32 replies to this topic

[NerfFreak]

Here's my design for the Frequent Assault Massive Action Shitlauncher (FAMAS). I scribbled it down in paint to show everyone, so it may not be 100% complete, but the basic idea is there.



I believe my design tinkers with something new. The bolt and the barrel are one piece. The barrel moevs backwards, pushing back the plunger to the catch (not shown), and also allows the breech, which is the hole shown with a red line on the brass, to recieve a new dart. Then the barrel/bolt is moved forward into firing position. Behind the opening of the breech will be some sort of bolt piece to keep the dart moving forward, not backwards, in the barrel. The large blue piece around the breech opening is the sheath, to keep the breech covered when a dart is chambered. Prototyping begins tonight. Any questions?

[GeneralPrimevil]

Reminds me of a manually-operated version of half of a Barrett M82 action. Barrel moves back to assist in unlocking the bolt...


Not bad in concept. One thing I'd recommend including is how the 'sheath' around your breech opening be extended to the rearmost of the magazine well. That allows a minimization of dead space in your cylinder. Also, to minimize dead space behind your dart in your barrel, have the breech opening as close as safely possible to the end of the barrel. Another thing is perhaps some way of locking your barrel forward to prevent any mishaps or unnecessary damage to your barrel's breech end.

I'm assuming the reason you opted to use a slit in the bottom of your barrel instead of the end of the brass tube is to prevent misfeeding from any damage that may incur on the barrel's end due to the pressure against the plunger/piston-spring assembly. I'm also assuming your magazine won't be curved, unless I missed something in homemade magazine technique during the past year or so I've been gone


I guess not bad. I still prefer pneumatic devices due to less moving mass...but that's personal preference. For a simple multi-shot spring launcher it has potential on paper. Let's see how your prototyping goes.


If this is going to be based visually of of the real FAMAS, you could very easily integrate a sort of slide-mechanism to make this thing pump-action

[NerfFreak]

What I forgot to mention was that the feed lips on the magazine lock around the barrel/bolt, so the barrel/bolts slides within it, making it more stable.

I've already got parts of the barrel done, the main reciever cut, and a few other parts. I hope I can get it done soon.

[Prometheus]

Reminds me of a manually-operated version of half of a Barrett M82 action. Barrel moves back to assist in unlocking the bolt...


Not bad in concept. One thing I'd recommend including is how the 'sheath' around your breech opening be extended to the rearmost of the magazine well. That allows a minimization of dead space in your cylinder. Also, to minimize dead space behind your dart in your barrel, have the breech opening as close as safely possible to the end of the barrel. Another thing is perhaps some way of locking your barrel forward to prevent any mishaps or unnecessary damage to your barrel's breech end.

I'm assuming the reason you opted to use a slit in the bottom of your barrel instead of the end of the brass tube is to prevent misfeeding from any damage that may incur on the barrel's end due to the pressure against the plunger/piston-spring assembly. I'm also assuming your magazine won't be curved, unless I missed something in homemade magazine technique during the past year or so I've been gone


I guess not bad. I still prefer pneumatic devices due to less moving mass...but that's personal preference. For a simple multi-shot spring launcher it has potential on paper. Let's see how your prototyping goes.


If this is going to be based visually of of the real FAMAS, you could very easily integrate a sort of slide-mechanism to make this thing pump-action

God Damn. Though you were dead...

FAMAS, where have I heard that before.... Fuck you bad memory, it's from some other innovative design.

Anyways, cool design. GeneralPrimevil summed up what I have to say, but I'd like to reinforce the removing the dead space thing. It'll make a huge difference in range and power.


EDIT: Found it. French bull-pup design, awesome gun.

Edited by Prometheus, 16 October 2007 - 08:14 PM.

[NerfFreak]

The FAMAS was what this gun was based on, which is why I incorporated the bolt handle to be on top rather than on the sides.

Primevils right, this could be pump action, but I prefer bolt action, just because I'm a traditionalist to the weapons I base my designs off of.

The main problem I'm seeing is getting everything to line up correctly. Lots of precision measurements are up ahead, so let's hope I don't screw it up.

[Zaxbys]

The FAMAS is a real gun, so thast probably where you have heard it from Prometheus. Heres a picture of a FAMAS:

[keef]

So the whole stock is the plunger?

[Chanclas]

The bolt/barrel idea is not new.

Ompas scar-n

Boltsniper's NTS

To get a dart through that long ass barrel and get decent range you'll have to use the entire stock for the plunger. But it looks like a good enough desing to work.

Edited by Chanclas, 16 October 2007 - 08:22 PM.

[NerfFreak]

Yeah. There will be more on the rear of the body to compose the rest of the stock, and make it more comfortable.

[Chanclas]

Oh and you'll need a really long catch to reach from the handle to the plunger.

[Prometheus]

The bolt/barrel idea is not new.

Ompas scar-n

Boltsniper's NTS

To get a dart through that long ass barrel and get decent range you'll have to use the entire stock for the plunger. But it looks like a good enough desing to work.

He was combining that idea with the bull-pup concept. Plus NerfFreak is the kind of guy who follow's through with a design and builds it.

[Spectre666]

I hope you successfully (sp?) make this. I love the FAMAS, it's one of my favorite guns. If this works, I'll seriously buy one from you.

[NerfFreak]

Thanks Prometheus.

Also, Chanclas, look at the NTS part picture again. Notice how Boltsniper labeled the two feeding parts the barrel and bolt, not the barrel/bolt. They're two different pieces. Mines only one.

Spectre: Cool. Cool thing is they'll be cheap and easy to make. Probably only around $15-$25 dollars a gun. Not as much as some people would charge for a SCAR-N or FAR.

But note that this probably won't even be close to available for purchase for quite some time. It has to be built, tested, analyzed, and have it's stage of general warring and shooting until I can find time to build these for the public.

Plus it's school season. Gotta keep the grades up.

Edited by NerfFreak, 16 October 2007 - 08:40 PM.

[Lynx]

SO...the barrel:

locks the plunger,
grabs a dart,
moves back to the front,
locks into position
and makes waffles.

All with a pump action? Sounds delicious!











leggo my eggos

[SHADOW HUNTER ALPHA]

Not bad. A few suggestions, though.

1) Get rid of the crescent-shaped magazine. Those were only designed to hold bottlenecked ammunition, and darts are straight pieces of foam. It will cause feeding problems.

2) I know the diagram is not to scale, but try not to make the barrel excessively long. boltsniper's formula for general barrel length is that the volume of the barrel and plunger tube should be at a 1:4 ratio, respectively.

3) Make sure that the top-mounted charging rod is comfortable. It's not the most convenient position to pull against a spring in, and the thin rod may snap or warp.

4) I only include this because it is not mentioned or shown. The plunger tube needs to have a way to focus all of its air output into the barrel, which means a pipe extending into the back of the barrel, or the back of the barrel directly interfacing with the plunger head and then forming a seal with a piece that isolates the plunger tube (think how an LS bolt is set up for a better explanation).

[Prometheus]

Use an LS mag, it'll be easier to work with due to the feed lips. I'm working on a Solidworks 2007 model of a LS magwell, and I can then take the stereo-lithograph file (.stl) to the 3D printer at my university and get it printed in ABS plastic. I'm hoping that when my personal copy of Solidworks is up and running, I can have it done in less than 1 month (so maybe 5 weeks from now).

[CaptainSlug]

I believe my design tinkers with something new. The bolt and the barrel are one piece.

Newish. It's been done by me and a few others in the past.

One problem I anticipate becoming an engineering problem is also one that can create issues in real bullpup rifles: the need for a long trigger linkage.

Edited by CaptainSlug, 17 October 2007 - 01:48 AM.

[Carbon]

The bolt/barrel idea is not new.

Ompas scar-n

Boltsniper's NTS

Also, Chanclas, look at the NTS part picture again. Notice how Boltsniper labeled the two feeding parts the barrel and bolt, not the barrel/bolt. They're two different pieces. Mines only one.

The two designs are similar, but opposite:

In Bolt's design, the barrel is stationary, and the bolt/breech sheath moves.
In NerfFreak's design, the breech sheath is stationary, and the barrel/bolt moves.

Which is in no way speaking against your design, NerfFreak....just that they share similar concepts. Which means you can probably borrow some design elements.

As far as execution...one thing that may cause you problems is that the plunger will now be slamming into the rear of your barrel, as opposed to the floating bolt/breech cover in Boltsniper's design. Not a big issue, but since your barrel will need reasonably precise alignment in order to keep feeding smoothly, the extra shock may cause you problems, particularly because of the weakening effect your breech hole will have on the entire barrel.

Edited by Carbon, 17 October 2007 - 11:59 AM.

[CaptainSlug]

It will just need a bulkhead piece inbetween the end of the plunger chamber and the barrel/breech. One that will take the impact of the plunger, but also interface the barrel/breech onto the plunger chamber to make a seal.
And it will also need to keep the dart from being pushing into the plunger chamber.

Edited by CaptainSlug, 17 October 2007 - 12:23 PM.

[Quilan Fett]

The problems I see are that
A. It will be huge
B. The barrel might not be strong enough to cock the gun due to the opening.

[kingshane50]

I love the FAMAS, it's one of my favorite guns. If this works, I'll seriously buy one from you.

1. same here
2. pump-action would be better (in my opinion)

[NerfFreak]

As I've said earlier in the thread, I am a traditionalist, and want to keep the guns the same as they are in real life. I also think that bolt action is cooler. Too many people think slapping a pump on a gun is the best thing ever.

[SHADOW HUNTER ALPHA]

Also being a traditionalist (and a perfectionist), I understand your side. However, I just want to caution you that the bolt handle should be a (hardened) steel rod, preferably .25" thick, to withstand the repeated force exerted upon it. I would also coat it with a few layers of craft foam or something similar to keep it more comfortable, just because your finger will have to be drawing back against a powerful spring to cock the gun every time.

[NerfFreak]

To keep it shaped right, I was thinking of layering some 1 1/4" PVC pieces to a certain thickness, gluing them, and sanding them down to the proper shape. The craft foam is a good idea. I'll have to use that.

[CaptainSlug]

Okay, I misunderstood your design before. Now that I understand it I can safely say it's not a great way to go about operating the gun. And you're likely to simply end up shoving darts into the plunger chamber instead of loading them into the barrel.

Edited by CaptainSlug, 17 October 2007 - 10:29 PM.