2 replies to this topic

[Snakuu]

Okay, so I recently picked up an AT3k.

It barely worked stock - sometimes the darts would even clear the barrels. Eventually, I realized that this was due to the pressure in the air tank leaking out whenever the pumping handle was all the way back (towards the trigger guard). Not being terribly familiar with air-powered Nerf guns, I chalked this up as a quirk of the overpressure release system. Afterwards, I managed to get ranges of 5 - 10 feet by just making sure that the pump handle stayed forward as much as possible and pumpoing the gun many, many times (10-15).

I then tried to modify this gun in order to obtain a rapid-fire alternative to my venerable modded Nite Finder. Using Cxwq's PETG barrel-replacement article as a guide, I used hot glue to obstruct the overpressure release valve located at the end of the plunger. Or at least I thought I did. Turns out that the range isn't significantly different, and it still has the problem of depressurizing with the pump handle back. In addition, even with the hot glue in place, it takes 10 pumps or so to acheive a halfway-decent range, even though pumping the gun that much shouldn't even be possible.

I've tried several variations on the "overpressure release valve-plugging" theme, using hot glue to seal every single seam, gap, or other feature on the plunger assembly that could conceivably allow air to escape (including filling in the hollow plunger tube just behind the handle connector), but to no avail. In addition, I've checked all of the hose connections to the air tank and pump assembly and they seem solid enough (although I haven't yet tested them underwater to make sure, primarily since I live in a college dorm and don't have access to a bathtub).

I've searched through the old forum posts and checked Google and Wikipedia, but haven't found references to anything like this. So, has this kind of thing ever happened to anyone else? Any ideas about how to fix it? Thanks.

[NerfMonkey]

That's not your OP valve, it's the check valve. I lost both 3ks the same way. It might have been due to the fact that I did a craptacular job plugging the pump and got a mound of glue on it, so if you have another be careful plugging the pump. If the gun just loses all the air as soon as you pump it that's the check valve and I'm not entirely sure, but I don't think there's a way to fix that other than just replacing the stock pump with a totally different one.

If you plan on doing this, just take some 1/4" outer diameter vinyl tubing and replace the stock 3k tubing with that. Connect it with Plumber's Goop to both the 3k tank and the new pump you're using. You probably won't be able to keep the cool shotgun-esque pump, but it would be a lot better to have a working gun with a new pump in it.

[ompa]

It's more than likely your check valve, from what you're describing. On all the guns I've had the problem on, I've had to replace the whole pump. However, you might try carefully opening the back part of the pump and attempt to "fix" the check valve, possibly by replacing the rubber or looking for anything that might be causing the valve to be stuck.

~ompa