This is a simple crossbow using some K'NEX and 1 rubberband. It's fast, easy, and it shoots a K'NEX projectile really fast
Step 1: PARTS
For this project you're gunna need:
1-small green rod
8-small white rods
Step 2: FRAMEWORK 1
Use the picture provide to help you build the first part of the frame.
Step 3: FRAMEWORK 2
Once again make these 2 peices using the picture.
Step 4: Finishing the Frame
Attach the 2 pevious peices and the red rod.
Step 5: Firing Mechanism
Attach the rubberband to the 2 grey peices like so.
Step 6: Finishing Up
Attach the firing mechanism to the top of the frame so it looks like the first picture.
Step 7: Firing
Now you're ready to fire. For ammo you can use any K'NEX peice with a hole than you can slip over the rod and that has some plastic on top to catch the rubberband. In the picture im using a red connector because they seem to work well but it really dosen't matter. Thanks for viewing my instructable, this is my first one so any comments on what to do differntly next time would be helpful.
Step 8: MOD
I have recently discovered that when the first rubberband i use snapped because it was too worn out, i replaced it with the same kind of rubberband but this 1 was more powerful so, when i went to fire the frame came apart. I have made a mod that stops this from happening by adding 2 more rubberbands and 2 white peices. I have also discovered that the grey clips are the best ammo to use. After i made my mod and tested it with the grey clip this thing was shooting so fast it bounced off the wall from about 20 feet back, came back and hit me. I also went outside and shot it and it measured at about 42 feet with wind. This weapon is devastating at point blank (0-6 ft.) Try shooting 1 of your friends...or enemies. Also on the picture in the firing step i have it flipped the wrong way so flip it over when firing also when using the red peices they should be facing downwards with the hole at the top. I hope this clears some things up