From Sketch to Solid: Understanding Planes, Constraints, and Volume Creation in 3D CAD Design

Hello, in this lesson we're going to get in further about building a cube and the relationships between planes to sketches to volumes. So I have here in front of you are a series of entities that I have created. They're more complex than the last as we can see.

Now, each of these creations shows up as commands in our design manager over here at the left. I'm going to open up this first sketch and what we can see here are four separate entities with different characteristics. The first is a vertex or point.

This is simply an infinitesimal point in space. It doesn't represent any type of entity that can be turned into any type of solid volume. It just exists.

This is the vertex. It happens to be a vertical line. And what makes the vertex is two points being connected by a single line.

It's still not enough to make a volume, but it's more complex than what we saw in the point. This is an arc. This is a vertex which also exists as part of a larger circle.

With every arc, there is a center of that arc or circle that can help us to manipulate the arc itself. And then this squiggly line here to the right is what's known as a spline. And a spline is essentially a series of complex parabolic arcs that can be used to create organic looking designs like we see here.

I'll select escape to get out of this. Here we are. I'm going to close this sketch without saving it by pressing this X in this top right hand corner.

All right. Now here is the surface. A surface is a closed shape that has had a surface stitched over the top of it.

It's also known as a plane if it is completely flat. In this case, it is. And something with 3D dimensionality, height, width, and depth is known as a solid volume.

We can also have surface volumes if say we were to delete one of these faces. There we go. We can make that volume empty.

Or if we didn't delete a face, that volume could remain solid. I'm going to go ahead and press this section view to show us that that volume is solid all the way through. Now, as you work in SolidWorks, we're going to be working with all of these different types of entities.

And the way that we build these entities begins with a plane. We build all our sketches on a plane. Now, there are three planes that come automatic in every profile.

The front plane, the top plane, and the right plane. Those planes are connected by something known as the origin, which is a point in space with a 0,0, 0, X, Y, Z location in space. Now, to begin a sketch, we'll need to first select a plane, which can be one of these three, or a plane that we created, or a completely flat face as a surface shown here, or one of the flat faces of this cube.

We'll select that surface or plane. In this case, I'm going to select the front plane. The moment we select the front plane, we're given an option to create a sketch on that front plane.

I went ahead and select the sketch button, and now we are working in a sketch of that front plane. We know we are in a sketch because in the top right-hand corner, those buttons reappear. Once you've saved the sketch in its current form, and once you've closed the sketch without saving, I'm going to go ahead and close this sketch without saving.

The first thing I want to do is clear my graphics area of all this extra stuff. Great. I did that simply by grabbing this blue bar and moving it up the feature tree, thereby suppressing or hiding these commands.

Let's go ahead and select the front plane. Select this first button, which is the sketch button. Beautiful.

Now we are facing the front plane directly. In other words, we are normal to the front plane. I'll go up here to the command manager, here at the very top.

Make sure that I'm selected in the sketch tab, showing all of these sketch tools. I'll go ahead and pick one of these shapes to build. In this case, let's select a rectangle.

I'm going to go ahead and grab this drop-down menu and decide which of these rectangles I want to build. In this case, I'll select a center rectangle. Now you can see my cursor has transformed into a pencil with the center rectangle icon next to it.

That lets me know that I'm getting ready to build a center rectangle. Now the first click on a center rectangle is going to establish the center of that rectangle. And if we drag our mouse out, we can arbitrarily affect the height and width of that rectangle.

A second click is going to solidify where we want that height and width to live. And since we just created this rectangle, if we look over here to the left-hand side,  we have a series of options that affect the parameters of that rectangle. Each one is the drop-down menu.

And we can see we can affect everything from the location of that rectangle,  the height and width of that rectangle. We can highlight any of these cells, put in a new value, and affect where our rectangle lives. There we go.

We just changed the center point along the X-axis. Let's change the center point along the y-axis. I'll go ahead and select one here.

Great. You can explore these options a little bit. But for right now, let's just go ahead and go to the top left-hand corner and click this green check mark.

Okay. We've officially created our first rectangle. Now we can choose to either continue to work on this sketch,  or we can close it by pressing this button, thereby saving the sketch,  or this button, which closes and deletes the sketch so that it no longer exists.

You can see that each of these lines are blue. And what that means is this sketch is undefined, or rather it's not fixed by any means. We know that because we can grab parts of this rectangle and move it around in 3D space.

We're changing the height, the width. We grab the center. We can change the location.

But in SolidWorks, we want all of our sketch to be fully defined. Defined by references or defined by dimensions, right? So let's go ahead and do that now. If we go back up to the Sketch tab and select Smart Dimension,  you can see that my cursor has changed to feature a measurements tool icon.

Now, if I grab one of these lines and move my mouse up and then click again,  I'm given the option to establish exactly what I want that measurement to be. In this case, it's showing some arbitrary number 2.2776 and so on and so forth. I'm going to make that 3. And then you can hit the Enter key to close that out.

But we'll do it over here too. Select the right-hand side. Again, it gives us another arbitrary number.

I'm going to make that one 3 as well. And we'll go ahead and put I in for inches. And we'll click this green check mark.

Another way to close out Smart Dimension. All right. As you can see from my cursor, I'm still in the Smart Dimension tool.

If I click the Escape key, I can get out of that. Now, even though we've established the height and width of the square,  everything is still blue. And that's because it can still move freely in 3D space.

So the last thing we need to do is establish a location of this square so it won't go anywhere. Let's pick one of these points. It could be the center point or one of the corners.

Click it and hold down the mouse and drag it. And I'm going to set it right above the origin. There we go.

It's automatically linked that point to the origin. And once we release the mouse, the entire entity became black. It's black because it is fully defined.

Now we know that because if we try to click and drag it the way that we did before, we simply can't. It's fixed in space. And this is how we want to design our sketches.

We want everything to be fully defined either by a reference,  in this case, coincident or sitting directly on top of the origin or another point,  and defined by dimension, which we use the Smart Dimension tool to do. Now that we're happy with the way this square looks,  we can close the sketch and save it. We'll go to the top right-hand corner, click this icon here,  and we have thus created this sketch.

You can see from the feature tree that it added this new sketch to the feature tree. I'm going to go ahead and delete these unnecessary items now so we can have a nice clean feature tree. Beautiful.

Now it just shows the sketch that we've created. So let's turn this two-dimensional square into a three-dimensional cube. We'll go over here to Features and select this first button,  which is Extrude Boss Face.

Now, once we click that button, it's saying,  wait a second, we need to have a sketch to extrude. So let's just go ahead and flick the sketch that we have. And now we have the beginnings of a 3D shape.

It's yellow because this extrusion is still undefined. We can grab this arrow here and arbitrarily set the depth in either direction, backwards or forwards. If we move this arrow, we can see on the left-hand side that this dimension icon and the number next to it,  it's changing based on how we drag the arrow.

We can drag the arrow to the point that we're happy with,  say 2.55, or we can go ahead and fill in an exact dimension ourselves with our keyboard, click out of it,  and it updates to that new depth that we've established. Great. This is looking good.

We're going to go ahead and close it out with a green check,  saying that we're happy with what we've created. And now we have our first 3D volume, this cube in 3D space. If we look back over to our feature tree,  we now have this new icon that says Boss Extrude 2. Yours might say Boss Extrude 1 or maybe some other number,  depending on if it's the first one you've created or not.

And this dropdown menu shows us the sketch that created that 3D volume. So SolidWorks has already begun to organize our commands for us within the feature tree here over to the left. I'm going to go ahead and highlight this,  slow double-click until I can affect the name,  and we'll just call it Cube.

Great. Everything looks okay. If you like, you can go to File and Save or Save As if you wish to keep this.

But we'll be moving on to more complex shapes in further lessons. Thanks for listening. In the next lesson, we're going to build a bench for the first time.

We're going to change the bench to see parametric modeling in action and look into the Measurement tool and Evaluate tool to see how our 3D volumes are turning out. Thank you.