R-8 Knex Grenade

This is a fairly simple knex grenade that is pretty powerful for its size. It only uses 12 pieces and 2 rubber bands. Sorry if this is anyone else's, it might have already been made due to its simplicity...

This will NOT blow up when you have the second rubber band (the purple one in this picture) on, take it off to activate it!

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Step 1: The Pieces

Red connector x 8

White connector x 3

Blue rod x 1

Rubber Band x 2 (if you try it with 1 it will be very hard and it won't have a safety mechanism)

Step 2: Putting It Together

Okay, tke the red connectors and attach them to a white connector like so. (pic 1)
Then, wrap a rubber band around all of the red connectors. (pic 2)

Next, add the other two white connectors to the top and bottom of the device. (pic 3)

Finally, place the grenade on top of the other rubber band and pull the rubber band up through the spaces between the outide rubber band and the white connector on opposite sides. Thenput the blue rod through both loops. (pics 4 & 5)

Now you're done!

Step 3: Priming and Detonating

To prime the grenade, simply take off the outside rubber band CAREFULLY. Now it's armed.

Chuck on the ground for best power! Have fun!

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    9 Discussions


    9 years ago on Introduction

    This is a good design, but if you use a second blue rod + elastic and space the two on either side of the central hole in the snowflake pieces, not only do you gain Area-of-Effect but you can now load it into a launcher!  Perhaps the outer band could be snagged/removed during launch so it does not explode during initial acceleration?

    1 reply

    Reply 9 years ago on Introduction

    Remove the elastic band before you load the grenade launcher and you will have a knex shot -gun because the grenade will explode while leaving the gun.


    10 years ago on Introduction

    no offence but it kinda sucks it di get bout 5 foot ragnge though so i would say 4.5*

    Nevermind, that was easy. It's bigger and looks very different. It has tons of fragments by it's self plus you can add more to it. I just posted it! Also, you don't even need rubberbands! ( But it makes it more powerful if you use them. Hope you like it!