Electro-pneumatic BB machine gun video

[Innovator]

So the barrel is forced/accelerated backwards trough the coil, closes the breech and hits the valve in the back of the loading-mech?

Correct!

Do you drill out this piece from the top after soldering it together?

Yes, and you better be careful while doing it!

Is there a spring in the back of the valve (in the elbow) keeping it closed, or does it close from pressure?

Just pressure.

Why is the gun still shooting a few shots even though you already removed your finger from the trigger? Is it because the motor is still turning from inertia?

Yes it is due to the rotating mass of the motor, aka inertia.

If that is so and if you don't like that, you can maybe avoid that by having the solenoid in the same circuit as the motor, so the solenoid would not be able to work after you stopped pushing the trigger.
Just a thought.

That would, in this specific design, jam the BB feeder. If you feel the need to remedy this non-distinctive ending you can modify the trigger system so that it short circuits the motor when the trigger is released to momentarily stop the motors rotation. I like to think about it in terms of that there is room for improvement and customization!

I wish you good luck with the sale of your plans!

Thanks!

[jackssmirkingrevenge]

Never figured there was a coil involved, good stuff!

Really appreciated your sharing of the mechanism, most people who want to make money off their designs are (justifiably, I suppose) quite secretive about them which makes business sense but it completely goes against the spirit of this forum.

I like to think about it in terms of that there is room for improvement and customization!

While ingenious and clearly functional, I think the design can be greatly simplified, mainly by eliminating the rotary motor and using the movement of the barrel to both reload the projectile and open the valve.



One thing, what's the capacitor for? Is it in the motor circuit?

[Innovator]

I have been experimenting with a simpler setup as well.
Ironically, the simpler version had long time reliability issues.
Different parts of the BB feeder system were dented by handling the BBs at elevated speeds (barrel striking back and forth).
Never the less, I admire you for your great creativity and your persistent chase for the Holy Grail of simplicity. As always, less is more.

[jackssmirkingrevenge]

I have been experimenting with a simpler setup as well.
Ironically, the simpler version had long time reliability issues.

Sadly arriving at the simple solution isn't usually so simple

Never the less, I admire you for your great creativity and your persistent chase for the Holy Grail of simplicity. As always, less is more.

I try Don't get me wrong, if someone can make an automatic spudgun governed by a difference engine I would be impressed and applaud the effort, and I do appreciate seeing a complex and intricate system function well.

When I present a design here however, I would much rather the response be "clucking bell, I'm making one of those tomorrow!" as opposed to "clucking bell, I wish I had the resources to make something like that."

[Innovator]

I totally agree!
However, the compressed air MG is designed with DIY-ability as priority no1. The only "exotic" materials needed are the nylon worm gears that comes with the book. The simplified version on the other hand needed a very-difficult-to-find barrel made of high quality stainless steel, which actually lowered the projects DIY-abaility.
The most exotic tools in the build are a drill on a stand, or better, a drill press, soft soldering equipment and a router. You can do whitout the router, even if the result does looks less pretty. The only special resource you really need is the know-how!