Nerf Pull Valve

[soakinader]

So yesterday as I was cleaning the garage, I found this box with a broken SM 1.5K pump and PC inside.
Sorry, no picture yet, but air goes in through a threaded hose on one end, with a pin for the pull valve opening on the other side.
Unlike a CPS type hard chamber, there is no third opening for a rubberized PC.

Taking a look at the pressure chamber, on the front end it could actually make for a decent water pull valve. The opening at the front is at least big enough for a 5-10X ish stream.
On the back end, where the air goes in, it has a tiny little 1/8"-3/8" valve. It's tiny, so it would seriously hold up the water flow if it was used for a trigger mechanism on a gun expected to put out more than ~3-5X.

But it started me thinking. I see AT3K's, SM3K's, (not to mention 1.5K's) and various other airguns all the time when I go thrifting. (I've bought dozens of each kind and left at least twice as many behind!). So, I don't have time to look right now, but if there are any airgun PC's that are:

-strong enough for water pressure (this should be a given) also durable enough to stand getting wet (rust may become an issue)??
-big enough intake for water volume (and standard size parts!)
-big enough opening when the trigger is pulled for output volume

Food for thought right:? GTG , will do more research later!

[HBWW]

Here's an example:
http://nerfhaven.com/forums/index.php?showtopic=21237

Obviously, that design would require heavy modification to become suitable for our uses. Ideally, there wouldn't be all that dead space, although the biggest problem is attaching it to high flow internals. Nerf air blasters don't need much flow.

Aluminum might be the right material for pull valve pins, rather than the rusting garbage that's normally used. A lot of pull valves break from the back due to the rust causing the seals to break, although there are some back-leaks where this doesn't seem to be the case. Ultimately, what we need are pull valves that are easily taken apart, because all seals will break eventually.

Of course, this is just one of many components that need to be explored when investigating new homemade designs to replace breaking CPS's.

[marauder]

Kind of off subject, but I'd love to do what they did with aluminum for our own purposes.

[HBWW]

^ Homemades forum, not Nerf, so I don't think that's off-subject. The interest here is using Nerf tanks (many of which have the pull valve built-in) for our purposes. The concern is durability, but if it can work, we may be able to make something of it.

Hey DX, drill hole in naked zerker internals, attach 1L or 2L soda bottle, instant PR lololololol.

I'm tempted to experiment, but Nerf blasters are generally worth too much for this use, and the parts would very likely break more easily with water. But the aluminum AT2k tank is key here. We need those pull valves too, and if they can be built with 1/2" or 3/4" NPT threads (one side for the pressure, other side for nozzle), then all the better!

Rigging up the trigger is still another matter though, but I'm guessing it'll be easier than rigging up a ball valve. Hmm, perhaps we're still better off with custom parts built to fit Larami shells.

[soakinader]

I'm still playing with the idea of making a pull valve for homemade, rather than any of the ball valves I have found. Until I can find a ball valve that is cheap, easy to turn, and modifiable (add a spring/modify the handle) I am going to be looking at alternate firing methods for any practical weapon.

[marauder]

If cost weren't a factor, what would you use? A pull valve or a ball valve?

[HBWW]

Difficult to say because I haven't handled either in a configuration where cost truly weren't a factor. I would prefer ball valves, but they do require more effort in mechanism and trigger design to open, and probably require multi-finger triggers. (I've hardly used the HydroCannon, so I'm not completely sure on it.) To be honest, if cost REALLY was not a factor, I'd probably investigate pressure and/or electric-assisted valve opening methods, with a simple tactile trigger switch. A return spring may not even be required, if the valve can be hooked to a high-torque step motor. It would simply have to rotate in steps of 90 degrees to open or close.

Of course, at that point, you might as well use electric or pressure assisted blasting itself, if cost really was not a factor.

So practically speaking, I'd probably prefer the HydroCannon's style of trigger and valve. However, Larami really mastered the pull valve in the CPS days, and managed to work around any issues with lamination or flow while doing that. Still, I can't help but wonder how a CPS 2000 would perform with a ball valve. (Although a 2000/HydroCannon integration would be so cumbersome that I'd never bother with it.)