Mulit Shot AEG Concept

[renegadecow]

So I was thinking of making a Protecta aka Armsel Striker shotgun (or an AA-12 too since it also applies, same with Saiga 12) and thought of a way to get a 3 shot pattern on an AEG. Other than fabricating a proprietary tri-nozzle/hop/barrel system, how about a simpler 3 studs on a sector gear to engage the tappet plate? The tappet plate will need to be shortened in height so it disengages early enough to chamber a bb and while the lips on the hop up rubber will remain to keep them from going back out, the actual hop nub and window will have to be relocated 3 bbs length forward. What I'd like to discuss is if this is even viable? Or has anyone tried it/heard of it being done in the past? Given a very slow 600-700rpm (10-12rps) and a good quality magazine, I'm thinking it shouldn't pose a problem with feeding at all since guns exist at the 30-50rps range which has the tappet plate and nozzle moving at even higher frequencies. Of course there's still the problem of power suddenly jumping should fewer than 3 bbs are chambered, but if it's feeding ok then it should only happen at the end upon emptying a mag.

[Wingmann]

Interesting idea, although tricky to implement. In many cases the tappet/nozzle length interaction makes single shots tricky, not to say about doing that interaction three times, but it's very interesting.

[ED-SKaR]

entirely plausible. We already have the "dual sector gear" with two notches for the nozzle and two sets of sectord teeth for the piston so that it fires two separate shots on one rotation. I wouldn't know if there is room for three nozzle pegs but you can give it a go! can't be to hard to glue on a couple bits of plastic to the gear as a proof of concept before bringing out proper tools.

 

What you can do is cut a new hop window 12mm(Two BBs lenght, NOT three!) further forward than the existing one, seal up the existing one and use two hop rubbers, cut in the right way, one to seal against the nozzle, and the other in the hop window to give hop to all three BBs.

As with any single-barrel-multi-shot airsoftgun you will get different hop on each BB giving you an up-down spread (Probably why TM went with the tri-shot system) You'll just have to make it and see, but nobody has ever complained about that with the maruzen shell ejectors that have up to 10BBs with one barrel.

 

The power hike is a serious problem, you DON'T need three times the power( IE a 3j gun is to much for 3x1j shots) but you still do need a lot of power, even at 300fps(x3) the power you'd get if it only loaded one BB would be very nasty in a CQB distance.

 

 

This is probably the best idea for practically building an AEG shotgun I've ever heard, I await your results.

[renegadecow]

My sites limit is 430fps for CQB, about 1.7J bringing a tri-shot using .20g bbs at about 250fps which is still respectable. As a safety option, though I'm not sure if I can implement this myself, it could be possible to put in some kind of optical sensor in the barrel which will disable the weapon from firing should less than 3 bbs become chambered. This would then need some kind of override switch to load it back up again permitting it to fire as usual. But that involves electronic wizzardry of which I am least capable of addressing, but it's worth to say all the same in case someone else might be interested. I'll need to test the system first of course which will not necessarily be pinned to any time table. But it's something simple enough to do in increments and if I use a relatively common V2/3 gearboxed gun, won't be expensive either. I'll just need a new sector gear, perhaps a whole helical set while I'm at it as that will help bring rof down, hop chamber, tappet plate and a couple hop rubbers to kill. Testbed, I dunno. I have my PP19-01 Vityaz as having the only V3 so I guess that will have to do unless I get a 2nd hand AK for turning into a Saiga. Although I'm not entirely sure what auto shotgun I'll want to be doing. 

[ED-SKaR]

430 for cqb... Remind me never to play in the Philippines...

 

It would be more practical to have a light gate in the feed tube, rather than the barrel. As you would need a clear section for the light gate to be able to actually shine light into and that'd be difficult. The electronics are fairly simple for the system, but It's not my area either.

[Crimson]

Someone made an AA12 Striker from the auto shell ejecting maruzen, all he did was put the maruzen into the body of a striker

 

 

Edit:

Pictures:

 

[renegadecow]

Aren't those pics from a solid resin cast? I know people have been making AA12 non-firing replicas over at TheRPF. Was exploring using an M1100 last year but was told it wasn't possible to make it fire full auto so I never gave it a second thought.

 

430 for cqb... Remind me never to play in the Philippines...

Few actually go for the limit though. Average you'd see between 300-350 out of sheer decency since everybody there knows each other. Some cases like for my sniper pistols the marshals allow a higher limit.

[Sidewinder-forge]

I have one of those castings from that guy (excellent quality), they are slush cast resin with a foam core so can be cut in half and hollowed out fairly easily.  I intend to make a usable airsoft out of it (no shell ejecting malarky) but have yet to decide how.  I do fancy a multi (tri?) shot arrangement to emulate a shotgun maybe by an AEG/tri shot lash up.or multi-hop/mag set up.

 

If all else fails i'll just end up with a standard setup making it just another AEG in a pretty shell but at least it'll be a working airsoft that looks like an AA12.

 

SAS

[Crimson]

Aren't those pics from a solid resin cast? I know people have been making AA12 non-firing replicas over at TheRPF. Was exploring using an M1100 last year but was told it wasn't possible to make it fire full auto so I never gave it a second thought.

 

Few actually go for the limit though. Average you'd see between 300-350 out of sheer decency since everybody there knows each other. Some cases like for my sniper pistols the marshals allow a higher limit.

 

 

No like the guy above said they are hollow you just scoop out the foam,

 

The M1100 is semi automatic it fires every time you pull the trigger, it would be pointless full auto as you would empty it in a second and it would be useless for skirmishing.

 

Since the AA12 is so big you could use a gas bottle in the stock 3 barrels and a construct a c02 paintball like system to fire the bbs rather easily like a sun project NBB 

 

if i had the time i would make one i had the idea after watching the expendables a few years ago      

[renegadecow]

Could you link the build page? Been trawling the net and all I get is a CO2 GBB "FA-12" which was never finished, a bunch of non-firing resin casts, half a dozen attempts (AEG and GBB alike) that never flew, and Evike trying to fish for likes on Facebook.

 

edit:

Also found a thread from 2009 where the 3 sector gear nub was suggested, but nobody really bothered trying it out. People dismissed the idea thinking that the bbs will not feed as the tappet plate never moves forward enough to chamber a bb as the next nub already gets in the way. That is, with an unmodified tappet plate. My idea is to shorten the tappet plate so it disengages early enough and extend the reach of the nubs to compensate for the shortened tappet plate stroke (caused by cutting it in half). While I'm still ruminating on the concept, I'm already thinking up of the design process for making the AA 12 shell so I guess it's going that way instead of a Protecta.

[hitmanNo2]

I have one of those castings from that guy (excellent quality), they are slush cast resin with a foam core so can be cut in half and hollowed out fairly easily.  I intend to make a usable airsoft out of it (no shell ejecting malarky) but have yet to decide how.  I do fancy a multi (tri?) shot arrangement to emulate a shotgun maybe by an AEG/tri shot lash up.or multi-hop/mag set up.

 

If all else fails i'll just end up with a standard setup making it just another AEG in a pretty shell but at least it'll be a working airsoft that looks like an AA12.

 

SAS

Could you post the contact details for the guy that makes these please? I would be interested in one.

[Crimson]

Could you link the build page? Been trawling the net and all I get is a CO2 GBB "FA-12" which was never finished, a bunch of non-firing resin casts, half a dozen attempts (AEG and GBB alike) that never flew, and Evike trying to fish for likes on Facebook.

 

edit:

Also found a thread from 2009 where the 3 sector gear nub was suggested, but nobody really bothered trying it out. People dismissed the idea thinking that the bbs will not feed as the tappet plate never moves forward enough to chamber a bb as the next nub already gets in the way. That is, with an unmodified tappet plate. My idea is to shorten the tappet plate so it disengages early enough and extend the reach of the nubs to compensate for the shortened tappet plate stroke (caused by cutting it in half). While I'm still ruminating on the concept, I'm already thinking up of the design process for making the AA 12 shell so I guess it's going that way instead of a Protecta.

 

DSGs work i have one you can hit 80rps 

 

you could create a version 3 gearbox and use the pro win hop, this way you get the complete gearbox, hop and barrel unit in one assembly then put in a three round burst mosfet, you would get full auto 3 or 5 round burst but then you dont get the shells effect 

[Sidewinder-forge]

If you had a system where the nozzle split to be come 3 nozzles each one going into a separate hop/barrel with it's own mag feed - that would conceivably work.  Also be one of the simpler mods as the only custom part would be the 1 into 3 nozzle splitter.  Maybe a stronger tappet return spring would be required too.

 

Am I right in thinking If a no-feed occurs in one or two of the barrels then the remaining BBs will be fired with lower FPS as the air will follow path of least resistance down the open barrel(s).

 

SAS

[renegadecow]

@Crimson

That was what I was thinking of last when I had the urge to make a USAS-12, but it just doesn't feel right. The way I see it is if I pull off this tri-burst concept, I'll get the volume of fire of a high rof gun, but not necessarily stress everything to destruction as the crucial bits are happily chugging along at a leisurely pace. Also, if you could please link to the the Maruzen M1100 AA-12 build you were talking about earlier? I know my intentions are to build an AEG, but I'd just like to know if and how that chap you mentioned did it on a GBB.

 

edit:

@Sidewinder-forge

Had thought of that earlier, but the problem with copying TMs tri-shot design is it sort of needs that arm at the bottom that aligns the 3 bbs into the chambers. At first I thought I could just replace that part with a ramped edge at the lowest part of the tri-nozzle, looking like a GBB nozzle loading arm, but the problem is that in mating 3 sections of barrels together its combined outer thickness creates too big a gap causing the 3 to-be-chambered bbs to ride too high causing a 4th bb in line to come up and block the way of the nozzle. In theory this could be sorted out by having the barrels machined so that they have as little space between them as possible making the bbs align naturally, but I think that's an even harder task. 

[renegadecow]

Ok, related to the whole shotgun AEG concept, is the Burst Wizard the only way to reduce rof on an AEG? Kind of a waste with all those features when all I really need is to slow things down. Looking at Ebay, will an LED DC dimmer switch work? I know it works for AC, but unsure if the same holds true for DC. It's rated to 12V 12A. Or will the amperage kill it (using a 9.6V NiMH on a M120-30 spring)?

[Sidewinder-forge]

RC::This is actually what i'm thinking of trying.  V3 gearbox as it's more self contained than a V2 (assuming the motor cage fits in the AA12 body's grip) & AK type Hop as they are slim and flat sided allowing them to sit next to each other easily.

 

 

SAS

[Dr.Arnie]

i was dabling with something like this for another project, i came to the conclusion that the easiest thing would b to canabalise the parts from a tm tri shot system, such as the nozels and feed and go from there. i was thinking of a custom gearbox shel that would use a tri chambered cylinder like the tm's or a large single cylnder with 3 nozels. the magazine would have been a lovely hi cap lol.

 

as for controling the ROF theres a chap on AM thats making  programable fet where you programme it on the pc so that could be the way to go i think.

[ED-SKaR]

For the battery, why not just use a huge low voltage battery, think at least 3Ah, probably a 7.2 nimh if 8.4v is too much.

 

 

For the feeding system of choise, KISS. The three notches on the sector gear is the simplest and most likley to succeed. Making multibarrels and all the other required parts is a lot of work right there.

[Crimson]

The forum in question went bust a year ago so i have no way or any idea who it was that made it.

 

The Dsg idea will work and you just need to slow down the rof, the only thing that gets stressed in the DSG is the motor which sometimes dies on you  

[hitmanNo2]

You would think if someone made a semi auto shell ejecting AA12, they would be whoring it all over the place, YouTube e.t.c.

[Corkie121]

This may be terribly uneducated as I'm by no means an expert on AEGs, but is it not possible to simply move the hop further forwards, so that when the nozzle retracts, 3 bb's roll into the chamber instead of one? 

 

Corkie

[Yuri]

I would think that having a single cylinder firing bbs from three different barrels simultaneously would be terribly inconsistent. There's a reason why the Marui tri-shots have a separate piston and cylinder for each barrel. There's no guarantee that the air would be divided equally among the barrels.

 

For the three peg sector gear idea, the pegs should be placed as close to the outer rim of the gear as possible. This will maximize the amount of nozzle travel that can be had per degree of turn. The pegs should also contact the tappet plate at the apex of the sector gear for the same reason.  

 

As for the ROF control, you can buy DC motor speed controllers that use PWM, which is exactly what those fancy ROF control MCU fets use. There are a bunch on ebay. I have no idea if you can find one that would work for this application but it's something to consider. 

[renegadecow]

Thanks Yuri! Found one rated to 30A 24V.

 

@Corkie121

If you move the hop chamber forwards enough for 3 bbs to fit in, the nozzle will never move forward enough to seal the hop chamber.

 

@Sidewinder-forge

Ok, hooking up the 3 hop chambers to individual feed systems is gonna work. Gonna be a tight squeeze for the barrel since you have to spread those 3 chambers far enough for the middle one to pass through, but it'll work.

 

Regarding that GBB shell ejecting AA-12, I'm with Hitman. Don't get me wrong Crimson, I'd really want to believe you, but in this day and age it's pics or no dice and the ones you posted are only of the non-firing resin prop. It's likely that what you read was an attempt in making one rather than an actual finished and working unit.

[Crimson]

Maybe who knows but i am sure in 2009 i saw a picture of someone who made an aa12 and stuck an shotgun inside it, i think the form was called ukan or something like that.

 

Anyway i think your best bet is to cannibalise  a TM Trishot for the gas system, use a standard paintball set up for the trigger system, your problem would be getting the bbs to reset each time 

 

AEG wise i would go DGS with a 5 round burst option or as crazy as it seams, 3 separate V3 gearboxes stacked on top of each other    

[renegadecow]

Heeey, looks like I found the perfect gearset to mess with. 

http://shop.ehobbyasia.com/shs-low-noise-high-torque-gear-set-for-gearbox-v2-3-100-300-1.html

The 3 screws joining the two parts of the sector gear look conveniently placed to time with the sector gear teeth. Just have to replace the screws with longer ones so the head protrudes acting as nubs engaging the tappet plate.