AEP/AEG M1 Carbine

[brownien]

I know I've been talking about this concept since the beginning of my membership here, I have finally gotten around to constructing one!

I am using the CYMA springer M1 Carbine as my base gun, and using a JG Scorpion internals. The CYMA is actually pretty good for a springer rifle, and I will most likely get another to suppliment my loaner kits.
The whole idea is to use the CYMA gun as a shell to throw the Scorpion gearbox in. It seems like it will work, and so far with the springer mech gutted, there is plenty of room for the AEP gearbox.
The only problem is, the Scorpion gearbox's nozzle is on the lower side of the piston, rather than the top, which would be ideal. If it was on the top, there would be no need to modify the plastic receiver to sit higher, but I really dont want to do that. I want to keep the lines of the original gun the same. To do this, I will need to manufacture a custom nozzle that is in a Z pattern. This would allow me to offset the gearbox to where the original barrel/hopup is. Also this would allow me to use the original bolt cover, unmodified, to cover the gearbox and hop unit from the top, and be able to slide it back to adjust the hopup.

I was originally thinking of making a section made of metal, for the middle of the Z nozzle and sticking it al together, but with the forces at work durring firing, I feel that it would fail easily. This leaves me to either make one entirely out of copper pipe of the correct diameter, or have a machine shop manufacture one for me. knowing the "inefficient" manner the local machine shop works for my small "side jobs", I think i will have to make a copper one myself. Shouldn't be too difficult. It will just be difficult getting the correct measurements, and getting things to line up.

So far, it doesn't seem to be a hard build, but it has much different challenges than what goes on in a M14/M1 Garand conversion. Only time will tell if I am able to make and sell these, or if this is simply a one off build.

[volkssturm]

Sounds possible. Let us know how it works out.

[2nd Bat]

Indeed we all look forward to updates and progress and wish you well.

[brownien]

I managed to make the Z piece out of copper pipe and sweat it all together, but it is slightly out of alignment, so it wont reciprocate properly. I may have to bend or make a new piece that fits better. Just a quick update, Ill try to get photos up next time.

[brownien]

With my brother's grad party coming up, I have had little time to work on my Carbine build. I have been busy cleaning out the garage and the like, to get ready. I did manage to fit the gearbox, and barrel assembly, along with the new nozzle.
The nozzle is fit snugly in the gearbox, shimmed with electrical tape, and there are no air leaks there! The issue with reciprocation, is the small arm on the side of the nozzle isn't long enough to mesh with the tappet plate at high ROF. I will just have to heat it up and pull out more of the peg. I am having trouble with the Gearbox and hopup lining up properly. I'm not sure if its because the gearbox is askew or if the nozzle is bent slightly.



here's the top view. You can see that the gearbox fits snugly under the faux bolt, which still moves, but the hopup unit is too tall to fit, so I will notch out the front of the bolt to fit the hop unit, like I have alreday started.


In this hsot, you can see the wiring, which will be routed forward, and the battery will be housed under the barrel, in the foregrip. The nozzle fits very good in the hopup, and creates a good seal, but its slightly thinner than the old hopup, not sure if that will be a problem though.

What worries me about future builds, is the complicated shape of the nozzle. I would like to get the correct shape that works, and simply make a casting that I can either pour metal or high strength plastic duplicates. I'm just not sure a casting can be done.
Secondly, if I do manage to get a casting to work, and I get multiple identical nozzles, the fit of the gearboxes in the gun and their alignment with the hopup may not be easily duplicated from gun to gun.

As soon as I make more process, I will be posting it up! I hope to get it firing test shots very soon, but that all depends on if the nozzle and all the alignments cooperate!

[CharleyNovember]

Plastic prototyper?If you can come up with a CAD design there are a few places that can do it for you for a reasonable price. Interested if the Zshape reduces your velocity though.

[2nd Bat]

I too am following this closely with the hope that you can come up with a build process that will allow you to build and market these at a market viable price. Since you're routing the wiring with the intent of placing the battery in the foregrip of the stock how tough do you anticipate swapping batteries will be? I always thought using a carbine stock pouch would be the best approach and routing the wiring back to a battery inside the pouch?

The CYMA springer stock looks pretty good incidently! No matter how this all comes out, thanks for taking it on and sharing your progress. These things always seem easier then they ultimately end up being and I appreciate your tenacity and stick- to -it-ness.

[brownien]

I have been trying to fix the alignment of the homemade nozzle for awhile with no improvements. I can't get the system to feed, or fire without jamming up. For awhile I just felt like scrapping the whole build, and was regretting tearing apart the springer. Now, after taking apart one of my M1 Garands for cleaning, and comparing gearbox sizes, I am thinking of going back to my original build plan of making my own wood stock, and using a Ver. 7 gearbox. The only expansion of dimensions needed, would be just below the reciever, where the trigger is. I could use the springer stock as a template to make my own. I thought about simply adding on to the bottom of the springer stock so the gearbox would fit, but I would rather go with wood, so the overall gun looks much nicer. So I will be going with, using a Socom M14's internals and fitting them into a homemade wood stock.

This means that there will be a greater lag time between when I can sell off my Skorpion Aep and when I can pick up a Socom M14. Hopefully I can find a buyer at the local event I'm hosting!

I really wished the springer conversion would have worked, but I think using a M14 for internals, and not messing with alignments will be much more reliable.

[2nd Bat]

There is a hokey new (plastic gearbox) carbine out that looks atrocious on the outside but might serve as mechanicals that could be used in a converted actual carbine or a stock of your own design. I ordered one of these bastardizations from ebay and will let you know just how bad it is.

[brownien]

Lol! I saw that thread and immediately dismissed it as way too hokey! I don't mind some dimensional stretches for preformance increases, but thats just rediculous! I would imagine it has a plastic gearbox. I'm hoping, by using a Ver.7 gearbox, mine will be as skirmishable as one of the Garands, all while being as compact as the RS for use with my RTO Impression.
I do see a problem right away with using an M14. The magwell being too long will have to be overcome by shortening, and then adding an extention to link the mag feed nipple to the hopup. I also thought to add a small bump inside the feed nipple, so that BB's fed from the mag can enter the extension tube, and when the mag is removed, the BB's inside the gun will stay inside until a fresh mag is inserted. This would prevent 10+ BB's from falling out every mag change, and more BB's per mag would be fired. Downside would be that there would always be BB's stuck in the gun unless inverted and fired out, which isn't a big deal to me, I always treat my guns as hot and loaded anyway.
Mag-wise, I could put those terrible feeding Kingarms M14 mags to use! Just one cut vertically, and one more horizontally, along with trimming the spring, and adding a rear/floorplate, and I will have tons of Mid/Lowcaps for my carbine!

The real question is, why didn't I think of this SOONER!?!

[brownien]

After looking over some things, and pondering quite much, I actually stumbled onto something with the M1a1 Carbine.
Because I am switching over to using a Ver7 gearbox for my carbine, and using a homemade stock, the same gearbox cannot be used to make the M1a1 Model carbine, as was the case with the smaller AEP gearbox.
But after laying the springer carbine next to my Ak74u, and after looking at some photos, I believe that the Ver3 Gearbox could possibly work in an M1a1 Carbine. The -A1's pistol grip, is almost vertical, when compared with the motor housing of the Ver3, but the Ver3 also has an extension off the rear of the gearbox where the spring guide is. This leads me to believe that the Ver3 could possibly be fit into the M1a1 with only a stretch of the pistol grip's dimensions of about 1/4" either way.









Some photo proof

[2nd Bat]

The gearbox in the hokey carbine AEG is indeed plastic and its performance marginal. 230 FPS with .20 grams perhaps 60 feet of functional skirmish range. Obviously it shoots further but not with enough enertia for someone to likely feel it. The gear box is shaped okay to go in a proper carbine stock but too thick. A custom wood stock would have to be made. With the poor performance not worth the effort.

The m14 gearbox is probably the best way to go but as with all these projects feeding consistency is the biggest of many challenges. Keep at it. We're all pulling for you.

[brownien]

Anyone have any ideas as to shorten a Ver7 gearbox? I know I could cut everything down to the proper length, and get everything to work, its just sticking it back together. The cut would be where the cylinder is. I was thinking drilling and tapping the sides to accept two metal plates, to hold and reinforce the joint. I just worry about the gearbox cracking at the screw locations.