Introduction: K'nex Landmine/ Grenade

Picture of K'nex Landmine/ Grenade
This is my knex land mine that shoots out shrapnel when a trip wire is pulled. i decided to use the simple block trigger idea and make something creative instead of a gun (although you may consider this a gun, because it shoots knex pieces) any ways, you can use pretty much any knex grenade that fits itself together loosely, like mine(you just have to put a white rod on it).

Step 1: Firing Mech

Picture of Firing Mech

This is the Firing mechanism that makes the grenade explode. since the bullet doesnt go all the way in the barrel, it smacks it and makes the grenade blow up. Make sure to tape the firing pin. adjust the rubber bands so that if you pull it back, put it at a 45 degree angle, load in a white rod, and shoot it, it should go 15 to 20 feet. here i used 3 thin rubber bands.

Step 2: Stand

Picture of Stand

this is the stand that holds everything up. make sure to put something small but semi-heavy on the leg opposite of the trip wire. (in my case, a rock band drum pedal.)

Step 3: Grenade

Picture of Grenade

this is easy, just build it. you can use any knex grenade that fits together loosely like this just ad a white rod

Step 4: Tie to a Doorstop or Some Nail Sticking Out of a Wall or Something

Picture of Tie to a Doorstop or Some Nail Sticking Out of a Wall or Something

I suggest tying it to a door stop with string and when someone opens the door it goes off. its less noticeable if you put it there and gets you by surprise.
to load it, pull it down the firing pin and load in the grenade. when the trip wire is pulled, it goes off and scatters shrapnel everywhere.


jmoore11 (author)2011-08-31

This worked great for the grenade I used, it exploded at chest height and actually hurt a bit. The only thing is that the trigger where the string is attached should be lengthened to get more leverage. And on ceramic I needed a weight to stop to door from pulling it away. Great booby trap.

NGPhil22 (author)2011-03-27

I have a better grenade for this. Instead of spreading over the floor, the fragmentation shoots up and around. I will see if I can get a picture. I have also modded a little bit to it to make it more stable. I also made it so that when you tug on the wire, a pin removes itself so the wire doesn't trip anyone. Thank you so much for the basic design. Very good for pranks

Ikedog1995 (author)NGPhil222011-03-30

Very cool. Yeah this design is VERY basic, so improvements are definitely needed. Thanks for building

danbaha (author)2010-08-04

This is the so cool!

coleslaw3 (author)2009-04-11

Can i Sharpen Or will It Mess IT up

master of knex (author)coleslaw32010-07-30

yah good idea

Dante9030 (author)2009-07-07

you have rockband!

ol987986 (author)Dante90302009-08-13


Dante9030 (author)ol9879862009-08-13


ol987986 (author)Dante90302009-09-12

lol! i have gh world tour i used that instead.

ol987986 (author)ol9879862009-09-12

that dont break it proves (kind of) that gh is betta than rockband cos rockband is a cheap, crappy immitation. thanks for listening.

mberg (author)ol9879862010-06-23

rockband sucks. medium feels like expert. the thing is completly stupid. i use my rockband drums on Guitar Hero 5

ol987986 (author)mberg2010-06-30

gd on u

Ikedog1995 (author)Dante90302009-07-08

mhm, now the pedal is broken in 2 places i have it held together with a ruler and tape

Dante9030 (author)Ikedog19952009-07-08

lol mine is broke right in the middle

ooglie_booglie (author)2009-08-29


knexman45 (author)2009-06-21

awesome! 5 starz :-)

Ikedog1995 (author)knexman452009-06-21


barrett50cal (author)2009-05-29

u can also just put a white rod in and lay it down on the ground and aim it at the door...

lilnorm123 (author)2009-05-27

if you stick the point of a red connector in the shaft it will fire the way it is pointed!!!

knexguner929 (author)2009-05-23

i did it on my sister

knexguner929 (author)2009-05-23

I used invisible fishing wire BTY 5 *****

An Villain (author)2009-04-30

i have an interchangeable head for this that fires spacers EVERYWHERE and my mom wonders how there are little blue rings in her lampshades

the_builder (author)2009-03-08

Wow! This thing is awesome! I put one in the doorway to a bathroom in my house, and it scared the crap out of my dad. 5 stars!

An Villain (author)the_builder2009-04-16

i built two and set them both up in the bathroom and whenever someone would go in i would just wait for them to come out then reset it.

Ikedog1995 (author)the_builder2009-03-09

awesome! meh loves teh five stars! lol

b00mstix (author)2009-03-26

omg this is the best thing ever even my mom was inpressed nice work!

knex obsessed (author)2009-02-23

can someone tell me a way i can keep it held down as i don't have rockband or guitar hero BTW cool landmine

b00mstix (author)knex obsessed2009-03-26

use a tuque as a base skirt or maybe use tape :) hope this helps

Ikedog1995 (author)knex obsessed2009-02-24

You don't need to use a Rockband pedal, I just used it because it was close to me and it worked. If I didn't have one, I would use maybe a book opened up a little and put on the ground to make a triangle and stick the cover (hardback) into a prong on one of the yellow connectors. or maybe I would use a weight.

knex obsessed (author)Ikedog19952009-02-25

ok thanks for that and btw i am thinking of making 2 of these on at either side and with string then bam also mine goes well high lol

Ikedog1995 (author)knex obsessed2009-02-25

thats a great idea. i was just looking around instructables and i never saw a mine with a tripwire on it so i just posted it. mod it all you want and post it even if its good enough. i wont care it only took me like five minutes to make anyways haha

knex obsessed (author)Ikedog19952009-02-26

hey can you check out my grenade pleaz and comment thanks

bannana inventor (author)2008-07-30

Very cool idea!!!



Pbyrd (author)bannana inventor2009-02-17

No, actually Rockband 2 rules.

*cough* not really *cough*

cool idea though.

I KNOW!!!!

pikathebudgie1234 (author)2008-08-25

cool1i made it for myself and what does it look like on the front side of the door???

it looks the same its pretty much symetrical on both sides except for the block trigger

Undermig (author)2008-08-24

im trying to get my sister but it aint possible... i got a good plan that actualy works. #1 take off the 2 red rods infront to hold for yelow ones.#2 take of the 2 red rods at the back to suport for 2 greys. #3 tie the string to the door so when it opends POW it explode Mwuhahaha o ps dont furget ure rock band waight ath the back so it cant failed!!!

Undermig (author)2008-08-23

thats like your best instructables... LOL ns

Undermig (author)Undermig2008-08-23


necropolian (author)2008-08-01

if any person would replace the video with a black square, no one would notice.

bounty1012 (author)necropolian2008-08-06

thats ok ill make a video for it

SeMi_AuToMaTic (author)2008-07-30

cool 4 stars


I_am_Canadian (author)2008-07-30

"A cup to hold shapnel or goodies or whatever" LOL

About This Instructable




Bio: I like video games a lot. Mostly guitar hero and rock band. I love the computer too. I like to go outside though. I'm ... More »
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