Introduction: Z3 Knex Gun

Picture of Z3 Knex Gun

So here's my big post of the year.

I've been working on this for the past 4 months. Pump once, fire 3 times semi-automatically. Gets 50 feet of range. The gun weighs about 9 pounds. I still have some work I'd like to do on it before I post instructions. One of the things I'd like to do to it is double the capacity by adding another revolver wheel and draping a longer ammo chain (about 36 rounds) over the two wheels. The second wheel would go directly under the current one.

The section that sticks out in front of the pump is to rest it on things. The white connectors on the butt prevent it from sliding up when cocking and down from the weight. It uses an alternating trigger system and three barrels. It also uses a new system for spinning a TR-18 turret.

Hope you like it. It takes a butt load of parts though.

Check out a video of it here.

I am also an artist! Like me on Facebook!


Oblivitus (author)2011-12-10

Make sure you all check out the video!

TheKnexChicken (author)2016-03-21

this is one heck of a gun! amazing! that must have been time-consuming to make

hawk45 (author)2013-03-31

will you post?!

Oblivitus (author)hawk452013-04-01

I already did.

Sharir1701 (author)2012-08-23

are you still working on the model for this? man it would take 20 hours tops (not straight, obviously) to make a normal instructable from scratch (take it apart, take pics, rebuild, upload, add notes and stuff etc.) for this... it's been over 8 months and you still haven't posted it !!! i mean, i could build it easily from the pics and the trigger mech you showed me, so i'm not saying that because i want it posted that badly, i just came across it and thought you were either really stubborn to insist on making an mlcad model for it, or you just lost interest in it, so i had to post this comment... also, i posted my S3, finally... you said you were going to work on it to get a turret on there... do you stand by that statement?

Oblivitus (author)Sharir17012012-08-24

I stopped working on it a few weeks ago because I got stuck. I'm going to finish it eventually...'s annoying me. I have a majority of the instructable done. Yeah, I want to build your S3 after I finish the instructable and free up some parts and do some kind of improving to it. I haven't been doing anything with knex for weeks though, been writing music everyday recently. I'll get back to the knex sometime though.

Sharir1701 (author)Oblivitus2012-08-24

ok sounds good. hope you finish up with it soon so you can focus on the 3252. i wanna see what you come up with. also, i remember you saying you think paper is too big a manipulation for you, so i was wondering if you're gonna be stubborn again and try to find another solution, or make the gun thicker, or just use paper.

Sharir1701 (author)Sharir17012012-08-23

also, you know, i just figured that means you also haven't posted anything new in over 8 months... have you even been working on something since then (of course, other than the 3252)?

Oblivitus (author)Sharir17012012-08-24

Nope. Nothing new this year besides the 3252 stuff. Did about 100 hours of painting this summer and probably 200+ hours of writing and practicing music so not as much knex.

~KnexBuild~ (author)2012-01-11

Does the pump cock all three pins, then does an alternating trigger
mech allow the three pins to fire in succesion, allowing for three shots of semi auto?

totoandamigo (author)~KnexBuild~2012-04-05

it works like a revolver you pump once and it cocks all the pins then when you pull the trigger it spins the cylider and fires

Sharir1701 (author)totoandamigo2012-08-23

in what universe does a revolver work like that?!

~KnexBuild~ (author)totoandamigo2012-04-05

Actually, it uses a K'nex wind up motor to spin the turret, and it doesn't fire all of the pins at once.

PotatoCoffee (author)2011-12-27

Wow! You're going to post instructions? That'll be Awsome!

Oblivitus (author)PotatoCoffee2011-12-27

Haha, thanks. Yeah, who spends 4 months on something and doesn't post it?

PotatoCoffee (author)Oblivitus2011-12-28


Oblivitus (author)PotatoCoffee2011-12-28

Really? But those are the best posts.

PotatoCoffee (author)Oblivitus2011-12-28

Not always.

Oblivitus (author)PotatoCoffee2011-12-28

But this is. I'm not sure why you'd think I wouldn't post it. If someone works hard on something and it turns out well then they should post it for the benefit of others. That would be like a scientist who doesn't share their findings or the artist who doesn't share their work.

PotatoCoffee (author)Oblivitus2011-12-28

It's just 9 pounds of awsomeness is going to take a long time.

Oblivitus (author)PotatoCoffee2011-12-28

Yeah, it'll be worth it though. Thanks.

PotatoCoffee (author)Oblivitus2012-08-19

You posted!

Oblivitus (author)PotatoCoffee2012-08-19

No... What made you think that?

PotatoCoffee (author)Oblivitus2012-08-20

Umm... Mistake! BTW you're my 900th commenter!

Oblivitus (author)PotatoCoffee2012-08-20

My favorite chase scene ever.

PotatoCoffee (author)Oblivitus2012-08-23

I think it's everyone's favourite..

Knex.X (author)2012-05-25

Damn, how did you ever figured that out?

Oblivitus (author)Knex.X2012-05-25

Ha, thanks.

the_sheep_cheese_man (author)2012-01-22


That;s what she said.
Sorry, I had to.


DrWeird117 (author)2012-01-01

Oh my. Despite the bright colors, I'd be lying if I said I wasn't intimidated, haha. I'm not even going to attempt building this beast. Looks incredible.

Lowney (author)2011-12-29

This is good and all but it's a bit small isn't it? :P

Oblivitus (author)Lowney2011-12-29

Yes, I tried to make it bigger but it kept bending the floor and every time I took it outside a bird would fly into it.

prodo123 (author)2011-12-29

Your guns are as monstrous as usual, Oblivitus.
It's a shame I don't have enough parts though, I'd love to build this!

Football viking boy (author)2011-12-10


Thanks! I'm not sure how many parts it takes though, my guess is that you'll need at least a couple thousand.

Sharir1701 (author)Oblivitus2011-12-11

probably more like couple dozen thousand lol. but seriously, i don't think it takes less than 5,000 parts...

Oblivitus (author)Sharir17012011-12-11

Oh I don't think it takes that many, but yes, it's in the thousands.

i have enough to make it, can't wait for posting!!!

Sharir1701 (author)Oblivitus2011-12-11

i think you're underestimating the amount of parts in your gun. it happens often.

Sharir1701 (author)2011-12-15

by the way, i have another question. if you pumped, fired, say, one or two shots, but NOT all three of them, can you pump again, just so that you would have 3 shots again?

and once again, great job. i especially want to see the trigger system, and the way the pump is held in place (i just want to compare it to my system of holding the pump in place). i hope you can get the 'ible out as soon as possible. even if you could just take out the outter layer of the pump area to take a few pics and post them in our SA v9 working area, i'd be happy.

Oblivitus (author)Sharir17012011-12-15

You could pump it when one or two of the pins are forward and it would cock them but the turret doesn't rotate until you fire the round on the right. To give an example, this means that you could fire the left barrel, cock it, fire the other two barrels, it spins, fire the left barrel, cock all 3 barrels, fire 2 barrels, cock them, fire the right barrel, it spins, fire the other two barrels. So uhh, now that I think about it, yes, you can pump it when only one or two have been fired. In fact, I think that will always work because the one you're cocking is always at least one trigger mech rotation behind the one you're firing. And the turret will always spin before you hit an empty slot.

Therefore, you can cock one or two barrels and continue firing as normal without the gun malfunctioning. This would allow you to go from having 1 or 2 shots ready after firing to having 3 shots ready at all times.

Or in short, the answer to your question is yes.

Yeah, I can do that , when I start the mlcad model I can get you some images of the pump at the least. The trigger system will take some time to accurately show however. You might have to wait for the instructable for that part.

Sharir1701 (author)Oblivitus2011-12-21

You know, I think I know how we can get out of our stuck position on the SA 3252. If you're available right now to do some work on it with me, actively, and pause for a week or so on the mlcad model of the Z3, i'll talk with you about it on the unpublished 'ible. My idea isn't new or anything, but it'll get us out of the stuck position we're in now for sure. So I hope you're available for it.

In the meantime, can you maybe make a sketch of the trigger mech so I will be able to understand how it works and perhaps try to utilize it on the SA 3252?

By the way, remember I promised you I'd have a lot of time in mid December because of a holiday? Well it's here ! I have a ton of free time this week. I think we should try to use as much time as we can this week to take a step forward with the project. My holiday will be over by next Thursday.

Oblivitus (author)Sharir17012011-12-21

Yeah, if you want to post photos/videos and explanations of what you're doing I'd be glad to help however I can.

Yes, I'll do a sketch of the Z3 mech for you. It's basically a stronger version of the alternating mech.

Sharir1701 (author)Oblivitus2011-12-21


Seleziona (author)2011-12-10

So what you're trying to say is that it needs to be this big? Magnificent gun, by the way

Oblivitus (author)Seleziona2011-12-10

Thank you very much. Yes, this is the absolute smallest and lightest that I could figure out how to make it while still functioning properly. Once I post it and you see the gigantic trigger mechanism in there it'll make a lot more sense.

Seleziona (author)Oblivitus2011-12-11

Well, I can't wait to see it then. You've always got the best stuff, and you never fail to please anyone with all of the marvellous creations you make. Good stuff!

Oblivitus (author)Seleziona2011-12-12

Once again, thank you. I actually did one thing in particular with the trigger mech that once I made it I just sat there spinning it out of wonder and amusement for at least half an hour. The clever simplicity of it is mesmerizing. You know what I mean? And it has nothing to do with the fact that I invented it. I could do the same thing with one of those wooden criss-cross do-nothing machines. It's just something about the design that's mesmerizing like a lava lamp.

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 GunZ3 Knex Gun Firing Demonstration
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