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Full Autos (K'NEX) Answered

With this link, it should be easy to build a K'NEX automatic. Scroll down to "Blowback Guns" and hold down the trigger.


It isn't possible to make a blowback gun with K'NEX. Because we do not use explosives in guns, so we don't get the recoil. However, it is possible to make a machine gun out of k'nex with THIS DESIGN IN THE VIDEO. It's a basic setup: At first. A large wheel with pins sticking out rotates and pulls back the firing pin. After a while the firing pin will be released, letting the firing pin blow the bullet out of the barrel. If you continue cranking, this proccess will repeat, and there's your fully automatic gun. However, some k'nex guns are powered by firecrackers. But if you would use real bullets the barrel would explode from the extreme force. (Sorry for ultimately long comment :P)

Yeah, because this hasn't been answered or anything... Bit of an old topic, annoying when they keep getting necroposted.

I don't understand why it's annoying.

Because they are old topics no-one cares about anymore.

Still, it's not yours. I care if someone posts a reply.

its the never ending revolver!!!!

There is nothing for knex guns to get the explosion necessary to push the pin back.

Mabey put a rubber band after the pin hits the bullet so it doesn't loose speed but then gets pushed back???

Doesn't work. Try applying some physics. Newtons 3rd (I think) Law: Every action has an equal and opposite reaction. So if the bands on the pin were stronger, the bands to push it back wouldn't be able to outbalance the pin bands, if the push-back bands were stronger the gun wouldn't fire, and if they were balances the pin wouldn't move at all.

if his law is true, then it should work. a full auto knex gun. if we completely held the gun solid in place then the firing pin should bounce back according to his law.

no it wouldn't because the ram would apply say 5 newtons of force, and the rubberband would apply 5 newtons back onto it, but since the ram has more mass, it will force the rubberband back instead, not the other way around.

If the front ones were more powerful and in front of were the pin hits the ammo so It only feels the tension after it fires it might work.

Build it so it works then speak to me whilst holding it. Trust me, it won't.

you read my other comment? NOTE:I was under the efects of 10 energy drinks when I wrote it.

what if you put a spring on each bullet? like, you could use my AR4 and instead of using shells use springs? it will take ALOT' of modding though

there are several ways to make a full auto gun. 1. use a motor to pull and release the ram 2. use a crank to pull and release 3. something I thought of that may work: hold a whole bunch of rubber bands ona spinning white connector, and have a mag that pushes the bullets up fast enough to recieve contact with each rubberband. it could work. REMEMBER!!!!! NUMBER 3 WAS MY IDEA. JUST THOUGHT I'D SAY THAT.

yeah, you're right, i searched some more and saw that it was already used, sorry to anyone who may have been offended by this comment.

Number 3 does work, but as more of a shotgun than a machine gun.

What do you mean by "hold" them? Other than the fact I don't know what you mean, I get it. (?)

ok, you know how you have that little area in any connector that connects to a rod? will in that place, you can put a rubber band and when it rotates, it will release the rubberband.

yeah, wouldn't work, but the gatling gun might.


9 years ago

I've had a lot of inspiration from howstuffworks, but the blowback or gas systems simply don't work in a K'nex gun.

Would not work, you would need an explosion in the barrel (Which cannot be performed in knex guns) To push the bullet forward and the pin back

Bakenbitz's mech is the closest we can get to that.

i think the gatling gun is the easyist to complete.

What would push the bolt back after each shot? Short of fitting explosives, nothing.