Author Options:

How Do YOU Design K'NEX Guns? Answered

K'NEX Gun Builders of Instructables,

The reason that I am posting this Forum Topic is that I would like to hear how YOU design YOUR K'NEX guns. What are your secret techniques and tricks of the trade? Please post your comments and answers below. Thanks!,

-The Knex Inventor


Just my two cents, I must pretty much echo what JBG, Kinetic, and TD have said they do, but if anything to an even more insane level (probably to my detriment.) I will consistently imagine a mechanism, and start by building the core of those internals. If you haven't already noticed, most all of my guns are concept guns, and it definitely shows. In starting with the core mechanism, that usually means that the trigger, magazine well, and even propulsion mech plus other moving elements end up being glorified bodges added nearly as an afterthought. Take, for example, my Jolt. The mechanism that I found so cool in that was the feeding mechanism for retrieving the rounds from the magazine. Unfortunately, that meant that attached to it was a half-assed slingshot that barely rivaled the average pin gun, and was significantly slower to use. Come to think of it, most of my guns are needlessly inefficient to operate, and aside from maybe my Zipdart and the forward assist rifle, really don't compensate when it comes to performance.

When I hit a home run, it can feel amazing to use as was the case with the Zipdart (principal reason I'm making a v.2 --end shameless plug--.) The mechanism in that case was indeed the propulsion mech, and despite its quirks it did accomplish what I set out to do. Unfortunately, I don't hit many of those home runs. Some of my guns can be a balancing act between a bunch of rubber bands, a few pieces cantilevered far further than Knex are meant to be capable of, and a gajillion other things that are far too complicated to be war worthy or even flat out reliable.

I design compact rube goldberg machines that may or may not serve their intended purpose. If that is what you want to do, here is more or less my process:

1. Have some idea for some part of the gun--literally any part (one concept of mine revolved around how a mag release could work)

2. Create an "in a vacuum, this could work" type of dismembered inner mechanism

3. Try seeing if that mechanism is even feasible with the limitations of Knex (size, shape, strength)

4. Begin the exercise in futility of trying to cram that mechanism into a body that isn't 20 layers thick and looks vaguely like a gun

5. ???????

6. Profit

Thanks for the advice, Dreamwave! BTW, are you still making K'NEX guns? If so, could you please consider entering one in my 2017 K'NEX Gun Contest? The contest rules and prize info are posted on the contest page.

I think I should have my ZipDart v.2 ready in a week or so, so I can probably make that work. Thanks for the heads up!

I'll warn you now, though, it uses a ton of cut pieces with most required for it to function. Most "white rod" length ones are not under too much tension though, so a long flexi rod cut into pieces will work fine

Okay. I have a couple broken white rods, but I may not have enough. I might have to sacrifice some of my flexirods.

Hopefully it'll make up for it in performance. 1ft rail, 50 ft+ in initial tests before any optimization or anything, and a fairly robust bolt in contrast to the v.1.

Well it depends on your vision. As more of a concept builder my builds are focused around a mechanical function as opposed to appearance. I usually start with a "Back panel" and try to fit the mechanism in it. I usually consider the normal standard of 5 layers max when I'm building as well, so the mechanism must fit in 3 layer. After I have a the mechanism finished, I clean up the edges and make it look more professional. Then its simply making into an interesting shape....

Pretty loose description but that's how I did things.

In terms of the concept itself, nearly all of my guns are the result of my attempt to either isolate the bullet, make a repeating sling, or make a semi-automatic mechanism. In many cases, the initial concepts fail due to k'nex uncooperative geometry, however while pursuing them I have come up with mechanisms that work great in other concepts. So dream big, build big, and at least you'll land among the stars...or something like that.

When it comes to building, my advice is similar to TD's. Build the gun around the concept, and never the other way around. Get it to work, then try to slim it down, make it pretty, ect.

I typically want to either accomplish something new or at the least try to improve on an old concept. I first start a very rough proof of concept. In the case of the Barackuda, it was my magazine. My current project is an automatic chambering repeater that uses an elevating platform, so for example all I have built for it is a rough idea of how I'd like the platform to work. I use a long panel of yellow connectors like above as a breadboard to see where I can fit in my concept and then what kind of barrel I'd like to use. Once I'm settled on a design for the concept, I build it near fully just to make sure it should actually work. Then I start building the internals and body around it. I typically use the same handle these days so I figure out where that best fits. Then I try to work in a firing mechanism depending on the kind of barrel I'm using. All the while I'm trying to keep my gun as clean and compact as possible. I usually put off the stock until I'm sure I like the gun itself.


2 years ago

I typically start out with a flat layout similar to the one above. Then, I add in the handle and the 2nd layer, and internals, then usually lose interest and do something else.