Here is a video which features a fully working crossbow built out of legos and rubber bands. The rubber bands are across the front to create the tension on the bow. Additionally there seems to be some rubber bands on the back area holding the stock of the crossbow togather. Lastly it seems like he has some kind of pump system for launching the bolt but it could be gears instead. In any event he loads the bolt in and fires a couple times at a metal paint thinner can. The point of the bolt pokes a hole in the can but the bolt itself doesn't stick.
Here is a video which features a fully working crossbow built out of legos and rubber bands. The rubber bands are across the front to create the tension on the bow. Additionally there seems to be some rubber bands on the back area holding the stock of the crossbow togather. Lastly it seems like he has some kind of pump system for launching the bolt but it could be gears instead. In any event he loads the bolt in and fires a couple times at a metal paint thinner can. The point of the bolt pokes a hole in the can but the bolt itself doesn't stick.
