In this chapter of the Zero to Maker workshop, we're covering CAD modeling, an incredibly powerful skill that will allow you to go from idea to real manufactured part. If you're new to this workshop, Liam and myself will be taking you on a fast-paced and practical journey to learn a wide variety of maker skills so that you have the tools and knowledge to make anything, so follow along as we develop our own projects and share the insights into the process.

So far we've chosen a project, I'm making the chassis of an autonomous robot, and we've kind of gone ahead and sketched out a rough design of it all. This week, as a part of the Fab Academy course, we were tasked with diving into some different digital design tools to go ahead and create a virtual design concept of our project. And there are a lot of ways we could do this, we could sketch it digitally in something like Inkscape or Illustrator, we could use 3D modeling software like Blender, but we are going to skip right to the end goal here and 3D model our project in a CAD program.

CAD or Computer Aided Design is just a type of software that allows us to 3D model something precisely and accurately. Every stroke on this metaphorical canvas is exact and mathematically defined. And this type of modeling is great for making technical parts, making things like engines, glasses, bikes, robot arms, door hinges. And CAD modeling is a vitally important maker skill because it lets us take an idea or concept of something from our head, create a 3D model of it, and then we can take that model and get it 3D printed or make it with a laser cutter or CNC machine. It's just very easy to take that model and get it manufactured in the real world.

So this week, we're just going to dive into some CAD modeling basics and show you how I went from robot concept in my head to a digital model that is nearly ready to start 3D printing. There are a wealth of CAD programs out there. You might have heard of FreeCAD, AutoCAD or Fusion360, but we will be using Onshape. Now, they all kind of behave pretty much the same. So if you learn how to use one, you're actually learning how to use them all. But Onshape is going to be our go-to because it's free and you can use it in your browser, which is fantastic. You will need to create an account to use it, though. And if you're a student, it is definitely worth setting up a student account. You get a whole bunch of little extra bells and whistles to use.

All right, I've created my account and I've just opened Onshape for the first time. You're probably not going to have all your projects here, but let's create a new one at the top here. Sweet. We're just going to call this Leo Test 2 and it should open. And we're now greeted with our modeling studio. At the top here, we have all the different tools that we can use. On the side here, we have the parts history tree, and then we've got these planes in the middle where we're actually going to start modeling things off of. First things first, camera controls. If you simply right click, you can rotate around your part. And if your middle mouse click, you can drag your part and pan around it. And at the top right, we also have some more view controls. If we click on this, for example, it puts us nice and square on with whatever we're looking at. And we can rotate this way a bit. We could look at it from this angle. We could look at it from the top angle, and this is going to come very handy in a future step.

So there's really only three major steps to modeling something. And we're going to go over just a quick demo now, and then we're going to go and actually build part of the robot and then build it all up. The first thing we're going to do is we're going to create a sketch and we're just going to go up to the sketch button. And now we're going to select a plane or something to sketch off of. And that's where we're going to select one of these planes here. This is not your part. It won't show up as a part of your model. It's just something that we can draw and build things off of. Now, whenever you start sketching, it's usually a good idea to use this top camera control here to bring yourself nice and square on with what you're drawing, because drawing at an angle is often very tricky.

Now we have a whole bunch of different drawing tools up here for lines, squares, circles, arcs, different polygons, stuff like that. But for now, we're just going to draw a really simple square so we can do so with that. And as you can see, we have these little boxes pop up, and that's how we're actually going to define the dimensions of our shape. So when that pops up, we can just punch in the number we want, or we can go and dimension it later with the dimension tool up here. So we can just click on that, click on the line we want to specify, and I can just say I want that to be 80 millimetres. Sweet. We've made our sketch, and now the next step is to extrude it. So I'm just going to tick that. Yeah, we're done with the sketch. And now I can select the shape that we've just made and go up here and extrude it. And this is going to turn it into a 3D object. And a lot of these tools will have this little box up here that pops up, and this is where you can change the direction, how deep you want it, and how big you want it to extrude out. There's a whole bunch of tools here that you can use. But for now, we're just going to specify we want it to be 50 mils. This is just arbitrary for a learning demo.

Now we've got a 3D shape. We can modify it if we want. And there is a whole bunch of tools up here that we can use. A very common one that you'll be using is the chamfer and the round one, or the fillet here. We can click chamfer, and then it comes up and it says we need to select what we want to chamfer off. I'm just going to select this edge. And as you can see, we get this nice little 45-degree cut into it. And you can change how much you want it to cut into it. And it's a very similar process to make a round on the end, just like so. You can also just drag it there if it pops up. And those are the three basic steps. And we can keep repeating them over and over in any order to build what we want. So for example, I could now choose this surface and produce a sketch on here. I might make a circle on there. Cool. And then I might extrude it, or I could cut into the object and remove something from the object like so.

Now on the left-hand side here, we've got a history of everything that we've done. And you can actually go back and delete or change whatever you want on the fly. For example, I could go back to sketch two and I could grab the dimension tool and make that circle 40 millimetres bigger. Let's make it a bit bigger. And if I click yes, it's going to then go through all the steps that are after it and remake the model with the change that we've done. And that was basically it. 90% of the time, you're going to use the tools that I just showed you in the last few minutes. But let's go ahead and get some practice in and model part of a project.

So this is my model so far, and we're going to be modeling another one of these arms here that act as a part of the suspension of the chassis. So if I'm looking at this part, I see a nice kind of little sketch there of this ladder shape that we could make and then bring up and then we can do all the little features on it afterwards. And I'm just going to start by creating a sketch on this plane here. Remember to align it so we can get a nice square on view to accurately draw things. So I think I'm just going to sketch this all with the line tool. So I'm just going to click on it and make an initial sketch to start off. And as you can see, it's kind of wanting to snap nice and horizontal like that. This is called a constraint. So I'm just going to click that and I'm going to make it 200 mils long. And now I'm going to manually assign a constraint to it. All of these tools up here are constraints and they do different things from saying that two lines must be equal to each other, that these two lines must be tangential, parallel, they might have to be nice 90-degree angles. And constraints are kind of just the rules we give to all of our lines to give it a nice and solid and well-defined shape.

So just for this example, I'm going to choose the midpoint and I'm going to say that I want this point here to be the middle of this line and see how our line snapped into position like that. And it also turned black. If I go back here, you can see that it's blue and now it's black. When it turns black, that means it is fully constrained and it's nice and locked into that space like you can't change it because it is fully defined where it is.

So I'm just going to grab the line tool and start sketching the rest of our arm. And as you can see, it actually likes to snap with these constraints and Onshape and most CAD softwares are really smart. They kind of figure out what constraint you're actually wanting to use. So we're definitely going to be using that because I want all of this to be at nice 90-degree angles. And I'm going to come in and I'm not really worrying about dimensions here because we can come back and dimension it later. Pop it there and look at that. That is another constraint because this one is saying that this line here should be as long as that line. We're definitely wanting to do that. So I'm going to bring that down and if we hover over this one, I can say that this one is as long as that. I'm just going for nice and square drawing here. So I'm just going to say that that one is also in line with that up there and I'm going to hover over that one and that's Onshape is going to know that I'm wanting to put it in line with that and same deal there. Sweet. Awesome. Now we have kind of a rough shape and we can go through and start dimensioning it all. So I'll just dimension this bottom one here to be 200 as well. And then I'm going to dimension this one to be 40 and this one to be 40 as well. I'm getting these numbers just from my sketch that I made earlier. This one should be 20 and this one should also be 20. Now see what happens when I set this side to 20. It's because when I assign those constraints, I actually said that this line should be as long as this line. And if I adjust one of them, the other one should change automatically to adjust. And this one is 80 millimetres. Sweet. And see how that one also changed. Awesome. And that is our shape nice and modelled up. Now, if I dimension this one to be, say, 30 millimetres, I have done something called over-constrained the model because I said this line is 40 and this line is 30 and they're meant to be the same size. So Onshape goes, what are you doing? And it makes it red, which means we've over-constrained it. And this is a very common thing for beginners to accidentally do. It's kind of one of the learning curves in CAD. So if you ever run into this, you've over-defined your sketch and you'll need to go back and figure out what you've done.

So now I want to put a box right smack bang in the middle here so I can select the rectangular tool. And if I hover over this line here, you can see that the middle point pops up. And if I drag across, you can see that the dotted line now lets me put it in the middle. And this top one here also does that so I can hover over and then make the box there. And as you can see, it also wants to line up to there. But we're just going to click there from now. And this is just another example of Onshape being really helpful with its constraints. Now, I could dimension this side to be 80 mils like so. Or another way I could do that is I could go back, control Z that back, and I can use the equals to set this line to the same size as this line. And this means that now if I change that one, they both change as well. And I'm just going to set this top line to 75 mil, which was on my sketch. And that is our sketch done. So I'm going to hit finish. And now we can see we've just created that 2D shape there. I can then go ahead and select it and then come up to extrude. And then we're going to extrude it to a depth of 20 millimetres like so. Sweet. And now we have something that's starting to resemble our part. I think the next thing we'll do is make this hole on the side. And it's actually on both sides like so. So we'll come to here and then we're going to actually put a sketch on the side of our part like so. Click it and then hit sketch. Make it nice and front on.

Now to do this, I'm going to be using a construction line, which is a really handy tool. We can first select it and then we can draw a normal box or line or shape or whatever we want. And see how these lines are dotted? They're not actually part of the shape that we can use to extrude up. They're kind of just like a reference line that we can use. So I'm going to go here and choose not the centre point rectangle, just this rectangle. And then I'm going to hit construction. I'm going to select the top left here and then I'm going to bring it down like so. I'm then going to dimension our line to be 10 millimetres by 10 millimetres. And then I'm going to select circle. And this is going to be a normal line here. I want this to be six millimetres. And so what these construction lines have now done is I can now change the positioning of this circle. If I just randomly clicked and placed it, it's not going to be defined very accurately where it is. I'm just going to do the same on the other side. I'm going to create a rectangle as a construction line and make it 10 by 10 millimetres. Then draw a six millimetre circle on it. I finished that sketch. And now I'm going to select this circle and this circle because you can select multiple shapes to make an extrusion at once. I'm going to hit extrude. And now instead of adding, I'm going to remove. And as you can see, that's going to swing it the other way. And I can drag this out and cut a hole all the way through like so. Now I can define the depth here like so with what's called a blind hole, but I could also say I want to select a face to go to. So now I select this one and it will cut exactly to that face. And this is just an example of there being so many unique tools and settings in here that you can use.

And now I think the last thing we're going to do is add these chamfers here. So we're just going to go back and we're going to select all the edges that we want to chamfer. You can either select the chamfer tool first and then select the edges or you can select the edges and then select the chamfer tool and select the tool up here. And that's a bit too sharp for us. So I'm going to say, I think, how about three mil, maybe a little bit more, a bit more. That looks good. Sweet. And now that is our part all nice and modelled up. And all we would do is we would keep creating more and more parts to build up our assembly.

So I just sketched out this profile of this aluminium bar here. Sweet. And then I made another one of it. And then I made this sketch around the bar. I extruded it out, added some chamfers to it to kind of make it a bit more nicer looking. And then I use the mirror tool, which is up here. And I kind of just copied it over to the other side and then doing the process we did before I modelled the arm. And then instead of remodeling it all, I simply just copied and pasted it down below. And then I created this new sketch on the inside of it, extruded that out, then made some more sketches on it. And I just kept repeating this process over and over till I had a mockup of my project.

Now, something definitely worth knowing about, you might not use it all the time, but for projects like this, you definitely will is the assembly studio. So we've been making something in the part studio and you kind of make all the individual different parts of your project and then you take them and put them all together. And this is done in the assembly studio.

So instead of modeling each part another four times, I just copied them over like so. We're not going to be covering it in this video. This is just about learning how to model your parts because that's the important step for getting them printed or laser cut or CNC routed.

But in the assembly studio, you can also go ahead and put joints on your project. And as you can see, that's kind of how the chassis is going to move. And we just created a whole bunch of joints to put all these pieces together and we can just see what it's going to look like. And that is our crash course on CAD modeling.

So where to from here? Well, the best way to learn CAD is just through experience. It really is a skill that you just learn with lots and lots of practice. If you want to learn through some more tutorials, linked on our course page is some really good follow along tutorials from Onshape. Or you could just jump into trying to model a part of your project, whatever you need to just get going and model something.

Just be aware we have only scratched the surface here. What we have covered is just the essential tools needed to get started, but there are so many more tools available that do really cool things and they are all definitely worth investigating. And if you don't know what a tool does, a quick Google search of it will give you thousands of tutorials on how to use it.

We've now gone from a pen and paper sketch to a nice digital design, and I'm quite happy with how it looks. So I'm probably going to go ahead and get it 3D printed off. There are a few things we need to do to our model before it gets printed. We'll cover that in 3D printing week, but we're now another step closer to finishing our project.

Go and practice modeling now, like right now. Don't click on the next YouTube video, open Onshape and get some practice in now. All right, see you next time.