Compact K'nex Wheel Crossbow

This is a very accurate crossbow. It can easily shoot over 40FT and is very resistant to breaking, but it takes a lot of pieces to make. There is always at least one picture per step, to make sure you see it all right. There is not much on each step, so it looks like there is a lot of work, but there is actually not. In the steps while creating a new part, I will give a few views if it is confusing. In the steps where you attach parts, first it will show the whole thing in the first picture and then zoomed in on the attached part on the second picture.

Step 1: Pieces

White: 2, yellow: 15+, purple: 2, Green: 6, red: 12, orange: 23, light grey: 1, gray: 31
Red: 6, yellow: 6, dark blue: 6, white: 21, green: 28
Semi-thick rubber band: 1, big wheels: 2, locks: 2, nubs: 2, blue circles: 17
Total: 183+

Step 2: Make the Handle

Pieces needed: Red rods: 2, white rods: 2, grey connectors: 7, orange connectors: 2

Step 3: Make the Scope

Pieces needed: dark blue rods: 3, white rods: 2, green rods: 6, orange connectors: 3, white connectors: 2

Step 4: Attach the Scope to the Handel

Snap the 2 orange connectors on the bottom of the scope to the red rods of the handle and the green rods on the end of the scope to the loose grey connectors of the handle. You will have to decostruct part of the handel to slide part of the scope on.

Step 5: Make the Joint

Pieces needed: dark blue rods: 1, green rod: 2, red connectors: 1, green connectors: 2

Step 6: Attach the Joint to the Handel

The green connectors of the joint connect to the red rods of the handle.

Step 7: Make the Firing Piece

Pieces needed: dark blue rods: 2, grey connectors: 4, yellow connectors: 2

Step 8: Attach the Firing Piece to the Joint

First, attach the green rods of the joint to the yellow connectors of the firing piece. Next, sap the red connector of the joint to the open dark blue rod of the firing piece.

Step 9: Make the Sliding Bar

Pieces needed: yellow rods: 2, white rods: 1, green connectors: 1, light grey connectors: 1

Step 10: Attach the Sliding Bar to the Joint and Firing Piece

First in picture 1, slide the tiniest bit of the yellow rod of the firing bar in the joint. Second, in picture 2, Hold 2 blue circles in the middle of the 2 green connectors of the joint, then, slide the sliding bar through. 3rd in picture 3, slide the sliding bar all the way through the firing piece.

Step 11: Attach Pieces to the Sliding Bar

Pieces needed: grey connectors: 1, blue circles: 3

Step 12: Make the Runway

Pieces needed: red rods: 3, white rods: 2, green rods: 12, grey connectors: 1,orange connectors: 1, red connectors: 2, yellow connectors: 8

Step 13: Attach the Runway to the Firing Piece

Attach the green rods on the end of the runway to the yellow connectors and the loose grey connectors.

Step 14: Attach Pieces to the Runway

Pieces needed: grey connectors: 8, orange connectors: 6, blue circles: 2

Step 15: Make the Bottom Stregnth

Pieces needed: red rods: 1, green rods: 2, red connectors: 2, and all your ammo (extra yellow connectors)

Step 16: Attach the Bottom Stregnth to the Runway

Attach the bottom strengths end green rod to the runways open yellow connector and the bottom strengths red rod to the runways open bottom orange connectors.

Step 17: Make the Rubber Band Support

Pieces needed: yellow rods: 4, white rods: 6, green rods: 5, grey connectors: 8, red connectors: 3, purple connectors: 2, yellow connectors: 5, rubber bands: 1, blue circles: 10, locks: 2, nubs: 2, large wheels: 2

Step 18: Attach the Rubber Band Support to the Runway

Attach the yellow rods on the end of the rubber band support to the orange connectors on the runway.

Step 19: Make the Top Support

Pieces needed: red rods: 1, white rods: 8, green rods: 1, grey connectors: 2, red connectors: 2, orange connectors: 11

Step 20: Attach the Top Support to the Rubber Band Support and the Runway

Snap the orange connectors on the top support to the runway's red rod. Attach the green rod of the top support to the rubber band support's purple connector. Then, your knex wheel crossbow is completely made. Because 3 parts are being connected, I did not take a picture of all of it.

Step 21: Loading

1 (picture 1): get a yellow connector and lock it in the firing piece, sliding the sliding bar through its hole. 2 (pictues 2 and 3): pull the rubber band (both parts of it) back onto the yellow connector.

Step 22: Firing

You should do this outdoors. Warning if you shoot it at anything hard it could break the yellow connector. 1 (picture 1): look through the scope and line up your shot. 2 (picture 2) : pull the sliding bar out of the yellow connector and watch it soar through the air.



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    21 Discussions


    6 years ago on Introduction

    You are the George Lucas of instructables. Very nice instructable , well done.


    9 years ago on Step 22

    you should try to change the handle. I did it myself but try to do it yourself it  is easy and simple. it will be better


    10 years ago on Step 21

    I built this crossbow but it only shoots around 1 1/2 meters not 13 1/3 how does this happen?

    1 reply
    Super ShooterAnidion

    Reply 10 years ago on Introduction

    It depends mostly on the rubber bands. It could also be shooting almost nowhere if pieces are in the the way of bullet when it fires. try taking one layer of the grey connectors on the rubber support off.


    10 years ago on Introduction

    Finally got around to making it. It's amazingly awesome and I will probably never take it apart!!!