Ak6 Semi-auto mg.

[Gnarp]

Hello guys,

Have made a 6mm semi-auto bb gun:)
It uses a QEV and a 3way NO solenoid for firing and a second solenoid for reloading.
Everything is driven by a arduino nano and two transistors for firing control.
Have also a fire select switch so i can have : safety, single, burst and full auto

The reloading mech are a 6mm pipe inside the barrel that are connected by a rod to the solenoid on top, the pipe have a super good seal to the outside and the magazine) Rely lucky on that one:P
Almost finished just need to put everything together so i can hold it in my hands:P make a stock!

It shoots pretty good and the magazine works like a charm, have noticed one double feed, maybe i will put in a ball dent later on.
Here are some spec:

Pressure: 20-25bar
Velocity : 155m/s@0,88g
240m/s@0,20g
Barrel: 6.01 mm x 600mm
Tank: 1,25L
Magazine : 12 rounds
Closed-bolt

[Gnarp]

And a video, Just a crappy one, the microphone got overwhelmed by the gun:P

[youtube][/youtube]

[Anatine Duo]

neat.... makes me want to learn!

[jackssmirkingrevenge]

[youtube][/youtube]

There is so much potential with modern micro-controllers and it's great to see it exploited, nicely done!

You're getting about 8 ft-lbs/11 joules with what I presume are steel BBs, very respectable! What's the maximum pressure the solenoid can take? Something like a Ninja 13 cubic inch bottle can be adjusted to give an output of 450 psi/30 bar if you want something portable.

I like the silencer on the exhaust port

[Gnarp]

Thank you, yes they are nice to have, they do the things you tell them and nothing more:P haha
Thinking to ad a third switch so the gun stops when the mag are empty! no dry fire.
Yes thats the steel ball att 20 bars, going to test 25 later on.
The valve are rated to 20 bars, if i remember correctly it starts to leak at 30, need to test.
I have everything to make it portable but thats a good advice, have been lurking around ebay on different regulators before:P

Right now i will use my 1,25l tank, but it will just handle maximum 28 bars. got 3 soda stream tanks as well.
I could us them but my valve are my limiting factor, its hard to find a 3 way NO that goes over 20 bars:( they are so convenient to fill and fire:P

But i have been thinking to buy a 75 bar regular solenoid and attach it to the QEV and add a spring on the piston, so then i just use the sodastream on the qev directly .

But have you guys tried with a spring behind the piston on the qev? When i tried the hole tank dumped at 50 bars true the gev when i open the exhaust port! Maybe i need a stronger spring an micro mass of air behind the piston and the exhaust valve?
Maybe the 75bar rated solenoid will have the guts to seal faster than a lower rated solenoid?

If not i will buy 2 solenoids and make my own 3 way, let the mcu control it!

[mark.f]

Ayyyyyyyy.

Always nice to see people using microcontrollers for these kinds of things. Good job!

Thank you, yes they are nice to have, they do the things you tell them and nothing more:P haha

Clearly you've never experienced 4000 series IC's.

[Gnarp]

thanks its awsome to just plug in the gun to the pc and tweak the valves:P

Hehe have not tried them! think i will stick to the atmel chips:P

[jackssmirkingrevenge]

But have you guys tried with a spring behind the piston on the qev? When i tried the hole tank dumped at 50 bars true the gev when i open the exhaust port! Maybe i need a stronger spring an micro mass of air behind the piston and the exhaust valve?

I presumed your three way solenoid is attached to the exhaust port of the QEV, if that is the case then the tank should be shut off at the moment that your exhaust is open to the atmosphere, so how could the main reservoir have been dumped?

Could you post a schematic of how your set-up is connected to help us understand?

[Gnarp]

I just connected a regulator solenoid on the exhaust and a spring on the QEV piston. And the sodastream attached to port A . I can make a diagram later today

[jackssmirkingrevenge]

Since you mentioned it was a 3 way solenoid, I assumed it was connected to the exhaust end of the QEV and when normally open it fed air from the tank into the pilot area and when closed, shut off the air supply and opened the pilot to the atmosphere.

If however you are filling from the chamber side, then since your typical QEV has a parachute type diaphragm/piston seal you need to poke an equalization hole in the side of this seal for it to work.

In this experiment I had machined a delrin disk to replace the piston and added a weak spring which worked for filling from the chamber side, with a pop-off valve pilot for full auto:



[youtube][/youtube]

[Gnarp]

I see, not easy to explain some Times, The first you describe is how my gun works now

Have tried your config but a solenoid istead of the pop-off valve.
Maybe a the pilot volume was to big and the solenoid to weak to seal again, need to experiment again,

BTW i have contacted a valve company and they could maybe deliver a 3way NO 40bar valve that would be insane fps and muzzle energy :p