Project something

Building or modifying BB, Airsoft, and Pellet type of guns. Show off your custom designs, find tips and other discussion. Target practice only!
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farcticox1
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Sat Aug 01, 2020 7:14 pm

Got the semi auto together enough to test fire, it seems to work, no magazine tube yet. The chamber and 1/2" valve are from my old 10mm ball bearing launcher so the air supply is probably over kill. The piston is from an old pneumatic cylinder that is cut down. The red block is aluminium.

The principle
piston.jpg
piston.jpg (11.86 KiB) Viewed 5979 times
Part way through drilling the block
piston (2).jpg
03 (1).jpg
Bolt on the side is a stopper with rubber tip to stop BBs rolling out
03 (2).jpg
KannonKing
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Tue Aug 04, 2020 11:26 am

that's a beauty! Can't wait to see it in action!
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farcticox1
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Fri Aug 14, 2020 7:29 pm

After some experiments with piston length and springs I finally got it working reliably. Needed a heavy spring to stop the piston slamming forward too hard, it was breaking the light springs and had started to push the barrel forward 😯 magazine tube holds 30 and feeds 1 at a time consistently.
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farcticox1
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Thu Aug 20, 2020 6:01 pm

Was building the block into one of my old QEV builds which will look much better, after a bit of test firing it stopped loading, took it apart and the piston feel into pieces :( going to make a solid stainless one now, probably needs some bleed holes so the action is not so violent as well. More experimenting :D
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farcticox1
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Sun Aug 23, 2020 3:06 pm

Made new piston from long 6mm bolt with head cut off and piece of 10mm thick nylon, works really good. Semi auto is now built in to my old single shot.
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hectmarr
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Mon Aug 24, 2020 5:15 pm

farcticox1 wrote:
Sun Aug 23, 2020 3:06 pm
Made new piston from long 6mm bolt with head cut off and piece of 10mm thick nylon, works really good. Semi auto is now built in to my old single shot.
20200822_190607.jpg
20200822_192524.jpg
In good time!! I like the general concept and it seems quite feasible that a hobbyist with few tools could build it. Waiting for your video. :)
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