Knex Rocket That Really Launches


Introduction: Knex Rocket That Really Launches

About: I have moved on to better things...aka YouTube. So I will most likely not reply to any comments, sorry for any inconvienience. If you have important questions, you can go to my youtube channel (MagmaRhino) a...

This is a Knex rocket that actually launches using 4 large rubber bands. It is very simple and uses few pieces. It flies about 20 ft. Watch this video for proof. Please rate. Check out my new cannon.

Piece count (based on original colors)

red-28(n.b. mine are all green)

white snowflake-3
blue 3D-5
purple 3D-29
gray 1 slot-8
gray 2 slot-4

4 large rubber bands


Step 1: Rocket

This is the projectile shot out of the base.

Step 2: Base

The Rocket shoots out of this.

Step 3: Adding the Rubber Bands

You place each of the rubber bands around the white peg at the top. Then you add the rocket. Finally you pull down the rocket on to the rod and release it. Watch this cool video to see the launch.



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    i made it and it goes 60 feet in the air but i modified the structure

    i built this and i loved it so i thought i would improve it so i made a rocket three foot six and it didnt work but i made other big ones that were big and they worked

    could I possibly make it taller and tie rubberbands together to make it go higher? or would that make it collapse??


    Isn't this just a vertical catapult?

    8 replies

    Maybe so, but aren't most K'Nex "guns" really just catapults as well? (Nice-build, number-boy.)

    yes but mostly just cannons and snipers are catapults just so you know

    acctually, no they are not. they are crossbows to an extent. a catapult uses a slingshot mechanism or a swinging arm linked to a weight (trebuchet). Knex guns are crossbows, in that they use a blocker (trigger) to hold back a bolt which holds a projectile in front of it. when the trigger is pulled, the potential energy is released throwing the projectile forward.


    So the "block trigger" that certain K'NEXers moan about is simply something that blocks the movement of the projectile? I just learned something new about K'NEX...

    However, true crossbow triggers retain the string, and the elastic PE in all bows (cross, long, compound and ballistae) is stored in the bending of the arms, nor the elasticity of the string (which is actually inelastic).

    Yes - that is a block trigger, and that is true...

    And the only true crossbow on this website is the one by Mepain called huge knex crossbow.

    yes thay are so dont be so annoying uguy

    did you know that you can put in the bischoff system so it can have a trigger :D

    2 replies

    or you could put the mec from the brickster LDS or i_a_c 's heavy cannon mec on it

    built then turned it into a mortor 60FEET RANGE ON MINE!!!!!!!!