 Hi, welcome to the MIX, the Teen Center at the San Francisco Public Library. My name is Ileana and I am your humble host for our STEM Challenge Yourself series, where our amazing librarians come up with science experiments that you can try at home. In today's challenge, you are going to meet the predecessor to the robot and be able to make your own. I will let the Challenge Master walk you through the science and the steps. I think you're ready. Hello everyone. My name is Librarian Anita and today I am going to answer the question, can you make a machine out of a cardboard box? Well I am going to show you how. The instructions for this came from the Exploratorium's Tinkering Studio. They have wonderful instructions on how to make cardboard automata and automaton is a precursor to the robot. It's a machine that can move on its own and I took the Exploratorium's instructions and adapted them to use my favorite fastener, duct tape. For this project you will need a small cardboard box, two bamboo skewers, about 12 inches long, a sharpened pencil, a straw that can cut with scissors, the first step you're going to take the cardboard box and open it up and flatten it out and then you're going to take your scissors and cut off the flats. Now it takes a while to do this so if you are following along at home please feel free to pause the video when you need time to work and come back to it. I have examples I've already made so I'm going to show you. Here is the box with the flaps cut off. You want to have these two open sides like this however you may notice it has a hard time staying up on its own. So we're going to need to make some supports for this lovely box and you're going to take one of your cardboard flaps and just cut four triangles with a nice right angle on each of them and these are going to become the supports for your floppy cardboard box. You're going to take four of them and take one and tape it into each corner. Now what I like to do is take duct tape with little strips out of it. You only need a couple of inches so you take your duct tape, take the support and tape it in. And once you get all four of them you'll have which is the sturdy support that you are going to work with to make your machine. Next you're going to take one of your cardboard skewers. Take one of the sides and find a spot right in the middle and take the pokey part of the skewer and poke it through. Go all the way through to the other side, poke it through the other side, beautiful. Next we're going to, this is going to be the axle machine which is going to spin and we need some more pieces for our machine which I'm going to explain to you. You're going to need to cut pieces out of your cardboard flaps, the extra cardboard flaps that you have lying around and I used circles to start, a cam and a cam follower and it's, the cam follower is about three inches wide, the cam is about two and a half inches wide, it's a little smaller, it's nice to have the cam follower a little bit bigger and I used jar lids from my cabinet, I just found one that was about the right size and one was a little bit smaller and I laid them down on a piece of cardboard, I traced them out and that's these. You were also going to need some little scraps to hold the skewers, these are called bushings and you can use any little scrap of cardboard that you have over all this. Take the skewer out, you take a little piece of cardboard, you put your skewer through it, it's going to be nice and snug in there and then set it aside. The next thing you're going to need is a handle, so just cut a little rectangle out of your flap. So now we're going to take one of our skewers, look it through the center of our cam and then we're going to put the skewer back through the holes that we've already made in the side of the box and we're going to want to adjust it so that there's about one inch on one side. I like to make this a little bit longer, I'm going to attach the handle here and you want the cam to be right there in the center. Of course this cam spins around on its own right now which we don't want so you're going to need to secure it with duct tape and here's an example that I've already made. These little strips of duct tape, I wrap it around the skewer, flatten it down onto the card and then that holds it in place but you don't want to do that until you've got it like really placed exactly where you want it so then at this point I know this is in the center, I've got my inch on this side and my pokey side I've got maybe two and a half or three inches and I'm going to carefully slide this out and tape it like this and then once it's taped you can put it back in as the time where you get your bushings out and you place one on one side, one on the other, looking good and these help keep the skewer from moving around too much so you don't want to slide all over the place and then you take a piece of duct tape and the pokey side I like to cover up the pokey side make it into the handle you just tape, tape your handle, there you've got your cam and your ax and that's this next example right here actually alright next thing you're going to want to do is take your sharp end pencil and directly over your cam you're going to want to a hole and slide the straw in okay now we've got a lot poking up out of the top here I'm probably going to cut it down a little bit and I'm also going to want to secure it a little bit with some duct tape around the top and this is an example I've already made this is duct tape secured the straw and now we have the next part our cam follower the cam follower is going to lay on top of the cam and the motion from the cam is going to transfer it to the cam follower and to the top of our machine so you take your second skewer and lay it and take a strip of duct tape and just like I did before tape it down with different pieces it'll look something like this and then once you have this ready you're going to carefully slide it through your straw and up and up and lay it so that it's on top of your cam and now it looks like the pieces are fitting together and doing something this is where you get creative and use some paint and some of your extra cardboard from your flaps to make something to put on top of your skewer on the top of your machine because this is corrugated cardboard and has little holes in it I can just slide this on and it's all ready to go and here you go you've created your machine what is going on here the science behind this involves friction is what happens when two objects rub against each other and in this instance we have the handle is moving the axle of the machine the axle is moving the cam and the friction between the cam and the cam floor is transferring the motion from the axle to the cam to the cam follower finally or a little whirligig on top this is pretty cool so that's what it looks like when you're using a circular cam that's what the motion looks like goes round and round does it look like if you use other kinds of cans I have a machine here that has a triangular cam that looks like this in the center of it and this cam it does rotate a little bit but it's to go up and down more and then I have another machine which has an egg-shaped cam in the center and the hole is a little bit off center and how does this one like to move it goes up and down and around at the same time so you can play around with different kinds of cams switch them out to make different options in your machine you can also play around with different toppers to put on top of your machine so think about what might go up and down it goes up and down to go on top something that goes round and round to go on the one of the round ones there's lots of rooms to experiment thank you so much for joining me today back to you Ileana Wow Anita that was fantastic I love that with some patience some cardboard and some tools you can make a cardboard machine yourself I'm shout out to the Exploratorium who inspired this project and who bring science to kids every day for more tips and tricks and resource lists on this STEM challenge and other STEM challenges be sure to check out sfpl.org slash STEM challenge keep experimenting keep observing and stay stem-tastic