I'm still working on this, but here's the latest.

How this version will work;

This gun is powered by a large elastic that is hand cranked around a spool. The different mechanisms are linked to each other by gears. The blocking mech section of the trigger mech moves at half the rate of speed that the spool and firing mech move. This is because the blocking mech blocks every 180 degree rotation, while the firing mech needs to operate on 360 degree rotations. The gun uses an "alternating" semi-automatic trigger mechanism that unblocks one block mech, while the other remains in a blocked position. This ensures that no matter how slowly you pull the trigger and no matter how fast the firing elastic rotates the mechanism, the trigger will not fail to block the mechanism in exactly one rotation.

I'm still working on this version, but I got good results in previous versions. Upon completion, this will likely fire 6 rounds from a magazine 30 feet semi-automatically before re-cocking. I intend to take this design to the end, not stopping my work on it until it can function no better.

UPDATE: I've begun working on version 8. Turns out 7 had some problems. 8 will still include gears, an alternating trigger mech, and the same firing mech, but I'm totally redesigning the rest of it.
I smell it....a new era of K'nex mechs....and we're peeking around the corner of it..
That was epic.
Great, if this takes off I can see a step forward in the K'nex community.
Yes, thank you, that's exactly the purpose of this gun. It's about the potential of the design. There are so many applications of this and ways to improve it.
"re-cocking" Not a semi auto.
I think he means you just cock it once after loading, then pull the trigger and it shoots like a semi auto. No cocking needed after the first one.
Right, you wind it up six rotations, then it shoots 6 rounds without rewinding. The process is repeated after every six shots.
That's not semi-auto then. That's like pumping a shotgun 6 times then firing off 6 shots. You still had to pump once for each shot fired, but just not right after firing.
D: there's always so much contravercy on semi-autos that I wouldn't be surprised if someone set a whole site up for discussion about it.
There has.
It fires 6 rounds in a row, one with each trigger pull. That is semi-automatic fire. Do not insult me.
Well if you don't want to be "insulted" make a true semi auto. A true semi auto requires no prep for firing the gun aside from loading ammo. This gun requires winding.
How about you make one?<br><br>No one has ever invented a true semi automatic, at least not one that fires k'nex pieces or rods.<br> Like a real semi-automatic rifle works with electricity or is gas operated.<br>How do you expect that someone wil make that out of k'nex.<br>at least Oblivitus is trying.<br>
Oodalumps made the wasp a true semi auto
I tried, i used a hammer method and each trigger pull brings back the hammer to fire knew peice out of a turret. its on my page.
You're alive!!!!
Actually, (not directed at oblivitus) there are many semi autos out there. Louis XIV was one.
http://knexinnovation.net/showthread.php?1108-WASP-War-Assault-Semi-automatic-Pistol Relax.
I consider that as less of a semi auto, at least in the respect that it doesn't have a power supply. Although it's more of one in the sense that it doesn't require cocking.
Actually, all semi auto guns need cocking for the first shot, after that the gasses released from the bullets detonation reloads it.
You sir might have have the IQ of a shovel. This is a true semi auto.
Good joke, Kevin.
Haha sorry bout that. Also i realized you are right, a true semi auto requires no prep other than ammo. I just try to keep ppl from saying things about oblivitus and/or his guns abd designs. He is very innovative
Not true. Guns would require one initial charge of the bolt before firing any rounds otherwise how would the hammer work? The exception being a gun such as a revolver.
Not talking about real guns.
But we take terms and ideas so we must respect the rules of the real gun world. That may not mean using gunpowder and lead bullets but we must remember that almost all trigger fired guns except guns like mini-guns and Gatling guns (which are externally powered) must be cocked and THEN fired.
theres the knex war assault semi automatic pistol that is truly semi automatic
I'm not going to argue with you about definitions. Who are you to come onto my instructable page and tell me that my gun doesn't fire the way that you want it to?
A person who isn't afraid to do so. I'm not sure why you are getting so offended. I like the gun. It's new, unique and has a lot of potential. I don't like how it is falsely named. :)
Thank you. All right, sorry, I misunderstood you. And I think I over reacted. I can't hear the tone of your voice in writing. I took your comment as meaning that you didn't think the gun was worth much. In the future, if you write criticism, make sure that the other person is able to see that it's constructive criticism. I would have immediately understood you if you had said, &quot;in my opinion&quot;, or talked about what you liked about it in the same comment. Sorry about that. I'm glad we could work this out. :)
Totally understandable don't worry about it. :)
If you're impressed by this, than check out the latest version by Sharir: https://www.instructables.com/id/the-S3-semi-automatic-gun/
I've seen it, this just looks very comlicated.
Hehe, yes, the catch is that it's not as complicated as the newer one though, the mechanisms are just bigger here. The current version is actually -get this- MORE complex in a THIRD the space.
I know, but this is squished into a smaller space, thus making it look more complex. Understand? Jeez... You just don't get mechanisms! :P
Wait, what?
*Sigh* If you put a collosal mechanism into a fairly small gun then it makes the mechanism look bigger! Wanneer zul je leren!
This is small?
Oh yeah, thats what she said...
*Compared to some.*
Any vids of your recent progress?<br>
I am going to work on a semi-automatic gun as well, similar but much, MUCH thinner, I'll see how it turns out.....
I like this.
here is a new best truly semi auto gun
UPDATE: I've begun working on version 8. Turns out 7 had some problems. 8 will still include gears, an alternating trigger mech, and the same firing mech, but I'm totally redesigning the rest of it.
<br>Are you going to add a stock? Because you should.
Could use a foregrip... 5*.
Yeah, I designed one on the computer, but I won't be adding it until this design is finished.

About This Instructable




Bio: I paint, write music, and used to build knex guns. I have a Bachelor's Degree in Studio Art. - updated 5/7/2014
More by Oblivitus:Z3 Knex Gun (3-Barreled Semi-Auto Pump Action Revolver) Z3 Knex Gun Z3 Knex Gun Firing Demonstration 
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