Introduction: Lego A2 Powerful Mini Crossbow

Picture of Lego A2 Powerful Mini Crossbow
This is the sequel to my smaller A1 crossbow. This crossbow is ALOT more powerful, because it can shoot 30+ feet (depending on rbs), can dent cardboard (keep in mind, this is lego, not sharpened knex), and is very accurate. The only downside is that this crossbow is larger than the A1, but it is still fairly small. It also has a new type of sight on it, which is kind of like the Ak47 type of sight. It makes it alot more accurate. The crossbow also has a new type of trigger, a system which uses 2 gears to fire. The crossbow fires 2x2 bricks, with a flat piece on top.

My website is at

Step 1: Bottom Add-Ons

Picture of Bottom Add-Ons

In this step, the handle and the trigger holder is made.

Step 2: Trigger

Picture of Trigger

The trigger and the pivot pieces for the trigger.

Step 3: Base + Attaching Add Ons to Base

Picture of Base + Attaching Add Ons to Base

Here we make the base of the gun, and we attach the trigger and the holder thing to the bottom of that.

Step 4: The Ends of Crossbow (RB Holders)

Picture of The Ends of Crossbow (RB Holders)

The 2 sections of the end of the crossbow.

Step 5: Another Thin Layer on Top, and the Back Part

Picture of Another Thin Layer on Top, and the Back Part

Read the title

Step 6: Firing Gear and Completion of Runway

Picture of Firing Gear and Completion of Runway

The gear that holds and fires the rubberbands is made, and the runway is completed.

Step 7: Sight (Optional)

Picture of Sight (Optional)

This is how to build the sight

Step 8: Ammo and Rubberbands

Picture of Ammo and Rubberbands

Shows the type of ammo, the rubber bands used.


Slurpee801 (author)2012-02-18

Just pointing this out but... None of these are really crossbows. =\. The definition of a crossbow is: A weapon consisting of a bow fixed crosswise on a wooden stock, with grooves on the stock to direct the projectile. These look like crossbows, but you don't really have a bow on there. Bow - a weapon for shooting arrows, composed of a curved piece of resilient wood with a taut cord to propel the arrow. So my point is... These are crossbow shaped slingshots. Not crossbows. Just sayin'. 

Bitterberry9 (author)Slurpee8012012-02-23

wow you are good at the copy-paste feature.

Slurpee801 (author)Bitterberry92012-02-28

I'm just amazing at everything in general. :).

speedracer425 (author)Slurpee8012012-08-26


speedracer425 (author)2012-08-17

When you install the gears you are pushing one gear into another forward causing the top gear to go back. What did I do wrong

smart8806 (author)2009-03-01

where's the list of all the different pieces you used?

Bitterberry9 (author)smart88062009-03-02

havent made on yet, i might soon though

you are awesome how old are you and do you have a clubpeinguin if you have please be my friend my user name is dannypalmer

Reuben37891 (author)2011-11-05

thanks i made it and god its powerful! ive made some changes though. ive got a longer trigger and made different iron sights. again, thanks.

speedracer425 (author)2011-07-27

i don't have these wing pieces or the 4x6 pieces

speedracer425 (author)2011-07-26

the thing is awesome but I trying to get on of those circular spiky things.:(

just found one!:)

Ideal_Ideas91 (author)2010-11-13

why not adapt this to shoot pencils instead of lego blocks?
Just a little carving with the pencil eraser and you got an arrow.

Doctor Freeman (author)2010-06-17

on the step with the gears the small one doesent move is it intendended or not

RAM123 (author)2009-10-19

I made this one like, 5 months ago now.
It's awesome! Works really good.

legomman200 (author)2009-08-11

awesome I wish i had thought of that

knex gun instructions (author)2009-03-25

can you fire pencils

wangtrevor (author)2009-02-15

this gun is awesome but the gear where you put the rubberband is to small so i modified it by adding a bigger gear and moving stuff because i use 4 rubber bands and it goes like 5 feet!

Bitterberry9 (author)wangtrevor2009-02-15

i used that gear because it is the largest I have, maybe use thicker rubber bands, cause it went like 30 feet with mine.

oh wait, its not the largest I have, im not actually sure why I used that size gear...

wangtrevor (author)2009-02-15

does this sight work? i mean can you aim at target with it and hit the spot pretty close or is it just for decoration

Bitterberry9 (author)wangtrevor2009-02-15

half and half. It was originally for decoration (doesn't really look like it though lol), but it can usually hit where you aim (worst case its like an inch off), but it kinda depends on the rbs you use

wangtrevor (author)2009-02-15

For picture 7 you could've used bricks that were 1 thick not 3 1/3's

Bitterberry9 (author)wangtrevor2009-02-15

ya, you're right, I just built it originally like that.

wangtrevor (author)2009-02-14

Are the 2 holed blocks in step 2 picture 11 necessary? I only have 2. Next time you shouldn't use "exotic" blocks like those i happened to have 2 from this years FLL (those pieces are very hard to find.)

Bitterberry9 (author)wangtrevor2009-02-15

yes they are, because they allow the trigger to rotate at a certain area where it can mesh with the firing gear and, when pulled, let go of the firing gear. In the future, I'll try to design a mechanism without the 2 holed bricks (like the C3 I just made). In this case, you could probably try the one holed bricks, but I cant guarantee that they would work the way these do.

wangtrevor (author)Bitterberry92009-02-15

oh lolz i just didnt put one ill tell ya what happens and which one should i put 1 holed bricks the one in picture one or in picture 11

Bitterberry9 (author)wangtrevor2009-02-15

oh, I see what you mean. Picture 1+2 need the 2 holed bricks, but picture 11 doesnt really, I just used them to make the trigger more comfortable (so there want a big hole in it). You could use other pieces to fill in the gap. So, put the one holed bricks in picture 11

pls (author)2009-01-27

Firing a lego gun at a knex box, AHHHHH. Awesome crossbow none the less:)

bounty1012 (author)pls2009-02-09

utter betrayal lol

pls (author)bounty10122009-02-10


Bitterberry9 (author)pls2009-02-10

lol if you think this is bad, my new crossbow video is blasphemy.... i should have that instructable posted in a couple days

Bitterberry9 (author)pls2009-01-28

thanks lol i only did that cause I happened to have a spare box lying around

pls (author)Bitterberry92009-01-28

Don't worry about it.

apples!!!!! (author)2009-01-29

Lol you love legos....I actually tried to make a mag fed gun out of only bricks, snd it had a true trigger....then when I moved, I put it in a box and it was crossbow, though lol......

Bitterberry9 (author)apples!!!!!2009-01-29

lol that sucks

About This Instructable




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