Fusion 360 Sketches, Dimensions, and Constraints


In this video, we’ll be going through how to do sketches in Fusion 360. So this is the starting window that gives you a blank template to work with. And in the top left corner here, you will see the creativity sketch selection. Once you pick that, you can then decide which plane you’re going to want to draw the sketch on. And if you mouse over each one, it will visually show you the grid. So I will select the X, Y plane here. And this is the scale interface. You’ll notice that the toolbar up top has changed, uh, when you are not in sketch mode and I’ll click finish just so you can see what that’s like. You see a lot of different options. Whereas when you are actually in a sketch, it changes to match what you will be performing in the sketch itself. So we’ll start off with a line and this one’s pretty straightforward.

You can either click once and then move your cursor to the second spot that you would like to have your line end up and then click again. And you’ll see, we’ll actually continue. And if you want to exit out of that and not draw a second line, you can just push escape. You can also push L on your keyboard, which is the shortcut for it. And you’ll notice that if I click and drag, you will have the same effect, but it will actually draw an arc instead of a line. So this is actually pretty cool because you can make it a very fluid workflow if you’re having both lines and arcs in your drawings. So I’m going to undo that arc and next, I’m going to move over to the square, which is this second one is there say two-point rectangle. The hotkeys are, if you’re wanting to draw one of those.

And what I like to do is click on a spot. That’s in one of the quadrants around my origin and then click on the opposite quadrant. So you’ll notice that I’ve drawn this square that has its origin in the center of it. And the reason why I like to do this is that a lot of my dimensions are all referenced off of a single point. So we’ll go into that with constraints a little bit later, but again, the rectangular squares, similar to the line where you can either click twice. Yes. Or you can click and drag and then click again either way. It’s going to make you look twice at the rectangle. Um, but there you go. Another thing you can do is when you’re drawing a rectangle or even a line, if you’re in the middle of clicking, you’ll notice that it has two numbers on it.

It has the one in the horizontal direction and the one in the vertical direction. If you actually type while this is highlighted. So let’s say I want that to be 2.5, five inches, and then I can push the tab and then change that one. Let’s say to you 1.25, and then that will make my rectangle already dimensioned, right from the beginning from one. Yeah, Andrew, it will get into the dimensioning for the rest of these as well, but there you can rectangles or squares without dimensions, or you can create them with dimensions. I will drag my left mouse button to highlight all of them and delete them. The next is going to be a, now again, this, I like to send her on the origin, but first I’ll show you without centering it. Click-drag out to the diameter of your circle. Now, this is different from other modeling software.

I believe it’s solid works that have you do the radius when you first drive circle, uh, this is the diameter here. So again, I can either click or I want to draw another circle and then type in the diameter. I can type in 1.5 and then push enter. And it pre dimensions that circle. Now I’ll do only the origin as well, just to show you that it can then be censored along with the origin. And you’ll notice here that once I’ve done that, I started the circle on the origin and drew out at a 2.2, five diameter, and it turned black. These other circles are blue, and this one is black. And that means that this particular shape is fully constrained. What that means are these other ones I can move them around this one. I can not because it is constrained to be on this origin.

So you’ll see if you mouse over here, I can click on this and it won’t really tell you what it is, but that is a constraint. Um, that is the coincidental constraint, which means that the center of that circle is matching the specific location of the origin. I also cannot change the diameter because I’ve already dimensioned this, whereas this other circle up here has no diameter dimension and no, so coincidental constraint, I can now change the diameter of this just by dragging it. So are, is pretty important in sketches because a lot of times, if you’re wondering why something is changing while you’re modeling it, or while you’re dimensioning other parts, it’s probably because it’s not a constraint. So if I were to delete this dimension, I can then see that the circle. So can you get larger and smaller into constraints in a little bit?

The next one on the list is going to be this point spline. Now this one is not one that I very often, but it’s at least useful to know that it’s there in case you are in need of it. You can click and then it looks like you’re drawing a line at first. Once you click again, watch I moved this cursor around and it actually creates a continuous flow from line to line. Now, if I go further vertically, it’ll actually make that swoop deeper. And then if I got closer, it’ll make it shallower. So really this is designed to make continuous lines and you’ll watch if I click on this again only if this third segment affecting the second one. It’s also affecting the first one. So they’re all connected together. This fourth segment is still impacting the first one and it’s because it’s trying to make these as fluid as possible and watch if I mouse over that, it turns it into a nice round little gel.

So pretty cool function. A lot of the stuff that I’m on all is not necessarily going to be following that sort of a requirement. Um, that’s my origin is still there. All right, so the next one on here is going to be a mirror. So I’m going to draw a couple of shapes. We’ll draw a rectangle, we’ll draw a circle, and then we’ll go ahead and draw a line as well. You might not make it some sort of a triangle. So this mirror allows you to select objects and reflect them across a particular access axis. So if I highlight all of these, you can see that I’ve got 16 objects selected. Again, I can highlight them one by one, and let’s say, I only want to do a few of them. And there are five currently selected here, but I’m going to go ahead and select all of them.

And then mirror line. Then lets you mirror off of a particular axis. Now you’ll notice here that I can’t actually see any axes here on this left in the tree. I have to unhide this origin, and now I can see these. So when I click on this axis, it’s going to now mere those, okay. Cross that y-axis tonight. I see I’ve got those all lined up. And if you move the left side of the source side mirror side is going to also change with that as well. So this is fairly useful if you want to make something that symmetrical and a lot of times it’s useful, but sometimes you may not see that this is a feature that’s relevant to the design that you’re doing. Okay. All right. So now onto dimensioning, so I’ll go ahead and create a square here, and then we’ll create one here.

You’ll notice that these dash lines start showing up. That means that it’s trying to constrain what I’m currently sketching to another object. So I’m going to not do that so that I can show you some constraints here. And then let’s go ahead and make a couple of circles of varying sizes. All right. So before we get into constraints, we will do dimensions. So dimensions are fairly simple. You click on this dimension icon, or you can push D and there’s a couple of different options that you can do. For example, on this square, I can select on this corner point and then this corner point, and that will give me a vertical dimension. You click and type in the number. Let’s just say 1.6. And that side is now dimensioned. Now, instead of clicking the two points, I can directly select this line here. And that will also dimension that line automatically.

And I’ll just type in a number. Now, if you want to dimension, let’s say for example, corner to corner, I can do this as well. But if I try to do that, that it says adding this dimension will over constrain the sketch, choose okay. To create a driven dimension. This means that that dimension that I was trying to make is actually defined by the other two dimensions that I previously made. So if you take that 1.6 and that 1.25, those are actually going to calculate this number that is going to show up. So if you click, okay, 2.03 inches is what that is going to be. And that is a driven dimension. And those show up in parentheses. Now, if I double click on one of my other dimensions and let say, make that another 1.6, it will change that driven dimension to 2.263, which is the value of the corner to corner distance based on those other two dimensions.

So I’m going to delete that for now. Those are useful when you get into parameters and that’s something that we will talk about it for video, uh, for now, let’s continue with dimensioning on different objects. So circles, there are really only two things that you can do with this. You click on the outs outside part of the circle, and this is your radius. Do it again on one of the other ones, you just click it. Your mouse button is released and you place this wherever. You’d like your dimension to be on the screen and then type in your dimension and push enter. And there you go. The second thing that you can dimension about a circle is really it’s positioned with relation to something else. So for example, I will click on the center of this circle. And right now I’m looking for another object too, you mentioned this too.

I’m going to select the origin here, and you’ll notice something different about this. This is a diagonal distance, but we moved too far to the left. It now becomes a vertical distance. And then if I move too far up, it becomes a horizontal distance. So this is important because if you want, let’s say you’re making a quadcopter, for example, and you want the center of the, prop or the center of the rotor to be a certain distance from the center of your drone. Then this is the way you would want to do this. To have it be 2.6, 2.8, whatever the dimension is or the center of that rotor. Now let’s see, say you’re making something that has a screw hole that has a certain distance from the center of your object. You may want to have a horizontal or vertical distance, not necessarily in that order, uh, from the center.

So we’ll just have that be one inch. And then you can also define that from object to object. So let’s say I want these two circles also to be one inch apart. You can see select the center of two circles and it will dimension between them, the desire dimension that you put. Another thing that you can do is you’ll notice that this dimension is crossing the path of another. That’s not necessarily a bad thing, but I like to keep them a little bit cleaner and have them be inside so that it’s not so much crossing paths. Um, you know, you look really weird if you had a dimension that was sitting up like this, and it’s not very easy to read. So if you just keep that semi-close to where the dimension Lee is, then you can make your sketches a lot cleaner. So last thing before we do the next part after dimensions is you can actually do angles on here.

So to do that, I’m going to create lines that are just a random, um, shape. Um, and there’s nothing to about this. So if I pick one of these, I can move the lines. I can move the points. I can really do anything I want with this shape. I can move it around. So now I’m going to do dimension and angle. So let’s say I want this bottom part to be a certain angle. The way I did that was I pushed on the dimension key or D clicked on one line, which you’ll notice that this is trying to dimension this line already. Let’s say, I want to do an angle. I can click on another line. That’s adjacent to it. And now it gives me an angle. So let’s say I want that to be 120 degrees that is now 120 degrees. So no matter which way I try to move this thing, that dimension will always be 120 degrees.

The next thing I’m gonna move on to is going to be constraints because you see a lot of these little icons here next to the objects that I’m creating, and those are constraints. So let’s jump into this list here. The first one is the coincidence constraint. This means that two points or lines or points are going to be on top of each other in relation to the coordinate system. So for example, if, I exit out of that and I just take this little dot this point here on the corner of the square, and I drag it around, let’s say, I want it to be right lined up with this. Now, generally, fusion is going to snap these in place. So you’ll notice that as I’m moving this around, it kind of snaps right to that corner, or I can keep it on this line pretty clean, but let’s say you don’t really want to drag stuff around like that.

I can click on this coincidence constraint and click the first point, which is usually the one that it will move to reach the second point. So if I wanted to move this corner up to the first one, I would have to have clicked them in a different order. So I clicked that corner there, and then I’ll click this one and it moves those to be a coincidence. Now, if I try to move anything about this shape, those corners are always going to stay together. So the same can be done with the center of a circle or this point with any other points, such as a rectangle or a shape. So if I select the circle and I want to make it coincident with the point that’s on this polygon, I then click that second point and it makes them a coincidence. So again, if I move any of these shapes around, those are always going to stay coincident with each other.

Uh, the same can be done with the origin as well. So if I click on any object, I can also click on the origin and it will make that coincident. Uh, the next one is going to be vertical and horizontal. This is useful, both for points and for lines. So if I click on the vertical-horizontal constraint, I can then select any one of these lines that has nothing next to it. And you’ll let us set this one down here. Your has this shape, that’s kind of like a cutting board. No, I’m not sure what to call that shape, but it’s basically, yeah, fixed horizontal surface. Same thing. This one here, this one is vertical. And again, this has horizontal because those are all going to be either vertical or horizontal. So if I click onto one of these sides of this polygon down here, let’s do this.

One is going to make that verdict cool or horizontal. Another reason why it did that is that is it closer to the horizontal plane than it is to the vertical plane? So if this were larger than 45 degrees, it would automatically make it vertical. So this one is going to be pretty close to 45 and it went vertical. So it was, it was over 45 degrees. Now, if I take this and I move this down a little bit, so that it’s less than 45 degrees, and then I select the shape again, it will not make it horizontal. So a lot of variabilities that you can play with. Um, and that’s, that’s how I use it for lions. It’s for points. Uh, let’s say I want to have the point of this polygon be directly vertical in relation to the origin, or even another point.

I’ll click on the origin as the second point. And you’ll see that that will directly line itself up underneath the origin or where I move these lines in the shape of that point is always going to be directly vertical. Then on the next one is going to be the tangent to constraint. And I think I’m going to draw another square just because I don’t want to have that before, too messy. So we’ll draw their square and others, tangent constraint is going to make a line or the line that is involved with on the shape B tangential to the circumference of the circle. So you can either click the circle or the line first here, I’m going to select the line. And then when I click the circle, you’ll notice that we’ll bring the line to the circle, making them tangent. Now it looks like it made it to a point, but if I move this line to extend this rectangle here, you’ll see that that is perfectly tangential to this circle.

The next one, what is going to be equal. And this is going to make either two radii or two lines equal in their dimension. So let’s say I want this rectangle here to be the same exact size as this rectangle here that has already been dimensioned, but I don’t want to read dimension this one separately. I can select the top line here and this line here, and it will, I’ll make this top line of this square equal to the dimension of the width of this square. The same thing with this site, I can select either the left or the right, because at this point they’re both constraints to be, uh, these top lines that are horizontal. And so these left and right sides are going to be the same dimension. So if my second point I click on this line, I’ll notice that it made that square perfectly the same size as the square.

And when I moved them, they moved together because if I try to extend it this side out, the scores already locked in, this square is all so equal in all aspects. Uh, I’ll go ahead and do the Eagle on the circles as well. So this circle is 1.5 and this one is 1.25. Let’s say, I want this tiny one down here to be the same size as this 1.25. I’ll select either one because this 1.25 inch is not going to change unless I changed the dimension and then select the second circle. And this one is now larger. Now I can drag this up here and you’ll see that they actually overlay perfectly and comment down below. If you understand why this polygon is dragging this giant spike up with here, I have mentioned that there’s a particular constraint that makes those two points coincide. So we’ll just test you out there a little bit to see if you’re listening.

Now, the parallel is a constraint where you can make two lines. Perfect. [inaudible] parallel. So lets these ones crossing or even not crossing. I can just have them be kind of next to each other. I can select the first line, which is going to move to match the second in line. Actually, that was vice versa with most other countries. It’s the first one that moves. And you’ll notice that it brought those in parallel. I can change the length of these lines. I can change the position, but they’re always going to be parallel. Now I’ll show you again on this one, parallel with this arbitrary line to here. And again, that is all the same. Now you can always mix constraints. So if I want all these lines to be equal, I can see select the two and they are now equal to nine. So I make one longer.

The other one’s going to get longer. Their positioning is going to be kind of weird because there’s really nothing. That’s tying these to any services, terrific spot. Uh, I can make the points horizontal to each other. So all of these lines are going to always be horizontal and they’ll always be the same length. Uh, I’m not sure why he would really want to do this, but you can make little dancing lines. Uh, the next one is going to be perpendicular. So I’m going to do something with these three up here. That’s going to change a lot with just two clicks. So perpendicularity is making one line, having a 90-degree relationship with another line. So if I click that and then have it be perpendicular to the top of this square, I’m on, there we go. It is now you’ll notice that it changed all of these lines.

That’s because all these other constraints that are here that really don’t serve any functional purpose, other than having those lines be an example, made all of this perpendicular to this line. So now they’re floating here. Now, what if I want to have those be actually attached to the circle down to a point I can have this coincidental constraint tie these two together for me. So this one will always be colinear with that line. Now that brings me to another point, no pun intended. Uh, I’m going to jump to this colinear relationship here, which now makes me able to select two lines and have them be directly in line with each other. So when I did that, this time, the rectangle here and the top of the rectangle here are now one single line passing straight through. And you’ll see that if I draw a point from here to here that at zero degrees. So those are directly horizontal. That can also do the same as having a horizontal constraint from one to the other, but ever you want a line to match where another line is, and they’re not horizontal or vertical. This is very helpful to do that.

So the next one is going to be the midpoint. And I actually don’t click this button a whole lot because I use a hotkey for it. So when I’m on this line here, you’ll notice that it turns blue. And if I get close to the middle, nothing really happens. Now I’m going to hold down the shift key and watch what happens. I get towards the middle and nothing. Okay. And usually, that happens. So I’m actually going to go to a coincidence point here and now you’ll see that when I told you to shift, I sh I see an X there with a triangle. That triangle means point. So if I select that, I can now use that midpoint to make another selection. So right now I’m doing the coincidence constraint. I’m not going to on this line here. And that line will always be attached to the point of that particular line.

Now this will work for dimensions as well. So if I push the D key for dimension, then I select that midpoint. I can actually dimension what the mid-point of an object would be. But again, this one will be over-constrained because that line has to be equal to this line here. Uh, but you can use that midpoint feature for constraints and all that. So four dimensions, uh, this cemetery one is going to be an interesting thing because I don’t know if I have an object that will work for that, but we’ll try it out anyway. Uh, and if I’m going, to be honest here, I usually use the mirror function rather than the symmetry, but again, there’s a place for everything. You just kind of figured out what your workflow is, and what’s going to work best for models that you’re going to make.

So I’m going to make things symmetrical here. So I’m going to click on this circle and then click on this circle and then click on this axis. Now you’ll notice that the bottom one moved over here in this polygon is all jacked up, but those two are identically symmetrical similar to a mirror as if I would have done a mirror across this axis. So if I move one, this one will also move in relation to the axis. So that is what I’m going to go ahead and end it with for today’s video. There are a lot of other options. If you click on create, you can see many different things. You can have different types of circles. You can have arcs polygons, which are actually kind of cool, very, very simplified. Uh, you can, let’s say I want a half-inch polygon that is 12 sides or that’s a terrible example.

Cause it looks like a circle. Let’s do eight sides, right? You can actually make those pretty simple with that. So we’ll dive deeper, um, ellipses, slot splines. These are all really great functions. Circular patterns are great for gears or any type of screw system that you want to have around a central point, like another screw or a shaft. Um, the rectangular patterns. These are all very useful tools. Modifications. We’ll get into those later because that’s a little bit more of an advanced sketching technique. At least in my opinion. Now I’m used very frequently. And then with constraints, there are a couple in here that we did not necessarily use, uh, but I don’t use them a whole lot. And I’ve been using this for about three or four years now. So, um, we’ll dive in a little bit deeper there. So just a little bit of an in for next time.

Uh, I’m gonna go ahead and delete all of those. So here’s what you can do with sketches, right? So I will make a circle and I will make a square and let’s go ahead and just make a fun little polygon just for kicks and giggles. Um, except let’s move it because I don’t want it to overlap my circle. So once you finish your sketch, you’ll actually see here that it’s just chilling there on a plane. Now there are so many things that you can do, but I’ll do one to be kind of silly with it and then show you what actually you would normally do with a sketch. That’s kind of like this. Uh, if I click revolve here and select a bunch of shapes and then click an axis, it will, then it didn’t like that because, uh, it doesn’t like to revolve around the funky shape.

Um, so there you go. So you can make shapes out of a simple sketch, not sure what you want. So we do with this, but I’m sure you could 3d print it and it would be fun. Um, then you can also make objects that extreme. You can cut, which again, this is a really odd thing to do with, with that, but to end things off here, just going to, to extrude the simple shapes and there you go, your sketch has now become a 3d object. So I hope you learned something from this video is a very simple approach to sketching infusion 360, we’ve touched on some dimensions, touched on constraints. It’s really the groundwork for everything that you will be doing in terms of modeling. And you can’t do anything without sketches. So this is just in the interface of the solid. Again, here, there’s more surface mesh sheet metal, there are all sorts of lots of different options that you can do that sketching is going to be where you do all the groundwork for your solid models. So thanks for watching the comment down below with any questions. If you, you have the answer to the question that I asked earlier, toss that down there below as well, subscribe for more videos, and thank you for watching.

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