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Variable pump coaxial

Posted: Sat Mar 08, 2014 3:06 am
by dajoro
I present to you all a simple .30 caliber coaxial piston gun with floating o-ring pump and "custom" trigger. My intent with building any air gun is it must be self contained , no co2 or fridge pump. I learned so much here but noticed the lack of pump guns on the files similar to a crossman pistol I've had for years . I do have a very simple trigger system and grip planned out but right now this shoots incredibly well so im showing it !
top view
top view

Re: Variable pump coaxial

Posted: Sat Mar 08, 2014 8:56 am
by Gun Freak
Looks cool, what kind of pressure can you generate? By the looks of it I would guess 200 psi max...

Re: Variable pump coaxial

Posted: Sat Mar 08, 2014 9:56 am
by Gippeto
Clever. :)

Wondering where you found the barrel and how you attached it?

Maybe add a butt of sorts to the pump rod ....

Re: Variable pump coaxial

Posted: Sat Mar 08, 2014 10:04 am
by bravootome
it looks...nice
if you manage to put 30 bar....it will be perfect !

Re: Variable pump coaxial

Posted: Sat Mar 08, 2014 2:32 pm
by dajoro
apologies for phone photos
apologies for phone photos
Thanks , it takes seven pumps to hit 120 psi. and is very impressive at 10 yards.
30 bar would be overkill in my backyard!
The barrel is brakeline . I just took some 30 cal. slingshot ammo to the auto store , can't remember
the exact size.
Its all high quality epoxy inside , the barrel has about an inch long plug. The pump tube is simply
another inch of epoxy with a tiny hole drilled thru and a silicone (or rubber ) flap screwed on.
Ah, and the pilot trigger is as simple as an o-ring on a gold construction screw poked thru brass end cap
that was drilled out larger than the screw , allowing pilot venting.

Re: Variable pump coaxial

Posted: Sat Mar 08, 2014 8:13 pm
by jackssmirkingrevenge
dajoro wrote:Its all high quality epoxy inside
Image

Fantastic work, great to see some out-of-the-box thinking and fabrication :D

Re: Variable pump coaxial

Posted: Sat Mar 08, 2014 9:38 pm
by dajoro
Ha! Thanks jsr , Im always outside-the-box due to being a cheapo ( resourceful ?)
Here's the whole series of pumpers ive got currently. All are coax self contained and fully servicable Both long gun are yes , shrouded mufflers. A 50 cal. and two .25 caliber experiments .

Re: Variable pump coaxial

Posted: Sun Mar 09, 2014 6:46 am
by jackssmirkingrevenge
Im always outside-the-box due to being a cheapo ( resourceful ?)


This is genuinely almost bringing a tear to my eye, those epoxy endcaps! *sigh*
shrouded mufflers
[suppresses integrally]

I'm really liking the self-contained nature of these creations, it would be a great concept for a cane gun!

For some reason I'm reminded of clide's mini-pump, though the latter being coaxial was more compact.

Re: Variable pump coaxial

Posted: Mon Mar 10, 2014 12:39 am
by dajoro
Wow , those were confusing me for a second ! Very different design.

Re: Variable pump coaxial

Posted: Wed Mar 12, 2014 5:45 am
by jackssmirkingrevenge
The execution is different but the concept of a self-contained coaxial is there. Great stuff!