Make a K'nex crossbow thingy using 4 2- way orange or black connector peices,2 yellow or gray stick peices,1 3- way connector, the biggest stick piece you have, and a rubber band.
Step 1: launcher
Take the orange or black connectors and the yellow or gray stick pieces. Connect the sticks using two of the connectors, so they are horizontal, and slide them to different sides of the sticks. Attach the other connectors normally to the stubs on ONE END ONLY. Complete the launcher by adding the rubber band underneath the connectors on the stub, and up to the top, so that the rubber band stays.