BFG #7

[farcticox1]

Anybody got any ideas on a fully pneumatic powered semi automatic bolt action set up.

I'm thinking pulling the trigger switches a pilot valve to send air down the barrel, pulling the trigger fully in, shuts of that air and triggers the reload cylinder ( bolt action ) so a secondary actuater on the trigger.

[mobile chernobyl]

Check out the 'Autococker' paintball mechanism:
http://www.zdspb.com/media/tech/animati ... er_wgp.gif

Tons of other paintball based semi-automatic ideas here:
http://www.zdspb.com/tech/misc/animations.html

[keks2033]

Anybody got any ideas on a fully pneumatic powered semi automatic bolt action set up.

I'm thinking pulling the trigger switches a pilot valve to send air down the barrel, pulling the trigger fully in, shuts of that air and triggers the reload cylinder ( bolt action ) so a secondary actuater on the trigger.

simple semi-automatic rifle with a piston valve. Shooting out of it: The piston valve makes it easy to semi-automatic rifles. On my channel there are several of these guns.

[farcticox1]

Worked on the circuit a bit, going to get some parts and make a test set up of this.

Pulling trigger should operate main valve then operate the control valve after a short time set by restrictor, which shuts off main valve and opens breach to load 1 ball. Releasing trigger should reset valves ready to fire again.
On initial loading, before firing, 1st round can be loaded manually as breach cylinder is spring return, just like a real gun.

[farcticox1]

Tried it on Fluid Sim and it seems to work

[Brian the brain]

This was my idea...although it can be set to full auto aswell.
[youtube][/youtube]

[farcticox1]

Made the skeleton for the grip and trigger mechanism

[Kensingt0n]

Nice work farcticox, looks like some clean work dude.
What tools did you use to make that whole mechanism?

[farcticox1]

I have access to a decent drill press at work, apart from that all hand tools. The main plate is 10mm aluminum, it's a bit discolored as it was basically scrap metal left outside.
I have some nice 3/8 thick white nylon to finish the grip, other parts have arrived so lots more to do yet. The barrel is going to be 1/2' OD stainless seamless tubeing, the ID is 10.2mm so the ammo will be 10mm ball bearings.

[cowscankill]

Nice work so far!

Are you planning on making the valves or using premade? That one you have so far looks really slick.

[farcticox1]

Just using off the shelf pilot air valves, I have a 3/8 port for the barrel and a 1/8 port for the pilot.

[farcticox1]

Just playing with layout, this looks interesting, the stock will be the main chamber. So what is a good chamber/barrel volume?

bullpup_zpswoqhd0om.JPG (10.83 KiB) Viewed 6113 times

I have read 4:1, I should be able to achieve that easily.

[Kensingt0n]

I have access to a decent drill press at work, apart from that all hand tools. The main plate is 10mm aluminum, it's a bit discolored as it was basically scrap metal left outside.
I have some nice 3/8 thick white nylon to finish the grip, other parts have arrived so lots more to do yet. The barrel is going to be 1/2' OD stainless seamless tubeing, the ID is 10.2mm so the ammo will be 10mm ball bearings.

Great craftsmanship mate, love how accomplished you feel when you achieve results like that.
Man, that ammo should chop anything it touches
Sorry if you had already stated, but what were you planning on using as your chamber?

[farcticox1]

I might fabricate it from stainless sheet if I need to get the volume, have Tig welder as well, or use tubing, haven't got that far yet.

Converted my main valve pilot to side entry pilot, found a nice 1/8' flush plug to fill the original hole, new hole is M5

[Kensingt0n]

Damn man, that's a mad idea for your pilot valve.
I really need to get some more tools myself, or just find a new job haha.