Picture of Life size k'nex war cannon
Here it is the best of the best life size (or almost life size) war cannon. Yes I know there are lots of knex cannons on Instructables but this one is different from the rest. It looks like a cannon. It will shoot 60 - 70 feet with 2 rubber bands ,and will shoot though 4 pieces of paper. This does use ALOT of parts so I took the time to take a part count so you don't waste your time. It uses a more simple trigger Then IAC cannon but it(kinda) uses the same mech.

looks great
wonderful distance 60 - 70 feel with 2 rubber bands
will completely destroy 3 pieces of paper

uses a lot of pieces

Step 1: Part count


76 gray

70 red

37 yellow

27 blue

55 white

100 green


17 white

40 blue

44 yellow

58 purple

70 green

27 red

6 gray

11 orange


4 gray clips

8 small gears

I can't give a number of spacers. Because the number will differ for each person.

18 black hands

2 rubber bands
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This was the first of the cannons that i built about four and a half years ago on this site.

dude this thing rocks just built but the only down side is that is does not shoot good for me
I built 4 of this but i didnt bulled the wheels so i took the cannon pieces and attached the barrels to my arm and walked to into the libreary with it....
I built this and i tested out how far the projectile would fly so i put it in our drive way and pulled the trigger and the piece flew out and hit a moving car. The person stopped so i pulled the cannon behind are car and waited for him to leave.
Sypran6 years ago
cool, I'm gona build this and put a seige on the playground fort hahaha
good idea
im gonna terrorisate the mcdonald's playground=D
sounds fun.... can i join in?
That's gonna be fun!!
Let's both build one and shoot children?
i would but im 3 years too late :3
do u have to use the flexi-rods for the barrel
skyfaller4 years ago
This is good!

You should check out I_Am_canadian's knex heavy cannon.
Brad G4 years ago
Modded this quite a bit, ALOT less skeletal it looks pretty awesome ;) fully metallic shoots a bigger projectile (like IAC Cannons) and the end of the barrel is modded a little, i will try and get pictures thanks for making this great cannon ;)
instruct395 years ago
you need cannon ammo not little tiny ammo u cant find after shooting it, other than that very cool! 5*
clader15 years ago
dude it doesn't go 60-70 feet. you lier i shot it it went 150-200 feet !!!!
lol XD its really cool!
Furloy5 years ago
 4.5 stars, it skeletonish
I gotta say it looks good. 4.5*
i think that it is really cool but i do agree that it could use more reinforcement. I think that it would be cool if you made it a breech loading cannon if you made any mods to it.
knexkrazy (author)  codemaster25906 years ago
Thanks! I'm working on a second version that has more parts, but it takes a lot of pieces.
Umm? "second version that has more parts, but it takes a lot of pieces." LOL
so how far can this canon shot 70 80 feet or is it a low range gunthat can only shot about 20 feet
lol it say right there /\ /\ /\ /\ /\
Skreetsha6 years ago
Cool! A bit skeletony but, it probably functions as it looks, and that would be great :D 5 stars!
Oh yeah... Nice wheels Nice pictures.
alfpwns6 years ago
builder9686 years ago
pretty cool. I know i dont have any howework tomorrow evening;might build.
then again, i might not. might build on sunday(saturday i have a friend's party).
arrow shot6 years ago
nice, but i hardly believe that cannon barrel is life sized...maybe provide us with a picture? of the real thing>?
knexkrazy (author)  arrow shot6 years ago
This is the cannon I was modeling it after. Of course I can't go true life size without using a TON of parts. But, I called it life size because it is VERY big and looks pretty much like the real thing.
Yeah, it actually is almost life sized...If i had to guess, i would say 5/8? Havent built this yet though, so idk...too many peices for me XD
apples!!!!!6 years ago
Now I don't know if I want to work on the one I wanted to....
yerjoking6 years ago
Wow, I'd just love to sit at the back then fire it at someones face, they'd get owned lol.
Master_Zane6 years ago
Sweet! Looks Great!
knexkrazy (author)  Master_Zane6 years ago
uguy6 years ago
Life size?
knexkrazy (author)  uguy6 years ago
I said in my intro that it was "almost" life size. Actually, it isn't too much smaller than some cannons, but obviously not "real" life size.
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