Author Options:

The K-3, Shotgun Internals, and The Failed K-4 Answered

Well, I am pretty tight on time at the moment, but the video should explain things pretty well until I can do so here.  here will also be many more pictures of the K-3 and Kinetic Shotgun, but I just need some time for those too.

As for the K-4:
Everything worked the way it was designed to work, but certain mechanisms (the trigger and the BTS) required a lot of force to function, thus reducing the amount of tension that would be even remotely practical to use on the bow.  It was a good attempt and I have learned a lot from it; things that I will take with me as I move on to bigger and better guns.

Here's a video for now, and I will explain everything in depth as soon as I can.



amazing as usual. i really like what you did with that little thing you showed us all that time ago for the K3. nice! i'd like to see some more pictures though...

the K4 is still awesome... though i had a feeling you were gonna go for that trigger setup, and i just knew it wouldn't be able to handle the pressure. you should have anticipated that, dude... nvm... what i don't get though is how you attached that little thing pulling back the string to the pump... i know it's stupid, but i just don't see it lol. so if you can, show me that. no need for the pump itself btw, i figured that out a long time ago.

about the 3252, no, i'm not working on it anymore, but maybe obliv still is. at some point we had different ideas on how to make it 5 layers, and we split up to work on our individual ideas. i finished mine pretty quickly (2-4 days, i think), and it was 5 layers and it worked amazingly (about 25 feet). i took it apart later because i needed the parts, and i made a very long video about it that anyone could build it from that. back to oblivitus, i don't think he ever came up with anything better than mine, or at all 5 layers, but on second thought, i actually think he told me he was gonna try to make other guns using some of the mechanisms from the 3252. for example, his Z3 uses the alternating mech from the 3252. oh, and another note is that the 3252 is a semi auto concept, not a full auto concept.

about my concept, i'm deep into building it, and i'm pretty sure i can make it work in a moderate sized gun. first i just wanna make sure it works, then i'll perfect it. have you done any work on it? i actually think i might need your help with the trigger. i mean, i have something, but i get the feeling it'll be really sloppy and bad, and i just love your trigger designs, so... i'll let you know.

and last, how's your closed barreled sling going on?

Thank you. Yeah, it was a cool mechanism, but that is about it. I got rid of the hammer firing system so that it is just the lever and main cog. I am using that to pull back the string for your closed barrel sling, and so far it works, but I still have to mess around with it, and I have not had time lately, seeing that all my free time was going into that damn sling pistol so I could make the deadline.

Yeah, it was really a stupid mistake. I think I am going to try a v.2, with a different loading system and of course a different trigger system, but that will have to wait a while. If you look closely, you can see that the string simply runs through a hole in the "ram". The ram really isn't a ram, just something that pushes the bullet out and allows the pump a way of pulling back the string. Two blue rods stick out of it, and that is how the pump pulls it back.

That's great that you guys got it to work, although I don't think I ever saw this video. Where can I find it? And yeah, I know I said full auto in the video, it was just a mistake on my part.

And finally, I really have not had a chance yet, sorry. I have been contacted by a builder who wants to do something similar, but with rubber bands instead of preset firing pins. He is moving soon so I have to put that project as my priority. But I am very interested in both, since the overall purpose of the concepts are the same. And I would be happy to help you out with a trigger mech; I don't think it should be too hard, but it does depend on how you have things set up.

lol, true. good luck with that. i'd love to see a picture of that, if it's not trouble.

i forgot to answer the rest, stupid i know lol.

gl with that too. i realized there was something pulling the bands, i just didn't see how it is connected to the pump. i see it now though.

k mistakes happen. i posted the video unlisted in youtube on our 3252 work space page. and btw, that is my version... he was working on something else.

is this builder on 'ibles or just in your neighborhood? anyway, good luck to you two with that. i don't see how you would do it with rubber bands though. it is very hard. take these two thing in mind:
1. the gun is completely open in the middle. there is a very big gap where the pin carrier goes, to allow it and the pins themselves to go through the gun. for that reason, the trigger has to go a long distance around, and block in a very direct place in a very strong way without going too much in any direction (other than up) when you pull it to not interfere with the other mechanisms very close to it (everything works on a small space, since the pin carrier itself (not including the pins) needs to be small, for the obvious reasons).
2. you need to have two horizontally aligned triggers that work in an opposite direction when you pull the trigger. one should go up and one should go down. that is to maintain a semi automatic action and not a fully automatic action. a full auto with this concept is easier to make, but it would take a long time to load and a very short time to shoot. plus, i don't think knex full autos are practical. back to the trigger, it's hard to make this because it's aligned horizontally (on different layers on the gun) and therefor can't be like the one i had on my RBG semi auto TD asked me to make, if you ever saw it. you need to make two separately acting, opposite mechanisms that are activated by only one trigger, and need to overcome the trouble of distance (everything gets weaker if the crane arm is longer, because knex bends when it is pressured).

i would still appreciate help though.

I saw the video of the 3252...and it was very impressive. You could even just incorporate a ratchet in the trigger to give it the same alternating effect, just without ever having to take your finger off the trigger.

But anyways...

The builder is Innovana, a relatively new builder who I discovered on Youtube. He has some great ideas, but is having a little difficulty in the design process. He has already had some success in this gun, but it still needs work I think.

As for the trigger...

So you are using the "up, down" mech to allow the mag to feed in a little ways until it is stopped? If that's right then I see exactly what you mean. But there are other ways too. What I was thinking was actually a gear or wheel feeding mechanism. What does that mean? Well you slide the mag in, and it is in direct contact with a rubbered wheel, and thus will not move much due to the friction of the rubber. Now, that the trigger will do is, either by using a ratchet or using a trigger like in the 3252, turn this wheel (via crossing gear sections), and turning the wheel or gear that will be in contact with the magazine. This slides it through (we might be able to get 2-3 shots per trigger pull if we set up ratios correctly), thus setting off the pins and firing the bullets. Does that sound any better? Idk I just thought it would take some of the "plastic" factor out of the equation. And of course I would be happy to help you whenever I can. Do you have skype or anything?

yeah i know. i only talked with obliv about it like 5 times and had like 7 other people telling me that. i know what to do and how to do it, just that back then i was too lazy to do it, and now i'm not working on it anymore.

i can't find him on youtube or on 'ibles (though i didn't expect to find him on 'ibles).

yes, i see what you mean, though i think a cog pulled by a band to move the mag would be better, since it would move it better and more reliably, and i think my sort of trigger can be done, just it's difficult. i don't know, i might try your idea, but i don't see it being better. btw, one of the reasons is because with crossed gears, since knex is, after all, a plastic kid's toy that bends and is far from perfect, it is less reliable, since they have a small surface to catch onto each other and they can get separated pretty easily.

yeah, sure. skype. search me on skype, or i'll search you whatever. my name is Daniel Sharir. although, i think a text communication is better for this situation because you're in the usa and i'm in israel. the smallest time difference (from the east coast) is 7 hours (israel is 7 hours forward. i.e. if the time here is 7:00PM, there it's 12:00PM). where exactly do you live, btw?

on another note, i made your sling pistol, and although i'm pretty sure i didn't perfectly copy it, it didn't work very well for me. every time i cocked it, a second bullet would be released just behind the first, and i would have to insert it back in to the magazine. also, the slide didn't slide too well, even when i loosened it a bit (though it did help a bit). except for the cocking which was kinda bad for me, i really liked the trigger mechanism, and it did shoot pretty strong and pretty accurate.

are you building any of the challenges now? i have a pretty good folding gun, and i think i know how to make the revolver thing.

No, he's on here, I might have just spelled his name wrong.

Ok, so I'll send you a friend request or whatever it is on skype. If we can catch each other I think it would be effective. I live in Rhode Island, USA, so yeah, we will have a seven hour difference. I actually have a friend who was born in Israel and is now part of your airforce, btw.

And yeah, there are some hidden things, especially in the magazine and the slide, that would effect reliability if done improperly. And because of the unpredictability of rubberbands being used to push back the mag block, the gun jams because the band starts to push the bullet forward before the block can actually keep the next bullet from entering. It is a pain in the ass, but I would just say to try messing around with different blocks, with the intent of reducing friction between it and the rest of the gun.

And, no, unfortunately. I have a pretty cool design for a folding gun, but I am going to take this challenge off and work on some other things. I don't think the revolver should be too complex though.

Make sure to post the shotgun and the K-4. I love the K-4's mech.

Sorry man, but the K-4 is long gone. I have full designs of the mechanism though If you want me to post those, in case you could try to make it differently.

Man I was looking forward to a gun firing a nearly indestructible round like the K-4 did. And having a mag was just icing. Oh well. I see potential in the shot gun. But not the full auto. Sure it will perform great for a hammer gun but it's still a hammer gun. 1-10 is the range a fully auto is used at so I guess power isn't as important

Don't worry man, I am definitely going to revisit the project, but I currently have three guns on my hands, and am a bit overwhelmed. One of those projects is a new gun utilizing part of the K-3 mechanism to pull back a rubber band, in order to create a closed barrel sling (Sharir's idea). It fires pretty well at the moment, but I still have some things to work on. But at the moment, the sling pistol has taken priority because it is due on friday for the contest. But again, I will have something that shoots the K-4's ammo by the end of the summer, so don't you worry.

Thats good. I'm tired of breaking my rounds when they miss and hit the wall. Keep up the good work and post everything you can.

Managed to make it from the pictures. Only problem i had is the "pump" bit broke when i first used it - dunno if you've re-inforced the bits that pull the "mag" part back tho as i can't see them properly


Are you talking about the yellow connectors that stick out to pull back the box? They are connected to the rest of the pump by a white rod and a green rod. I can get a couple more detailed pics of the pump up later today if you want.

On the pump you have the blue part of a hinge connected to a grey spacer - from the pictures these seems to be what pulls the "box" back. Going by your comment tho, it seems that these may actually be what the pump runs on. If you could post up some pictures of the pump as i can't see what else could pull it back. As for posting an instructable, i don't think i could as i've basically used up all my yellow connectors and green rods making it. I could try and take some different photo's of it if that would be alright?

Hang on, i've just had another look at the pictures and seen where i went wrong. I must have over looked it .. when i make a gun i photograph all the pictures/instructions with my phone and then make it off that, rather then sitting at the computer.

Yeah, the joints are meant solely to guide the pump. The first two available spaces are for these guides, and the one closest to the box is occupied by a yellow (grey for me) connector that comes into contact with the red connectors on the box.

And do you think that you could post an instructable for it by any chance? That would be a huge help.

BTW, I really like the lever action-auto concept, the mechanism looks like it could have quite a bit of potential use in future guns. Also, be on the look out for my Bolt-Action bull pup assault pistol (I'll come up with a better name.) I finally got my mechanism working for the gun, I'm probably going to create a folding stock of some kind if I can before I post a slide. The slide should be should be up by tomorrow. It doesn't sound interesting at the moment, but once you see it you'll think otherwise hopefully. I tried to make the gun pretty compact.

Yeah man, I just saw the bolt action and it looks great. Amazing job man.

I am current using the lever system in Sharir's "closed barrel sling". It works, but I think it has a long way to go before it serves the purpose of the concept: to greatly increase the tension capacity of sling rifles.

All those guns look pretty damn kool. I'm still dying to make the shotgun :)