Flaming Hilt

I still want to know who that person is who's hanging from the ceiling.

I'll stop by the Associated Students' office and report back on the success of vehicle reservation.

This looks awesome! But I'm not quite clear on the O-ring. Is it glued around the inner edge of the tee(like concentric circles)? What's its function? Thanks.

The concentric circles idea is correct. The function of the O-ring is to reduce air leakage out the hole for the trigger, so that as much air as possible is used to propel the dart forwards (instead of leaking out around the trigger).

For the trigger setup is the screw supposed to be screwed into the check valve? What length screw are you guys using for the triggers ( if it helps I am planning to use the pvcT setup) or it doesn't really matter? Also any tips on hole to drill into the center of the tee?

arfink already covered this a wee bit but I wanted to add notes for my specific design.

As specified in the write-up, I'm using a 1/4x4 lag screw. This means it's 1/4" in diameter and 4" long. For 1/2" PVC with the tee directly connected to the check valve I find this to be the perfect length. I like lag screws because they have pointed ends, so they are easier to get started in a non-pre-threaded hole than a hex screw.

The screw is screwed into the valve part of the check valve -- that is, the piece that moves. If you stare down the front of your valve (the end that air only comes out of) you should see a small cylinder of PVC on the inside -- that's what you want the screw attached to.

My tip for drilling the hole is this: slow and straight.

I feel like this would make a nice attachment to any gun. That is to say, like people used to do with SSPBs on NFs. You could slap this on the bottom of a SNAP and have a nice little lefty-fired backup that nobody saw coming when they rushed you, thinking you were out of ammo.

The semi automatic idea might work better if you had a larger chamber between the ball valve and the check valve, as (At least I think after reading SG Nerf's post) that is the air used for firing the dart if you use it as a semi automatic blaster.

This is wise. I will try adding a small chamber (perhaps just a T with an endcap on the outlet) and post the results.

I acknowledge SGN's reservation that this will take air from the main chamber, but right now I think I'm getting a semi-auto effect, just a weak one. IE, pulling the trigger makes the same magnitude of "pop" each time (and thus I assess, the same pressure of air is being released, which is what we want), but this "pop" is hardly strong enough to get a dart out of the barrel.

EDIT: After watching 3DBBQ's semi-auto demonstration (which I have posted in the semi-auto section of the write-up) I note that his active air tank (the part between the ball valve and the check valve) is about as big as mine. I would conclude that he just pressurizes his tank more than I do, but (by my guess) we're using equal size pumps and pump relatively the same amount of times. Perhaps I just have bad luck with air guns.

For my unit, i simply adjust the ball valve opening until i get it to fire in semi-auto, then i leave the ball valve in the same position for the duration of the entire Nerf game (or until i want to increase or decrease the air flow to adjust the shot power). The blaster can be pumped up multiple times after that without re-adjusting the ball valve. I guess its pretty much like adjusting the air regulator on an air tank device.

I understand where you're coming from and think it a valid point, but I would like to be able to switch on and off the semi-auto mid game. Of course, with practice I'm sure I can find that perfect spot in just a second or two.