nerf guns as they don't have very high pressure, but as efficiency is not a high priority here, latex tubing's other advantages help. The price will be lower than a regulated system. Latex tubing is simpler than a regulated system. Perhaps most important for this contest is that the pressure of the tube can not easily be increased without someone noticing. This should help with those who are completely scared of air guns and the possibility of increasing the pressure without anyone knowing.
The basic structure of the gun is set. I intend to use telescoping PVC pipes as the superstructure. The inside tube will be a container for the latex tube and the outer tube will be a tracked pump. This, at least, is the goal.
I had debated whether or not I should use transparent tubes as I would be able to check how full the latex tube is more readily, but I decided the costs made it inappropriate for this contest. This is certainly an option for those without a limit on costs.
I'm going to assume the latex tube 5234K83 on McMaster-Carr is okay for this project, but later I will test other tubes to see if I can keep the same performance and get more shots per fill.
I've also decided what pump I'm going to use: http://www.amazon.com/Gamecraft-MSHNINF … B0000BYSQE
I can use ball pumps because my pressure is far lower due to the use of latex tubing.
That's basically all I've planned so far. I'm going to start thinking about how to place everything well.
I'd appreciate any thoughts.