Picture of Knetix semi auto knex gun
This knex gun is different from other semi auto guns because instead of using manual power to pull back the pin, the tension of wound rubber bands is used, making the trigger easier to pull and very unlikely to break when you pull it.

I give credit to extreme builder for the pullback mechanism (the black wheel)

I also give credit to revtiedye for the trigger and placement of the band wheel

Semi automatic
Very sturdy
Shoots farther than most semi auto guns (about 15 feet)

Needs to be wound every few shots
Does not shoot as far as a pull-back gun would


Step 1: Frames and main supports

The body frames and mandatory supports of the gun. This step also includes the safety lock
LvNo10002 years ago
Why isn't "requires a bunch of broken pieces" in the cons list? It would have been nice to know that before I got nearly half-way through making it and realized I wasn't willing to break that many pieces to make this.
TheRacker4 years ago
Kind of obsolete now, isnt it?
only shoots 15 feet????? there are a lot better semi auto guns
Kinetic (author)  Football viking boy4 years ago
Hmmm...this gun is three years old maybe? And yeah there are but they're pseudos. If you want to see an amazing semi auto check out my forum semi auto. Not sure when it will get posted though because it still needs work.
Crumble4 years ago
is there an easy way to break the grey connector in step 1 pic 9?
slippdiddy4 years ago
AMAZING!!! i love it..... im building one but it has a second ram rod (or fireing pin) that smashes in to the firing pin to pull it back after you shoot, then on your second shot you pull the same trigger but it uses a different mech.... and there you have a semi auto..... but it only shoots two times then you have to cock it (so its not true) :( but i still like it and im getting close (im just on the concept) ....... awesome gun
here it is --->> http://www.instructables.com/id/Semi-auto-knex-assault-rifle-SAKAR/ still not realy working :(
glugnar5 years ago
looks awesome
Is there a video of the gun shooting?
An Villain5 years ago
my rating boosted it over 4*
Madrias3575 years ago
I have a method to rid yourself of the chain.  Use the little sized k'nex wheels, and a rubber band.
Kinetic (author)  Madrias3575 years ago
 Maybe-it might not grip well enough though. Good idea however.
you seem to use the same stock and handle in ur guns
KnexFreek5 years ago

it looks really cool :) !!!

Kinetic (author)  KnexFreek5 years ago
devon345 years ago
its good but your handle is a bit rubish
Kinetic (author)  devon345 years ago
What makes you say that?  Works perfectly for me.  And if you have a problem with it you can easily mod it to fit your wants. 
devon34 Kinetic5 years ago

i havent made it but it looks a little bit fimsy

Kinetic (author)  devon345 years ago
It actually works fine, since it is 5 layers thick. 
devon34 Kinetic5 years ago
is it powerfull and what does the chain do
Kinetic (author)  devon345 years ago
The chain connects the band wheel (where the energy is) to the firing pin.  It gets about 10-15 feet.   
GeekBeam5 years ago
how many and what pieces do you need
Kinetic (author)  GeekBeam5 years ago
Sorry man this gun was taken apart a long time ago.  I have no idea.   
Knetix6 years ago
hey ppl sry i havent been answerin any questions-i lost my old account (kinetic) so i see that there is a lot of controversy about this gun. Yerjoking-i lookd @ ur profile and i dont c any semi autos at all so dont be trying to compare us-and also-oodas semi auto inst really a gun-more like a handheld cannon-guns use triggers, not levers-of course u can get more power uf ur usin ur whole arm instead of just ur fingr-no offense 2 ooda- its still a great design
GeekBeam Knetix5 years ago
oh no need to worry it happens from time to time, sucks when you have a good account going ,and *poof* it's gone
Kinetic (author)  GeekBeam5 years ago
Actually I just couldn't remember the password but I figured it out afte a while thank god lol 
DrWeird1176 years ago
Damn it! This is cool, and new. Why so many complaints?
because ppl think its not TSA
They should actually build it.
duh they need to build it before they critique it im going to do so later on
my revolver is probably one of the closest guns to semi auto it uses a sharpened ball connecter to hit the white rod in the bullet holder of a rotary drum, it uses a hammer to help this and all 8 shots can be pulled in under 5 seconds heres pic:
ooh aah cool looking gun man
u should post it--i would build it
GeekBeam Knetix5 years ago
me too
It's not the closest to a semi auto, we have semi auto's already, lol. Never seen a fully working semi auto revolver yet, only seen certain parts.
Combine BRv1 turret with Ednator 55's semi auto mech.
Kinetic (author)  DJ Radio5 years ago
 Thats actually a really good I'm going to try that some time.
Then you have a gun which will shoot even worse than the original gun.
Yeah, but semi autos are not power guns, but concept guns.
But you want a gun that can shoot atleast 10 feet with semi auto.
OH COME ON! I built the entire gun, up to adding the gears, only to find I CANT FINISH IT BECAUSE I ONLY HAVE ONE GOLD GEAR! Epic failed.
hey dont you have a grey gear that doesnt attach with tan locks like the other gears(its one of the earliest gear types knex made)
Kinetic (author)  agent harmsy6 years ago
thats horrible-it might work with just one but if might break
agriff6 years ago
what is the chain made of?
chazman2 agriff5 years ago
der its knex
Plastic K'nex chain pieces
squarepants6 years ago
the handle looks kinda unfinished with the white rods stickin out
Kinetic (author)  squarepants6 years ago
na i do that on purpose-i just like it that way you can build it however you want though
thats a nice idea-built it to suit you.
beameron6 years ago
Heres an idea Iff u connect 2 of those pull back things for the trigger. U can make it pull back further xD
yerjoking6 years ago
Still not true true semi auto, it needs elastic bands to fire bullets.. STILL, good gun, 3 stars 'cause I thought it was true semi auto.
Kinetic (author)  yerjoking6 years ago
what do you mean 'it needs elastic bands to fire bullets" ?
The elastic bands hit the ram and the ram makes contact with the bullet, and then you need to "Re-wind" the gun, unlike a true semi aut where you only have to put the mag in then pull the trigger.
Extreme builder made a true semi auto exept it has a built-in magazine
I made one with a removeable bottom loading mag, lol.
cool i wish i could see it
It wan't that good, shot 15 feet max, and prone to jams, due to the mech. I do plan to make a v3 that shoots discs though.
Was still tru semi.
Kinetic (author)  yerjoking6 years ago
ya-but unlike a regular gun, u can wind it multiple times, giving you multiple shots before rewinding
So? My semi auto, and Ooda's Semi auto's don't need winding, BUT, I like your gun, and you did a fine job with the new mech, maybe someone could make it fully auto...
it is too true semi auto! is shoots every time you pull the trigger! T-R-U-E S-E-M-I-A-U-T-O!! 5*
No, it really doesn't, if it needs "winding" then it ISN'T SEMI AUTO. Don't tell me it is, and I changed it, I rated it a 4 'cause of the design. Not true semi auto, but a good idea.
I thought it fired rods!
it does-u need help?
the instructale is nice, but this is still not a semi auto. maybe with some more knex you can make the look of it better. its just an idea. well done 4*s
lilrou156 years ago
cant you just use a gear to turn the chain not a snowflake?
Kinetic (author) 6 years ago
does anyone know if its possible to upload videos without using a link to another site?
DJ Radio6 years ago
may build sometime. 5*, and faved
Kinetic (author)  DJ Radio6 years ago
sweet thanks-if u build it tell me n e mods that u made-especially ones having to do with the way that the rubber bands wrap around the band wheel-the most ive been able to wind it is 2 times so far
what is the wheel with the chain for?
Kinetic (author)  ILIKEPIE3336 years ago
it connects the pullback wheel to the band wheel. I couldnt use gears to connect the pullback wheel and the band whheel because they would get in the way with the inner parts of the gun
ok, thanx
DJ..... why do you give him false hope.... we all know you dont have enough peices to build
ill get enough parts sooner or later....
banned? Huh?
Knexwizard6 years ago
I was thinking of making it but I want to see it in action.
wow! I like it cos it lookes so... eccentric, but a video of how it works would be reeeealy nice. I dunno if I wanna commit the pieces until i see it in action. I'll give it 4*, with a 5* rating if you upload a video.
Kinetic (author)  agent harmsy6 years ago
k-it does use a lot of pieces and it was mostly made just for the purpose of being semi-auto, so it doesnt shoot as far as a regular gun does, but ill try 2 post a video 2 persuade all u ppl
hmm, I won't make it yet... too many broken + modified pieces! but if you get that video up, I could well change my mind...
can you explain the gear system more. With all the gears and chain i dont see how it works?
Kinetic (author)  codemaster25906 years ago
sure-when you pull the trigger, you allow the band wheel to rotate once. when it spins, it turns the other gears that connect to the chain. since it is connected to the pullback wheel, when the chain spins it causes the pullback wheel to spin. the teeth on the pullback wheel use the spaces in the firing pin to pull it back as it spins, and then it fires. it happens really fast when you are actually shooting the gun but thats how it works.
5 stars and favorite
Kinetic (author) 6 years ago
pls6 years ago
Looks interesting, 15 ft for a semi auto i think is great! Video would be awesome aswell!
Kinetic (author)  pls6 years ago
ya-ive gotten that a lot about the video-ill post one soon
pls Kinetic6 years ago
Oblivitus6 years ago
Looks interesting, I see that you have a semi-auto cog mech and I think that is a reseting firing pin, but I still don't understand how it works so please post a video!
Kinetic (author)  Oblivitus6 years ago
Ya that would help-u just dont hav n e gears left so i wont b able to work on that now-ill post as soon as i figure it out
Kinetic (author)  Oblivitus6 years ago
k ill try 2 get one up-it works cause wen the trigger is pulled, it allows the band wheel to be turned by the bands and that in turn spins the pullback wheel, pulling back the pin and releasing it
Ahhh, okay, I have an idea to improve in that case, if you put a wheel on there, you can wrap elastics around it, allowing you to get many more rotations per elastic that you use.
very cool and thanks for some credit but we need a video like i did
Knexwizard6 years ago
do you have to breack this piece
Kinetic (author)  Knexwizard6 years ago
o that one-i guess you dont really have to, but breaking it allows it to move up more, allowing it to have a better hold of the pin while you r winding
Kinetic (author)  Knexwizard6 years ago
which one?
Kinetic (author) 6 years ago
ok ill c if i can get one up
We need a videa!
MI66 years ago
V. complex but i still like it a lot
Vynash6 years ago
This is very cool! But I wont be building it. 41/2*s!