it depends how many different simple machines you want to put in it, but some things you might want to consider are wheels, slides, pulleys, levers etc. for example, u could but marshmallows at the top of a chute that is tied so it is horizontal. then something could cause scissors or a knife to cut the string, which would let the chute fall, and with gravity, the marshmallows would fall out. you could add a ton of other simple machines before that to make it more elaborate. some important thing you'll need are duct tape, nails, hammer, saw (if using wood), and screws. good luck and have fun!!!!
