I Built a Working Lego Clock

This is the inside of a clock. It's not that complicated. So what if I tried making one out of LEGO? Well today I'm going to build a completely functional LEGO clock with an hour, minute, and second hand. And it has to tell the time accurately. This is definitely going to be Okay so to make sure everything on our clock hard to do but it'll be worth it. is accurate we need to use gears. And LEGO has two different types of gears. There's these thicker beveled ones and there's these thinner regular ones. Let's do this. So with that these are all of the gears that LEGO makes. And I'll pop up how many teeth each one has. And this 40 tooth gear I got a whole bunch of just for this video that I probably won't even need that many of. Okay so to run the entire clock we need a motor. But this is a LEGO Power Functions motor so all All we can change the speed with is a battery box and on the battery box we only get seven Seven different speeds for the motor. And for a clock, we want the motor to be spinning at exactly 60 RPM. Or in simple terms, it just spins 60 times every minute. I'm not sure why I said 60 RPMs here, I meant 1 RPM, because the second hand of a clock moves one time per minute. Eventually I fixed this, but for now, every time I say 60 RPM, I meant 1 RPM. So this is the second hand of the clock, and then we gear everything else from there. But since we can't set this to exactly 60 RPMs, we'll use LEGO Mindstorms instead, which can be coded and put exactly at the 60 RPMs we need. Now that we got that, we gotta figure out the gear ratios for the minute and hour hands. Okay, so I got a 40 tooth gear and an 8 tooth gear, and if I put those right next to each other and spin the 8 tooth, I have to spin the 8 tooth gear 6 times to get the big gear to rotate once, and vice versa if you spin the big gear. And since we need to slow down our motor for the minute and hour hand, we're gonna attach that to a smaller gear, and then every time it gets spun, it slows it down by a lot. Now since the motor is spinning 60 times a second, we'll have to gear that down by 60 For the minute hand and then a And another 60 for the hour hand. So instead of a gear ratio of 1 to 6 like this, we need a gear ratio of 1 to 60. Which is a lot harder. Now I actually found this chart online by Serial and it is perfect. Each side has every single type of LEGO gear and then it gives you every single combination possible and all of their ratios. And so after looking at that I think I know what to do. So for the start of it we can put a 40 tooth and an 8 tooth again. And then on that same axle as the 8 tooth I can put a 36 tooth. And then a 12 tooth to connect to that. So I'm just going to put a beam across all these just to hold them together. And then on top of this last one, I'll put a 16 tooth. Now I need to put an 8 tooth next to this 16 tooth. And if you notice, when they go together, there isn't an axle hole for them to connect to. So it needs to go two and a half bricks apart. So these are the main Lego Technic bricks. And you can see that the axle hole is in the center of the two studs. But they also make ones that have Technic holes lined up with the studs. So what we can do in this situation is add one of those thinner ones right there. And then put an 8-tooth next to it. And it works. Perfectly then on top of this last 8 tooth we can put one more 16 tooth and then we can add our final gear an 8 Tooth gear. So now with all the ratios multiplied We got 5 times 3 times 2 times 2 which all added up equals 60 So if I spin this one on the end 60 times and this one should spin once So yeah, as I was saying, it's kind of complicated Okay, so I ordered some new Lego Mindstorms for this video and this is the box and it has some issues So I already have some pieces right here and that's because these pieces came out of this box Like literally just carrying this box a little ways all these pieces came out So it makes me wonder how many pieces came out during shipping But the good part is that this isn't a set or anything so I don't really need the pieces that fell out I just need the bigger Lego Mindstorms pieces. You can just hear how loose the pieces are. Yep cutting in here There's already a piece that's almost made its way out So I actually open this upside down like this is hard to show but there's a bunch of pieces down in that corner Oh, yeah, well, it definitely popped open. So we're gonna oh and get this out of here All right. So yeah, there's this many loose pieces in the box, which means I'm guessing pieces like this fell out of the box a ton. It's not that big of an issue because I already have a buttload of a lot of these pieces, so it doesn't matter. So we got this and let's lift this upside down. Shoot. Pieces falling everywhere. Okay, so I probably shouldn't have opened this upside down now I think about it. And this is the most important part. The screen, I want it to be in really good condition. This one's fine. It's got a couple scratches, but there's a little chip at the bottom of the screen, which is kind of annoying, but it should work. Yeah, this should be all electric parts. Oh. Yeah we are making a mess. All right so now it's right set up this is the lid to it and then this is on top of that and then there's a tray that holds all of the loose pieces which once the lid comes off these are at the top of the bin so this is why these spilled everywhere. It's turning on. The good part about this is my NXT that I've been using for forever the screen doesn't even work on it so having a working screen is kind of weird. So it'll definitely be nice. Okay, so now that we have these motors, we can use one and attach it to the clock and get this thing actually working. Okay, so I coded the EV3 with some Python. So this does one full rotation in a minute and then I just have it turn off from there, but I can just keep it going for the clock. So we click this and then I got a stopwatch over here. When it starts, there we go, it's a little off. And literally right on a minute, it stops and completes its circle. It seems like the bigger motors can handle those slower speeds better. You can see if I start this. So that movement right there compared to the other smaller motor, it's a lot less jagged. So I'll probably end up using one of these bigger motors on it just for that. But these work really well for it. Okay, so a clock has three hands and all three of those hands come from the same point. But making three different axles go through the same point out of LEGO is kind of hard to do. If you just use a normal gear, it's just one axle that can power it. But luckily, LEGO makes this gear where an axle can go through and this top can actually rotate too. So that's two points spinning. But the issue for a clock is we need three. Now LEGO does make a big version of this gear. I have it right here, but you can see this gear isn't gonna fit in that. So the only other option I found was getting these banana gears. Okay, so I can put these in a circle so it makes one massive gear. We have this set up that's one of those gears that's hollow inside with a axle hole at the bottom. So then we have these spinning separate from each other. So that will go in the center and then we can have some sort of gear spinning this very outside gear. So then that'll be three axles running at the same time all centered around the same spot. So right now I'm going to work on getting all of these gears set up so that they have an axle that we can then use gear ratios on to slow down to be a clock. Okay, so I got the main outer circle with the worm gears done, and this is a lot harder than I thought it would be. I needed it so it wasn't hinged from the center because we're already having two points in the center. So I actually saw this other person's video, and what they did to solve this problem is they used these gears put upside down. I changed up a couple things, but that's like the main bit of it, so then it can actually rotate without anything in the middle. And yeah, this was really hard to get right, but now that I have it right, we can put the other two in the middle and then get all the axles out the way that we wanted. Okay well now all the hands work so if I spin this axle down here it'll spin the outer layer which we can just add a hand to it'll be really easy and then if I spin this side one right here it spins the minute hand and then if I spin this very center one that just goes straight through to the second hand. So I have all three of those axles and they're all spinning around the same point which might not seem complicated but that was a lot of work to do. I actually had to change on the bottom of this big circle to a bigger version of one of these gears because this whole This whole circle has 140 teeth. And if we gear it with a 12 tooth gear, that gives an uneven ratio. See, the only Lego gear that I could use was the 20 tooth gear because 140 divided by 20 is seven. OK, so I actually reworked the mechanism that spins this minute hand. So this main gear, which is one of these that have the two different sides, it's a really weird size of gear. It's 28 tooth and no Lego gear perfectly goes into that. Make a ratio that isn't a fraction. So what I had to do is get an eight tooth gear and have that run it. And then that is a 3.5 ratio. And then out back here, I have another ratio. That's a 1.5 ratio. So that evens out to be five and gets rid of that annoying 0.5. Okay, well, I realized that my math for this section for gear ratios was off. I had a eight tooth gear spinning a 12 tooth, which is a 1.5 ratio, yeah. But I was adding these together and gear ratios get multiplied together. So those multiplied would add a 0.25, which we don't wanna mess with. And so after going through all the options, it looks like the closest we can possibly, get with lego gears is a 58.325 ratio and not 60. So the minute hand is going to be the slightest bit off from the others just because lego gears are limited and I can't choose the right gears to make the right ratios. There still is friction with all the gears and stuff so the other hands might be off anyways so maybe it'll end up lining up. Well I don't know we'll see. This is really confusing with gear ratios but it should be cool in the end. Alright, well I made some really good progress, you can see. There's this knob right here and if I spin it, then both the second and minute hand spin. You can see how many gears I had to use for that, and I even used a chain because then I didn't have to worry about lining up gears right here that were the same. And it actually works really well, I'm really surprised at how well it works. But with all these gear ratios added up, I changed a couple things because some of the gears wouldn't work. It's 58.4 1.55 so we're 1.55 under that 60 that we're looking for but like I said earlier this gear right here is making it so that is not possible whatsoever and we have to use that gear because it has a hole in it. Yeah to see how well this works I'm gonna line it up right at the top and then I coded a thing in my mindstorms to spin 60 times at full speed just so we can test if this works or not and so let's run it. So you can see it's the slightest bit off it actually went past 60 for some reason that's probably the looseness in the gears you can see I can just wobble this back and forth but it's pretty accurate it was straight up before and after 60 rotations of the second hand it's gone basically to the middle. So it's nice that we finally have the minute hand done but now we have to work on this outer edge for the hour hand. So to do that one we need two of these ratios it's a 60 gear ratio and that is the speed that the hour hand will go compared to the second hand. Now technically if I wanted to make this project a lot simpler I could just use three motors and have them all spin at different RPMs but at that point it's not even a clock. Using all the gears and stuff is how clocks work and it's kind of cool to see. So yeah let's get this hour hand working. Okay, well I finally got the hour hands done and that was a lot more complicated than I thought. My original gear ratios were all screwed up and so I had to revise it a bunch of times. But now as you can see, there's so many gears down at the bottom here to gear it down. But in the end, the ratio for the hour hand is 3,563, which is super close to 3,600. So it's going to be really accurate. This is the hour hand right here. And if I just keep spinning, you probably can't tell, but the hour hand is moving. That's why I got a motor here. So let's just attach this motor real quick. So if we run this, you can see it's kind of loud, I don't know how loud it is for you, but everything's moving in the right direction, the second hand, of course at wrong speeds because I'm just trying to get, just trying to show it, but the hour hand is barely moving. But it's moving, the hour hand just takes forever because the motor back here has to spin 3600 times for it to move, one full rotation. Now I actually ended up using more chains back here to drive the hour hand, it just makes it way easier than trying to fit gears that won't go together. See how we're so close to having this clock done, the last thing I need is a mount for the motor so it can actually stay in place, and then we should be able to get this thing up and running and see how accurate it really is. There we go. Okay, so I added some code to the Python for the EV3 brick and now if I run it, it'll turn the second hand at 1 RPM, which we want. You can see it moving there. And then I added a stopwatch so we can prop this up and have the actual time right here. And then our Lego clock running over here and we can see how accurate it actually is. So I'm going to run this in real time for as long as this can go with this battery plugged in. So I'm not sure if this will die or what, but we're going to see how long this thing lasts for. Well I've had this thing running for six and a half hours now which is just insane. I did not think it was going to last that long. Even though it's plugged in I was thinking it might use more power than it's getting so it might die through that but it hasn't yet and I thought maybe Mindstorms has like a turn off limit so it'll just turn itself off after a certain amount of time but six and a half hours and this thing is still going. You can see that second hand is still chugging along. But as you notice this says six and a half hours, but the hour hand looks like it's at like two hours And that's where I realized something is wrong. For the right time this hour hand should be about like down here I think where I screwed up my math is the second hand and the minute hand are in segments of 60 But what I didn't think about is the hour hand is in segments of 12 not 60 So I think that's what screwed up with it, and I need to fix it. But other than that this thing is working amazingly Amazingly. Okay, well I'm going to fix the hour hour hand on this clock real quick instead of the ratio for the hour hand being 1 to 3600 which I originally thought it would be it's only 1 to 720 which is way easier to make with gears. I'm only gonna have to use four pairs of gears instead of like the like 10 that I used for the 3600 ratio so this should be pretty easy except for the fact that I have to take apart the old one. Okay, well, I got the hour hand gear ratio reworked. It kind of looks the same down here, but I actually shrunk it down. It used to come out to like right here at the bottom. It's way smaller. It's way less complicated. And with my quick testing, I'm pretty sure this will work now. And the hour hand goes in segments of 12. So now let's run it for a couple hours like we did with the last one and see if it actually stays accurate. Okay, the clock has literally been running for 12 hours. And yes, it is still working. So I think if I wanted to, I could just leave this on constantly as a Lego clock, but I think that would be horrible for the motor. So after 12 hours, I'm finally going to let this thing stop running. Hopefully I didn't break anything. There we go, surprisingly the brick isn't hot or anything. It's just normal temperature, but i'm glad to see the lego clock actually works And it's surprisingly pretty accurate. Okay feature me here I'm, not sure what happened to the original clip of me talking about these hands. So right here It's almost 12:04, so the hour hand should technically be a little closer like up here But honestly, it's really close as it after 12 hours, being that accurate the minute hand however is where it kind of changes the minute hand should be at four which is about like right here but as you can see it's down here at like 25. So that one definitely got screwed up because of that dumb gear right here and the second hand just stays accurate because that's driven directly by the motor. So yeah it was pretty accurate. Well there's the working lego clock at least mostly working because it's as close as we can get with lego. This video took me over a month to film because of how complicated this clock is. There were so many times that I screwed up with my calculations and I had to redo the entire gear ratio which sucks but I did learn a lot with these gear ratios and I also learned how to to get Python on EV3. So let me know down in the comments what you guys want me to make with the EV3. But yeah, if you wanna check out another video similar to this, I'll have a link up here in the corner and down in the description. But as always, make sure to like, subscribe, and hit the notifications bell. I am in picture mode. So I can put these in a circle so then it makes one like massive. Dude, it is still massive. This gear ratio, which this, oh. Bro, I have the dishes curse, I swear, as soon as I film, no matter what time, dishes.