This Disc Launcher Gives You Superpowers!!!

i love to take something humans do and then design a robot to help me do it way better and because i'm good at engineering that means technically i'm really good at bowling and setting up dominoes and at arcade games skipping rocks kicking field goals and even hitting golf balls building a robot that makes you really good at something is such a cool feeling that i created crunch labs so as many people as possible could experience this for themselves so for example this is the disc launcher designed right here in the crunch lab so you get this box in the mail then you use your engineering skills to build this from scratch which gives you super powers versus trying to throw this frisbee with just your own lame model boo what kind of super powers well i'm glad you asked oh directed [Music] [Music] so as you can see with crunch slabs the little robot machine you build every month will give you super powers beyond that of a mere human but unlike the movies those super powers don't come from magic because in every case for every build box we're gonna use some natural law in the physical universe to our advantage but unlike my youtube videos where i just show you the cool build but don't talk about much about how it works with crunch slabs we're gonna peek under the hood we're gonna pull back the curtain and unlock the juicy engineering and physics secrets that make it all possible and i should mention that crunch labs is a real place it's where we design all these boxes and it's got a tennis ball cannon and the world's longest hot wheels track and a foam pit and a bunch of other cool inventions and each month when you open your box that comes in the mail you have a chance to find the platinum ticket and if your box has it that means you and your family get to come out and visit me and my team for a day and we'll build some cool stuff together [Music] selfishly i want you to fall in love with engineering and science like i have because it's brought so much delight and wonder into my life and i want other people to experience it too alright so to do this for every discussion for every build box we're going to start with the secret question which is right under this paper it's a tough question but i'm going to spend about 10 minutes using all the random objects on this table and at the end of that 10 minutes you will fully understand the answer even to that difficult question so don't be intimidated if you see the question and you have no idea because i'm going to attempt to wirelessly transfer a juicy nugget of information from my brain permanently into yours straight through that screen you're watching me on right now again it's not magic it's cooler than magic all right so to set up the question i've got a ramp here so i have two cylinders here they weigh the same they're the same diameter the only difference is one is solid and one is hollow now for the question which disc will reach the bottom of the ramp first so in other words if i place them both here and i let them go will the hollow metal one reach the bottom first will the solid wood one reach the bottom first or maybe you think they'll reach the bottom at the same time now this was actually a question i was asked when i went to interview to get my job at nasa so if you know the answer to this you're basically an astronaut now i'm not just gonna release my hand here and give you the answer we're gonna see if we can understand our way to the answer with a couple more demos and so for our first hint i've got two weights here one weighs two pounds one weighs 25 pounds which is easier to move here's the two pounder here's the 25 pounder now all right an object's ability to resist being moved is called inertia basically the more mass it has the heavier it is the more atoms that are packed into this versus this the harder it is for me to move now intuitively you kind of already actually know this because if i handed you two wallets and i said put your pans out like this and i said which one weighs more what do you immediately do well most people will do this kind of do this and kind of do this and kind of do this and kind of do this you're moving it because you know the object that's heavier will resist that movement more so the one that's harder to move is the heavier one it's harder to tell that if they're just both sitting stationary all right well does that help us answer this question well not really because these weigh the same but it actually does provide a clue and i'll show you why right now all right so i've got two sticks here each one with two apples on them they're made from the same stuff one stick two apples so when i move them yeah they both resist the motion the same same inertia same mass but now let me try and rotate them okay so i'm moving that as fast as i can now i'll move this one as fast as i can hold up this is rotating way slower than i can rotate this one well what's going on there huh well actually that does make sense because if you look at the distance this apple is moving on one rotation it's about that far whereas with this apple when i make one rotation it travels this whole distance it has to travel from here all the way over to there and it just takes more energy to move something heavy farther in the same way that lifting this weight from here all the way up there will take more energy than from here right to there aha so what this tells us then when it comes to rotation the location of where the mass is matters the further away your mass is from the center of rotation the harder it's going to be to move it because you just have to move that mass a greater distance all right so let's put ourselves in the shoes of gravity gravity's like all right i got these two cylinders i got to get to the bottom of the ramp this one has its apples evenly distributed from the center to the edge whereas this one has all of its apples around the edge now which one is going to be easier to rotate and therefore get to the bottom first think of your answer in three two one boom photo finish did you get it did you realize that this one would take longer to reach the bottom because it had all its apples at the edge and therefore it'd be slower if so you can now work at nasa and now that you know this you understand why ice skaters slow down when they put their arms out but then speed up when they pull their arms in fat gus and my squirrels even know this because they extend or pull their arms in to rotate quickly to make sure they always land on their feet this knowledge can also help you with things like the pinewood derby car race i did a video on this a few years back but there's two things you can do with this information that will make your car definitely faster as long as it's legal the first is to take the normal wheels and dremel off the flat part so that it turns into a disc like this why does that help well let's check out what we refer to in engineering as a cross-section drawing so basically what you're seeing here is if i slice the car this way and looked end on you would see the nail come out from the side and this is the wheel cut in half so the original wheel has this edge here right whereas this one is just a disc this wheel has a couple extra apples here on the edge that you just don't need and that means the wheel will start rotating faster and it'll take less energy to get the car moving and the other thing you can do is just take off one of the wheels altogether the car is stable on just three wheels and by removing one wheel that just means that's one less rotaty thing that's gonna take some of your energy that would otherwise let it quickly move down the ramp isn't that cool that once you learn a principle it can be applied in a bunch of different ways that's why learning a principle is always way better than just memorizing a bunch of facts okay now i've got to come clean here because there's a bit of a catch there's some fine print on the difference between these two and it's a principle we're taking advantage of for the disc launcher we already know that the solid one is gonna reach the bottom of the ramp first but once we get to the bottom which one is going to roll farther along the floor well let's test it out interesting so it takes longer to get to the bottom of the ramp but then it rolls farther so if you place all your apples at the edge instead of the middle it sort of becomes a mechanical battery where you store this energy up but then slowly release it over time and there's situations where we can use that to our advantage in engineering we call that a flywheel where do you see these in real life well here's some examples for something like this toy car this blue part here is your flywheel and as i wind it up it starts storing that mechanical energy like apples on a stick or you can see this hot wheels launcher has two of them [Applause] baseball pitching machines use flywheels a lot of engines actually have flywheels on them here's a homemade version of an engine made by my buddy bruce and you can see the flywheels give it momentum to keep it running smoothly if you remove the flywheels then it keeps getting stuck at this over center point because there's nothing to take it through to the next piston stroke and if you look closely at my playing card machine gun you'll also notice a flywheel right here which finally brings us to the disc launcher this is a flywheel that means when we turn it on it sort of takes a while for it to get going just like the disc coming down the ramp but it's storing up all that mechanical energy from the motor so now we put a disc in there it can easily transfer some of that energy to the frisbee and fling it really far compare that to this version that has no flywheel you can see i can easily stop that with my fingers there's just not a lot of stored up energy here in fact if i turn them both off this one first it takes a while for this one to even slow down and dissipate that energy whereas this one almost immediately turns off this is the silver disc that goes slower but rolls across the floor really far it stores up that mechanical energy and is able to transfer it to our discs so your gear badge this month is a flywheel each month you'll collect a different gear badge with a different engineering principle on it and then at the end of 12 months at the end of the year it'll make a really cool gear train like this at which point you'll unlock my signature which makes the whole thing official okay so ordinarily you know you earned your gear badge we talked about the new engineering principle we'd be done with the science part but gosh dang it with frisbees there's just some really juicy physics going on that is just fascinating as to how they fly that i gotta throw this in as a bonus for example why does this fly so well but then if i take a similar shape that's just flat and it doesn't well there's actually two things the first is that it flies a little bit at an angle we call that an angle of attack as it moves forward it basically bumps into all these stationary air molecules and it causes it to deflect up if you've ever put your arm out the window of a car you know this feeling angle your hand up and you can really feel it pushing back on you but there's also a second effect you notice how the edges are always curved like this that's because as the air passes over the frisbee grabs it and pushes it down it's sort of like if you put a curved spoon in a stream of water that curvature changes the direction of the stream to head more that way but maybe you're like yeah but that's watermark and air is different well i've got a poor man's wind tunnel here where i've taped some white threads to the front of his frisbee now i'm going to take this air and i'm going to blow it straight directly down if it doesn't have what's called the cowanda effect where it curves it around these will just keep going straight down with the air but watch what happens they curve around just like the water and here's why that matters the frisbee is basically curving air down all around it this is like it's wearing a jet pack because if you wear a jet pack newton's third law you push a bunch of air down that reacts and pushes you up in the air well that's what a frisbee is doing it's jet packing itself to stay afloat using the kwanda effect and that's just cool so there you go if you learn something new tell your siblings or your friends tell your parents not only is it fun to share something new you learned but it helps you remember it better too all right so next i'm going to go through a speed run of how to put this thing together and the intent is that you just kind of watch it to get a sense of all the steps and then later on when you put it together you can just use the booklet or you can re-watch this video and pause especially if there's any steps that are giving you trouble i'll run through this in like three minutes flat but if you're doing it at home for the first time it should take you anywhere from 20 minutes to an hour to put it together first we need to find the dc motor and our circular adhesive foam next peel it off the paper backing and stick it down over the dc motor shaft peel the second paper backing off the foam then locate the wood launcher piece and slide the motor shaft through the center hole in the back of the launcher now it's important you make sure the motor shaft is centered in the hole and that no blue foam is visible from the front of the launcher otherwise your flywheel just won't be properly aligned find your flywheel and stretch your largest rubber band over the flywheel so it sits flat in the outer groove then slide your flywheel onto the motor shaft which should be sticking out of the front of your launcher make sure to press the flywheel and the dc motor together just a pro tip the harder you press those together the stronger the fit will be in engineering when you smush a shaft into a hole like that we call it a press fit then flip your launcher over and slide the red motor tube over the motor body the two will be held in place by the adhesive foam next grab your battery pack and pull out the clear plastic tab so now electrons can flow through those wires once we turn it on then grab the rectangular adhesive foam and peel it off the paper backing and stick it to the side of the battery pack that has the on and off switch and peel off the other paper backing then stick the battery pack to the back of the launcher so the on off switch is visible through the rectangular opening from the front then flip the launcher back over and connect the wires of the battery pack to the wires on the dc motor make sure you connect the red wire to the red wire and the black wire to the black wire and find the yellow foam guard rail and peel and stick it to the matching shape on the launcher then turn your switch to the on position and make sure your flywheel is spinning in the same direction the arrow on the wood is pointing another pro tip you can actually switch the direction of a dc motor just by switching the wire connection so if your motor is accidentally spinning backwards it probably means that you have your wire connection swapped remember red goes with red black goes with black now for a quick test as an engineer you like to test as you go along so grab a couple of your red discs and turn the launcher on then place one of your discs onto the dotted circle then push it towards the flywheel until it gets pinched in between the rubber band and the guardrail and let it rip now find the small yellow wood piece then peel and stick it to the matching shape on the wood launcher grab a bolt and the dark blue trigger bar then slide the bolt through the largest hole in the trigger bar and the matching hole in the wood launcher then from the back screw a nut onto the bolt until you have a small gap in between the nut and the back of the wood launcher that gap is important because it allows the trigger bar to move under the force of your finger and here's another pro tip for building if you have two nuts you can actually make them a locking nut so you take the extra one that we included in the kit and you just twist it into the back of the other nut and now they're both locked into place and yet the trigger bar can still rotate freely next grab the smallest of the three rubber bands and loop it through the smallest hole in the trigger bar it should pop out the back of the wood launcher then loop both sides of the rubber band around the notch on the right side of the wood launcher next slide the two wooden rectangular pieces into the parallel slits into the wood launcher then for the back of the launcher hook two white o-rings over the tips of the wooden rectangular pieces this is what holds them nice and snuggly in place then find the dark blue disc tube and slide it in between the two rectangular pieces make sure the tube sits in the two cutouts in the wood pieces that way there's a gap underneath the tube then stretch the medium sized rubber band around the dark blue disc tube making sure the rubber band sits in the notches of the two wood pieces then grab one of the plastic tabs and slide it in between the rubber band and the tube it should sit in the same notches that the rubber band is sitting on the tab should also be on the same side of the tube as the on off switch then grab a couple of your red discs and drop them into the disc tube making sure the frisbees aren't upside down so now that it's fully assembled you can see that as you push on the blue trigger bar it in turn pushes only one disc out the bottom of the disc tube at which point the rubber band on the flywheel grabs the disc and pinches it into the foam guard rail that causes the disc to spin and shoot forward out of the launcher then what's cool is that when you release the trigger bar the next disc automatically drops down into the perfect position to be pushed out for your follow-up shot out of the launcher all right so with each build there's what i like to call the engineering hustle and this is your opportunity to do what i do in my videos where i challenge say my nieces and nephews to a rock skipping competition and then of course i unveil the robot that i filled and domination ensues or maybe i challenge the world's greatest field goal kicker to a showdown and then of course i bust out my robot but the key is you don't actually reveal the robot until they've accepted a challenge so in this case what you could do is challenge your sibling or maybe a parent to see who can more accurately launch a mini frisbee maybe i don't know put some dessert on the line so you let them go first and fail miserably and then of course when it's your turn you bust out your little robot machine and dominate the competition okay and so finally i want to explain what i call the prototype 2.0 the idea with crunch labs is you get this and you put it together and it's super fun for a day or two but now you have 28 more days till the next box comes to take what you've learned here and step it up to the next level in other words this is just the first prototype engineering is a very iterative process the biggest mistake i see even experienced engineers make is they try to design the whole thing in one step but it actually takes a lot of steps you can see here all the different versions we had to go through before we finally realized this is the best way to make a disk launcher my absolute favorite kind of feedback is along the lines of this tweet i got from a mom my eight-year-old watches one mark rover video and suddenly he has all these ideas he wants a weather robot for the house he wants to make an automatic fish feeder and he's determined to make his own squirrel obstacle course so the question is what can you do to take this design and make it even way cooler maybe it's a moving target that you've gotta hit maybe it's a new type of game like homemade frisbee cornhole or perhaps a fun contraption that will capture a disk and then share and send me a link to your best prototype 2.0s on socials and we might even feature some of them alright so that's it you've earned this month's gear badge and now you can go off and put your robot machine together to give yourself some superhuman powers and i'll catch you next month right here crunchlabs oh and if you're watching this and you haven't yet ordered your buildbox subscription from crunchlabs then what the heck are you waiting for visit crunchlabs.com with the parent and once you're there you can learn more about how it all works thanks for watching

Channel: CrunchLabs

Views: 862,927

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Id: Nw6ry2apRAQ

Length: 21min 10sec (1270 seconds)

Published: Wed Jun 15 2022