Introduction: Full Auto Knex Gun

Picture of Full Auto Knex Gun

So i was looking at myomys full auto theory and thought, he is making this way to complicated. So I added a few changes and used a simple trigger to make the first fully functioning full auto knex gun. It shoots 9 shoots in less than a second but when put in slow mo one my phone, you can see each individual shot being fired. With a little help from the dunkis I declare this the first functioning full auto knex gun. I realize that knexguy123456 or what ever his name is made a full auto knex gun, but his could only hold 2 which doesn't really count IMO. So let's talk about stats.

Full auto
Looks ok
9 shot
Complicated mech
Jams very little
High rof
The rof is so fast that the whole controllable part is useless since it fires so fast but nevertheless is controllable.
Long reload times (about a min)

Firing demo -

Over view of gun-

So I hope you guys enjoy my first innovative knex gun.

Blue mullet - trigger mech off his blowback rifle
The dunkis- helping me figure this thing out
Myomy- for being the first to make a similar mech


Knex Lego Maniac (author)2015-07-09

cut down on cut parts takes the challenge our of the build. Otherwise keep up the ideas

Well Building a full auto knex gun with no broken pieces would be extremely hard. it wasn't easy building one with tons of broken pieces lol. Thanks though, means a lot getting a comment from you.

TheFoofinator (author)2015-06-25

This is a great implementation of the idea, I remember Dunkis talking about this waaayyyy back but no-one seemed to make it work. To decrease the fire rate, use a small tire on on the same shaft as the band cog to induce a bit of friction on it. Should slow things right down. Also make a brake shoe with an adjustable grip force to push against the tire, to vary the force rate as needed.

Thanks! I wish I would have thought of that tire idea when I still had this gun. I'm planning on rebuilding this again in the future and try and get this working a little better. Question, you still building with knex?

Unfortunately not, as I'm currently at university/college, about to go into a job at an Engineering company.

Overall a pretty decent design, not really full auto, but a decent gun all the same.

Lucas The Boss (author)2015-06-15

Ok, could you reply your
Phone number on G+ so I can add you as a contact

dr. richtofen (author)2015-06-15

You could maybe use whatsapp or facebook messenger, or something like that, as both should be free, when using wi-fi.

Lucas The Boss (author)2015-06-14

Oh crap, I don't have skype and my mom want let me get it. Can we just text pics of the gun?

Kona-chan (author)2015-06-09

it doesn't have a mag now does i

Lucas The Boss (author)Kona-chan2015-06-14

No :( I had to take it off since there was less room after I changed the mech and plus it fired to quickly for the mag to reset itself.

Kona-chan (author)Kona-chan2015-06-09

*it .

EpicMinecrafter870 (author)2015-06-13

Nice blocky style. If you were the guy who made the Call of Duty knex guns, then I have a suggestion. Do an SN6.

I might do it, I've got a lot on my plate right now but when I start getting through with request and collaborations I'll get right to it.

Lucas The Boss (author)2015-06-14

I sent it

Lucas The Boss (author)2015-06-14

FaceTime, do you need my phone number or email? I'll pm you it on G+

Doc Penguin (author)2015-06-14

not entirely full auto, just lets out all of the lastics at once, more like a shotgun.

Still, good job

Not all at once, I've slowed it down so there is a noticeable difference in each shot. I think I've slowed it down enough to possibly put a mag, but the problem Is where do I put a mag since I put the lever closer to the front of the gun. But thanks!

Lucas The Boss (author)2015-06-13

Schools out for me so I'm free whenever, I guess we are gonna do that war gun I told you about. Your gonna have to teach me about handle pumps though because I've never built one.

sandroknexmaster (author)2015-06-12

That's nice!

Lucas The Boss (author)2015-06-11

Agreed, like I told knex guy, I've slowed down the fire rate to a manageable level but is still much faster than I want it. Right now
It's like a Uzi that empties a 30 round mag 2 seconds, except mines only 6 shots now for the fire rate to have been slowed down. Hey man when are you wanting to start the collaboration?

knexguy237 (author)2015-06-10

Very nice gun! I don't want to sound like mine was better, (because I know it wasn't it could only hold two shots lol), but I feel like this gun could improve a little...I think if you make the thingy that is in the first picture able to move farther, the rate of fire could be slowed a little...right now, It looks like a regular burst, which I know you know that. I hope you didn't take this apart, because I know it's possible to make this gun possibly the first full-auto gun that actually works very well and is practical...but for now, I'd say that it isn't very practical, because of the reload time vs the firing time...also, with my gun, I could shoot one, then shoot the next, it didn't have to be all at once...I'd try and make your gun so the ROF is slower so you don't have to shoot all of your shots at one time and waste them...these are just some thoughts and some opinions on the gun, but overall, very nice job! (and that mech kinda looks like mine lol) I hope I can see this gun make it farther up the ladder of greatness.

Thanks! I have managed to slow down the fire rate to a controllable level but it's still not what I want. I had to move the thingy that the rubber band hits closer to the front of the gun. Then since it had already lost a lot of the tension it had at the back of the gun so it kept getting stuck on the lever. So then I had to make the gun longer so there would be more tension. Then my biggest problem, now that there's more tension on the cog, I can only put 5 on the cog or it will explode from all the pressure. I don't know what I'm going to do about that.

It's kinda funny that what you're experiencing is exactly why mine would explode...the tension is too much, yet the only way for it to work slowly is if the tension is that much. I think all the major K'nex inventors need to meet together and find a way to get this done haha

sonic broom (author)2015-06-09

Neat! it looks very interesting. A little two many cut parts for my tastes. But nevertheless it is pretty cool!

CorgiCritter (author)2015-06-08

That's pretty nice. You did a very good job with the looks, acyually.

Really, I thought it was a little boxy for my taste but hey to each is own. Glad you like it!

I like boxy guns. The last gun I attempted had the sole purpose of being one the sturdiest and most reliable mag fed gun. It was a fail, of course, since I ran out of parts for the stock. But it was nice and boxy and sturdy. Not to mention the sweet preloaded blue rod magazines with only on cut rod.

I think I need to work on more guns with preloaded mags.

myOmy (author)2015-06-08

Interesting. Might build. I like it.

Lucas The Boss (author)myOmy2015-06-09

Thanks! If you do build it can you try slowing down the fire rate. I'm going to try in a little while but I want to see what you come up with.

About This Instructable




Bio: Knex builder here at Instructables. I build Guns, and, Roller Coaster. I currently build about 2-3 guns a month. I strive to post quality as ... More »
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