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Pump up BB gun - New trigger system!

Posted: Sat Aug 23, 2008 7:58 am
by Mitchza89
G'day all, this is my new pump up bb gun. I don't have a gauge but I don't really need one. The pump has a schrader valve as the check valve. It's totally air tight and it would take a serious amount of pressure to blow it out. I usually only pump the gun 15-20 times for a seriously powerful shot.

I came up with this trigger mechanism. I was sick of the slow flow that the ball valve trigger had, so I'm using a modded pop-off pressure relief valve as the pilot. I removed the spring and attatched a sear. The gun is only half done but the idea worked perfectly. I still plan to add a grip and a trigger. This is the fastest pilot release I've ever came up with, it's insane. It's improved the performance 10 fold. I've pumped up this gun as high as I possibly could and It was totally leak proof so I reckon it's good for up to 450-500psi.

PIC TIME!

Posted: Sat Aug 23, 2008 10:05 am
by nivekatoz
Thats cool.. I don't know if you seen my trigger system on my gun but I think you should rig up a finger pull and a handle of some kind..Just so it has the feel of a real rifle. Also a stock..I think that would make your gun look kick a$$!. Could you leave the spring in or is the pop off to low of pressure..if so I think you can buy high pressure pop off or adjustable ones.

Posted: Sat Aug 23, 2008 12:30 pm
by potatoflinger
can you explain in more detail how the trigger works? It sounds like it works really well.

Posted: Sat Aug 23, 2008 12:34 pm
by Tom
I'm having precise the same trigger on my piston valve shotgun :D , except the exhaust valve is homemade. Really nice build, looking forward to the completed version:D

Posted: Sat Aug 23, 2008 7:23 pm
by Mitchza89
Cheers alot guys. I had to mod the pop off valve because after 10 pumps, the valve would start to open and wouldn't let me go any higher. I took the spring out of the pop off valve, and the sear holds the pop off valve closed at any pressure. as soon as you drop that pin out, it instantly releases the pop off valve and dumps the pilot faster then you can say BB :D

Posted: Sun Aug 24, 2008 1:58 pm
by Gippeto
Looks good Mitch! :)

Barrel size is 8mm?

Posted: Sun Aug 24, 2008 6:32 pm
by Mitchza89
Yes mate, it sure is. Ever since I saw the vid of your metal co-ax, I never really thought how much difference you get with releasing your pilot quickly. I mean....yours sounds like a bomb going off at 120psi!

Dispite being 100% functional, the gun looks like crap. I've recycled those fitts hundreds of times over and they are just really starting to show it :(

I'm gonna make my last gun pretty soon. I'm really starting to lose passion for this hobby. I guess the next stage is a hybrid but I'm no machinist so getting something like Larda's is out of the question but... A nice shiny all copper and brass marble blaster with all new fittings (nothing recycled) and a homemade triggered pop-off valve should make me leave on a good note :D

Bah.....shut up Mitch...Enough rambling... :D

Posted: Sun Aug 24, 2008 6:55 pm
by Sticky_Tape
Wow you actually tnk you can quit nice gun.

Posted: Sun Aug 24, 2008 7:01 pm
by Mitchza89
Hmmm I know...The hunger is always there :( haha

Posted: Sun Aug 24, 2008 7:12 pm
by Sticky_Tape
Some times I wonder why I do this stuff.
and then I say ''oh, yeah''.