Single shot BBMG

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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evilvet
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Tue Dec 07, 2010 6:32 am

So not really a MG as such but....

I have been trying to come up with a single shot variant, 50 rps is all very well but ammo doesn't grow on trees.

My idea is to have a horizontal spring load mag holding say 20 bb's. This has a push solenoid mounted below it that when triggered will push one round up into the breech block to be fired. The trigger is a simple DPST momentary contact switch that fires both the solenoid and the valve for the air flow. As long as you hold down the button the air flow will run but only a single round can fire as the plunger is blocking the BB feed.To fire again release and press the trigger. Power comes from a 12vdc SLA in the stock.

I have a picture to show this but am too thick to work out how to attach it to the post.

Any comments appreciated
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jackssmirkingrevenge
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Tue Dec 07, 2010 6:45 am

Have you tried adding a restriction (eg o-ring in a threaded fitting) at the breech?
hectmarr wrote:You have to make many weapons, because this field is long and short life
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more_eggs
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Tue Dec 07, 2010 7:01 am

I have been trying to come up with a single shot variant, 50 rps is all very well but ammo doesn't grow on trees.
Funny you should say that.. Iv been shooting these little 6mm gumnuts off the tree infront of my house :P endless supply of ammo!
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Gaderelguitarist
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Tue Dec 07, 2010 10:39 am

Have you built this, or is this still in the design phase?
so many muchness
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evilvet
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Thu Dec 09, 2010 11:55 pm

Gaderelguitarist wrote:Have you built this, or is this still in the design phase?
Hi

Just the design phase but work has finally stopped interfering with what i want to be doing so I will run some samples through the CNC machine tonight to get a feel for the layout.

I managed to get into Jaycar today and picked up the push solenoid, battery and trigger switch I needed so I will do some MDF mock ups of the lower receiver and work out where the parts will fit.

Hopefully the JPG will explain it a bit more. Sorry for the rubbish image but my CAD program does a bad job of DXF to JPG
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lower receiver with internals.jpg
lower receiver with internals.jpg (11.57 KiB) Viewed 2572 times
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Gaderelguitarist
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Fri Dec 10, 2010 12:35 am

Ok, This is similar in concept to using an air ram semi setup, except that you're going electrical. By all accounts, it should work perfectly, provided the parts are machined well. It looks like you're planning on running it on a remote line to a firing chamber in the stock, with the valve being positioned directly after where the solenoid pops the round up.

I look forward to seeing your progress with this.
so many muchness
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evilvet
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Sun Dec 12, 2010 1:36 am

Hi all

Did the basic electronics build today.
Video is at

The eStop is overkill but I do love big red buttons on gadgets. The LED's were salvaged from a photocopier readout as was the trigger switch.

Everything gets housed in the stock plus the 12v battery to drive it.Hopefully I can get started on the stock tomorrow.

Cheers
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jackssmirkingrevenge
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Sun Dec 12, 2010 1:51 am

[youtube][/youtube]

Nice, looks like it will work well. Have you thought of including a timer that might give you controlled bursts or an auto fire option at a fixed limited rate?
hectmarr wrote:You have to make many weapons, because this field is long and short life
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evilvet
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Sun Dec 12, 2010 3:08 am

Hi JSR

Thanks for fixing the embedded link.

If you recall my original post on the electric BBMG, some sort of 555 timer circuit was (and is) always lurking in the back of my mind.

What I would like to finish with is a photo transistor at the muzzle that counts rounds and compares it to a selective fire switch on the stock.

Dial and smile.

Some day.......................................
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POLAND_SPUD
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Sun Dec 12, 2010 7:21 am

Damn I missed this thread...
A 3 way valve + air cylinder would be enough...
if you use a hop-up unit + a magazine from an airsoft gun you don't even need an air cylinder
Children are the future

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Gaderelguitarist
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Sun Dec 12, 2010 11:09 am

The eStop is overkill but I do love big red buttons on gadgets
Why not a key start? You could mount it in the bottom of the grip. I mean as long as you're going for the cool factor.

However you do it, I think it would be great to have a switchable full auto firing mode.
so many muchness
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evilvet
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Mon Dec 13, 2010 12:04 am

Hi all

Making progress

The prototype for the receiver is taking shape, just using MDF for now, the final job will be a series of mm plates of black HDPE. The laminated idea is simply so I dont have to bore and align magazine feeds and barrel housing for the upper receiver; I just make them in mirror halves then bolt it all together. Makes it easier for upgrades and maintenance as well.


The next step is to make two more half shells, this time only pocketed for the equipment rather than cut all the way through.

Cheers
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Starting to work
Starting to work
Test fit
Test fit
A bit of CNC
A bit of CNC
A bit of CAD/CAM
A bit of CAD/CAM
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Patto
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Mon Dec 13, 2010 12:25 am

Looking cool man, i hope it all works out for you !!
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Gaderelguitarist
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Mon Dec 13, 2010 1:48 am

Man, I wish I had a CNC Router. This is going to look really slick.
so many muchness
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evilvet
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Mon Dec 13, 2010 1:58 am

Gaderelguitarist wrote:Man, I wish I had a CNC Router. This is going to look really slick.
Why not build one, I did :P

Not being able to get the right parts for the BBMG was the whole rationale for it.

http://www.spudfiles.com/forums/electro ... rt,15.html
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