Introduction: Knex Crossbow

Picture of Knex Crossbow

Fires up to two shots at once, and has adjustable power. This design, with less power, can also fire 'spodies at short range.

Step 1: Pieces



blue spacers-16
sm. wheels-2
black connecing pieces-12
rubber bands-8 or more
string-about 1 foot

*need one to make one shot*

Step 2: Connecting Pieces and Trigger

Picture of Connecting Pieces and Trigger

The two connecting pieces should be opposites (as shown).

Step 3: Ammo-locking Thing

Picture of Ammo-locking Thing

enter longer description for this step

Step 4: Assorted Other Pieces

Picture of Assorted Other Pieces

The last four are used to adjust the power.

Step 5: Arms

Picture of Arms

Make two opposite arms, and tow pulleys (to be used later).

Step 6: Put Pieces Together

Picture of Put Pieces Together

enter longer description for this step

Step 7: Attach String and Rubber Bands

Picture of Attach String and Rubber Bands

enter longer description for this step

Step 8: Attach Arms and "bowstring"

Picture of Attach Arms and "bowstring"

The bowstring is made by connecting about 6 rubber bands together on a string, and making a loop by tying the two ends together.

Step 9: Loading the Crossbow

Picture of Loading the Crossbow

This may be difficult at first, so point it downrange, so to speak. Two shots can be loaded side by side.

Step 10: Adjustable Power and Sharpened Ammo

Picture of Adjustable Power and Sharpened Ammo

Adjusting the power is done by moving the arms forward on their hinges, and locking them in place using the four extra pieces.

A pencil sharpener easily sharpens the tip of the ammo, but the blade dulls faster.

*Note: Caution is strongly suggested when using sharpened ammo. It is not recomended to use sharp ammo on your first try, or at anything living.

*Also note: If you didn't figure the first warning out already, it is suggested that you permanently dismantle the crossbow.


babygotback (author)2010-08-24

looks really cool

knex freak101 (author)2008-03-02

thats pretty much the same as gorkem's crossbow.

Whaleman (author)knex freak1012008-03-25

'Cept that it was posted about 7 months before.

KnexFreek (author)Whaleman2009-09-23


antonk (author)2008-07-12

looks like a bow

(your name here) (author)antonk2008-07-12

The bow part is kind of for show, and to make it a crossbow (not a spear gun).

ojochris (author)2008-04-20

looks like a wrist rocket to me...

Dragon X (author)2007-08-04

There is too many knex cross bws pistols and rifles

phlorgan (author)2007-07-20

u r so sad... this is depressing. if all ur gonna say is that then bugger off!

phlorgan (author)phlorgan2007-07-20

crossbow looks good but im not into (cross)nows that much and am having a break from guns for a while... perhapse mod my rc car...

Danny A (author)2007-06-18

Will you stop typing this. it is annoying.

Yaano (author)2007-06-05

if you think thats cool wait till you see my bow literaty its a bow not a crossbow im 13 and i have 5 bows 1 dimond 1 mathews 1 hoyt and the other 2 are to small i will post bit idk if my mom will let me

knex noob (author)2007-05-22

looks cool, just how far does it shoot?

At least 20 ft.

Knex Lego Maniac (author)2007-01-09

looks good how far does it shoot?

can u check out my gun its not that good but still please

It depends, but using standard rubber bands it can shoot at least 20 feet.

bunduk (author)(your name here)2007-02-05

I love it!!!

Kaiven (author)(your name here)2007-01-12

hey, could you make a heavy srossbow that shoots only one? i think i like single shots better for some reason...

(your name here) (author)Kaiven2007-01-13

This model can shoot only one at a time. It just has the ability to shoot two or one at a time.

Kaiven (author)(your name here)2007-01-15

oooh...nice. ill try to post a picture if i make it.

cool never tired making a bow what r some of the advantages if any over a gun?

More control (like a manuel versus automatic), the readily-adjustable power, ability to fire heavier ammo (to lob it) or costom ammo without redesigning the launcher, and, of course, style. I also think that the direct transfer of energy, unlike a firing pin, is more efficient, giving the ammo more power per rubber band.

RazerM (author)2007-05-15

This is a great design and put a dent in my wall. I modified it a lot by using grey rods instead of red rods; made the bow arms longer and I also changed the bow to swivel to the back to make loading easier, then the bow can be pushed to the front and locked into place.

Wicky (author)2007-05-09

I've made a cool crossbow aswell and i've submitted the instructable. In about 4 days I will add pictures of the trigger aswell.

knexballer08 (author)2007-04-18

looks good, i'll try it out

crapflinger (author)2007-01-09

now if someone could figure out how to make a compound crossbow (though your method for adjusting the tension is nifty as well)..

I have developed a version of this crossbow that uses pulleys and only one large rubber band.

planning on posting it? i think that would qualify as a "new design"

Mepain (author)2007-01-09

how do you make the bowstring?

(your name here) (author)Mepain2007-01-09

By tying rubber bands together, and use string to finish the loop.

oodalumps (author)2007-01-09

I like your stuff, always original.

crestind (author)2007-01-08

A great design! More than a rubber band strapped to a horizontal bar and labeled a crossbow.

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