Barackuda

Introduction: Barackuda

About: Just an aging K'nex launcher builder

It's been years since I've shown the first version of what would be the Barackuda and now I've finally gotten proper instructions. Long story short, it's a bolt action launcher with a compact drum magazine. While I had hoped to turn it into a competent war launcher with enough work, it never performed quite as well as I was hoping, so instead the novelty is purely in how compact it is.

Just a reminder, I've setup a blog here where I post most of my activity other than instructions. Anyway, let's move onto the instructions.

Parts list:

Connectors:

  • Dark grey/purple one-slot: 87
  • Light grey/light orange two-slot: 21
  • Orange/brown two-slot: 34
  • Red/granite three-slot: 41
  • Green four-slot: 8
  • Yellow/grey 5-slot: 76
  • Blue 7-slot: 2
  • White/black 8-slot: 3

Rods:

  • Black/clear: 3
  • Tan: 2 (Ideally, all red rods should be tan if you have enough)
  • Red: 11
  • Blue: 10
  • Silver/white: 72
  • Green/black: 157

Misc:

  • Sockets: 2
  • Ball joints: 2
  • Dome halves: 2
  • Chain connector: 1
  • Blue caps: 6
  • Tan locks: 15
  • Silver spacers: 9
  • Blue spacers: 28
  • Black Ys: 48

Bands:

  • #64s: 2+
  • Smaller bands (e.g. from newspapers): 3

Step 1: Main Body - First + Second Layer

The Barackuda was designed to be compact, so the main body is based on the Oodassault 3's design, giving it just enough durability for an otherwise slim barrel. This is one of my more complicated designs, so I got a plethora of pictures, hopefully allowing anyone to build it without much fuss.

Step 2: Main Body - Inner Layer

Here we start the barrel and the feed ramp. This should all be pretty easy.

Step 3: Main Body - 4th Layer + Trigger

I had to figure out something unconventional to allow a sear to fit in this tiny pack that still maximized striker length as much as it could.

Step 4: Main Body - Other Internals + Handle

Here we finish up the feed ramp, magazine catch, and start the handle

Step 5: Main Body - Outside Layer + Rear Sight

Here we finish up the outside of the main body and add the rear sight. The rear sight block will hold the front of the striker guide.

Step 6: Handle Details

And here is how we finish up the handle. I tried to make it a little more comfortable than most handles but the nature of K'nex and their blockiness limits the ergonomics a little. To aid in the compactness and structural stability, it's a thumbhole handle-stock design.

Step 7: Stock - 1st and 2nd Layers + Some Internals

The stock is, I'll be honest, a little rough given the design of the main body. It's not attached conventionally. The stock is designed to be rail for the bolt to travel within to facilitate quicker charging of the launcher.

By this point, you can get a little creative with how you want the stock to look if you're experienced. Just be careful with the parts connecting it to the launcher.

Step 8: Stock - Middle Layer + Striker Guide

This launcher didn't use to have a striker guide, but it was one of the improvements I knew I should make. Due to the unconventional stock attachment, I had to make an equally unconventional striker guide attachment point. It's attached pretty securely to the stock.

Step 9: Stock - 4th and 5th Layer

And now we'll finish up the outside of the stock. Again, if you're feeling creative, you can adjust the design however you want as long as you end up keeping the main attachment points.

Step 10: Connecting Stock to Launcher

Short but important step. Again, the stock connection method is very unconventional. A lot of the weight is being directed into the bottom of the handle. I try to prevent some side-to-side wobble by connecting the stock at the top on the outside as well. Still, it won't be the sturdiest stock connection, so I don't recommend handling the weapon via the stock.

Step 11: Bolt Handle

Ideally, if you have extra tan rods available, use those instead of red rods for extra strength.

Step 12: Finishing Trigger and Adding Bolt Pin + Handle

More quirkiness in design due to compactness. The trigger slides up against the bolt pin and keeps it in position. The bolt handle connects loosely to the bolt pin.

Step 13: Striker, Striker Guide, and Bands

Here we finish setting up the launcher to fire. Unfortunately the way the bands are setup makes them difficult to replace. Getting them through the spacers can be tricky, but you'll get used to it in time.

Step 14: Magazine Internals

Here is the magic of the drum magazine. The dome pieces are important for keeping the rods at just the right distance to help them feed reliably. The ball joints are also important for being just the right height to push them reliably.

Step 15: Magazine Shell

Sorry if this is a little confusing. Basically you repeat the same steps 6 times to complete the majority of the magazine shell. Again, ideally, if you have them available use tan rods in place of red rods. I only had two so I figured the best place to use them was the top of the magazine.

Step 16: Finishing Up Magazine

These are the last bits to make the magazine work.

Step 17: Loading and Operating

This is complicated enough I decided to just make a video for it. Follow along for proper handling and operation of the launcher. Don't do anything reckless and have fun! Let me know what you think and post pictures of your own modified versions.

2 People Made This Project!

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28 Comments

0
Fastest Boi
Fastest Boi

Tip 3 months ago

This is trash it blew up in my face first time after 2 hours of work.

0
Lucas The Boss
Lucas The Boss

11 months ago

Can't believe I'm just now seeing this, I remember years ago trying to replicate it from the forums you had posted about the drum mag design. I never successfully came up with my own design that worked, I may have to dig out my knex buried in the closet and build it. Man, I miss this community we had here.

0
rileygeorgecook
rileygeorgecook

Reply 4 months ago

I've just started making knex guns and i've just finished making a turret pistol that im really happy with and id like to make this but im not to fond with the idea of breaking my knex pieces because i don't have loads of them so does this use any broken pieces

0
TheDunkis
TheDunkis

Reply 4 months ago

I don't believe it used any, not according to my parts list anyway.

0
Creater0479
Creater0479

Reply 4 months ago

Hi TD I cant believe your still active

0
rileygeorgecook
rileygeorgecook

Reply 4 months ago

Great, ill look forward to building it then because i love the mag design

0
TheDunkis
TheDunkis

Reply 11 months ago

It was a bit out of the blue. Can't believe it's been just about two years since I posted it either. Time keeps moving on. It's disappointing that I didn't manage something like this earlier. I was so proud to get this sort of magazine working, even if it's just a novelty. Even Mepain brought the K'nex out again to build it (his stock looks a lot better too). Let me know if you do decide to build it, or anything really. I don't build much anymore, but I'm always excited to see what people still come up with. Hell, now I'm getting ideas of how to improve this, maybe I'll rebuild it.

0
Lucas The Boss
Lucas The Boss

Reply 11 months ago

Yeah, it's crazy to think it's been over 4 years since I even built anything. I guess between working and pursuing an engineering degree in college, there's not enough free time to build anymore. I've still got my air-powered knex rifle that I believe I told you about years ago when I was still building it. Technically speaking Its the furthest shooting knex gun ever made, however, I don't believe it really counts as the entire barrel and valve mechanism is not made of knex and can be shot without the knex shell that makes the body of the gun. I did develop a "new" round that I don't think anyone has made that consists of a blue mini knex finammo round that has a 3D printed sabot that I drew up in creo that enlarges the outside diameter to a regular knex rod (I could send you the CAD file if you're interested in testing it). Shooting those rounds with a CO2 bottle was achieving over 300-yard shots but again I don't believe really counts towards the record due to the nature of the gun. I thought about posting it here but it seems Instructables wants a full instructional guide nowadays so I doubt I will. I included a picture just for the hell of it. I've really been itching to revisit that concept of a true bolt action slingshot like that crossbow I posted years ago.

fullsizeoutput_d6.jpeg
0
TheDunkis
TheDunkis

Reply 11 months ago

The launcher looks nice, I'm fond of the thumbhole stock. K'nex makes for a useful building tool toward other projects, but it starts getting "unfaithful" when we introduce other technologies to our projectile launchers. Still, it'd be nice to have pieces that are, y'know, actually designed for being projectiles and don't spin out after 10 feet. Actually, now that I think about it, something I'd want to try is using mini to normal transition rods with tape fins wrapped around the smaller sections such that they could fit down a normal K'nex barrel. I don't know how much difference it'd make, but it could potentially offer a way to make an easily mag-fed, repeating, finned ammo launcher.

Unrelated note, I find it interesting how many builders ended up in engineering. I'm of a less common breed that pursued computer science. I think it shows in how our building styles differed.

0
Creater0479
Creater0479

Reply 11 months ago

Wow. You are still here!

Can you tell me how to make an ible that will attract lots of views please?????

0
underswap sans
underswap sans

Reply 11 months ago

what a noob

0
Creater0479
Creater0479

11 months ago

Rifles are not realy my thing, but oh well it is good for what it is.

0
carworld11
carworld11

1 year ago

I thought the knex gun makers were all gone until I saw the name!

0
Insaneknexguyisback

Awesome gun nice to see your still in the community

0
crestind
crestind

1 year ago

First time I've read a K'nex gun Ible in a decade. Bittersweet seeing a lot of people I remember here.

Very cool gun, a drum mag! Amazing how well the drum is integrated, with its irregular parts.

0
TheDunkis
TheDunkis

Reply 1 year ago

Well if it ain't Mr. KI himself. What brings you round these parts again? Kinda funny how this ible served as a reunion place of sorts for the older K'nexers.

Thanks! I didn't really stop to look at all the things I learned over the years and looking at this now I realize how full of nonconventional building methods it is. The drum was certainly the exciting part. Getting it to attach to a launcher, let alone in a removable fashion was certainly a challenge.

0
crestind
crestind

Reply 1 year ago

Nostalgia for simpler times :) Happy to see you are still posting, with the same avatar no less lol

0
DJ Radio
DJ Radio

2 years ago

Dang dude, you’re still holding it down after all this time. Mad respect to you for that. I don’t even know why I’m on here at this particular moment but at least I can still kinda see what’s going on despite all the site changes.

0
crestind
crestind

Reply 1 year ago

Can't believe they wiped everyon's profile comments.