Building a Swing Seat Sketch While Using Arc Tools and Centerlines for Precision and Symmetry

In this video we will create the seat for our swing set and in doing so we are going to explore some of the arc sketch tools and the differences between each of them. All right, this is more or less what our swing seat is going to look like. Let's go ahead and open up the sketch to get a little more insight onto how that was made.

We've got a center line that separates the space between one swing and the other swing. We've got dimensions setting the height, the thickness, the curvature of that swing set,  and the more or less the size. 12 inches encompasses about half of what that swing set is going to be.

Great, we've got all the information we need. Let's go ahead and do this together. All right, first things first, I need a plane to draw my sketch and I'd like that plane to bisect this beam.

Let's create that now. Reference geometry, plane, select one surface and the opposite surface. Perfect.

Close that out and on this plane we're going to create this sketch for our seat. Again, we want two swing sets that basically are equidistant from each other and from their outside frames. Let's find the exact center line,  the vertical center line between this part of the frame and this part of the frame.

We'll grab a center line, grab that angle here, that corner, grab this edge. All right, there we go. There's the exact middle.

We'll have one swing live in this space and one swing live in this space. I'd like to also find the exact center of this space. I'm going to grab a center line again and then just grab this line and this edge.

There we go. Just for cleanliness, I'm going to bring this all the way down. Perfect.

Our swing is going to be bisected by this line. Now, the first thing we want to do is establish what the height of that swing seat is going to be above the ground. Let's grab a center line one more time, connect it from this line to this edge, and then set a dimension.

In this case, we're going to do 30 inches. Great. Next, let's start building the profile sketch of that swing set.

To do that, I'm going to go to three-point arc. We're going to have to establish three points to make that arc. The first will be where these two lines cross each other.

The next will just be arbitrary out here to the left. The third is going to basically set the curvature for us. I'm going to highlight this center line and this arc by holding shift and then make them tangent to each other.

Now, I want this to curve around on itself because it's going to hold on to a wire. We'll do that by going to tangent arc. What this does is the moment that you start a tangent arc,  it's going to create a new arc that is tangent to the line or arc that already exists there,  the one that it's touching.

There we go. We just need one, so we'll hit escape to close it out. Let's set the width of this seat and more or less the height, thereby setting the curvature.

Smart dimension. Click this dot in the center of that circle. This line, we'll set that to 12 inches.

Looks like it's having an issue with that. Let's go ahead and see what's going on. Now, we can shift it.

Sometimes SOLIDWORKS gives us an issue with our smart dimensions,  even though it's actually perfectly appropriate. Here's what we're going to do. If you're running to this exact same problem, delete the dimension, grab a central line, establish the line that's going to describe that dimension.

Then maybe SOLIDWORKS might have an easier time dimensioning this line instead. Let's see here. There we go.

We just had to move the line a little bit. Now, let's go ahead and grab another smart dimension and establish the height of the seat. There we go.

Now, let's loop this around a little bit, see how that looks. Now, this seat doesn't have any thickness, so let's give it some thickness. We'll use offset entities to do that.

We'll go to offset entities, select the line,  and it should select the entire path. Make sure that it's offsetting inside that curvature. We'll set it to 0.375, which is three-eighths.

Close it out with a green check mark, and it's starting to get there. Let's go ahead and grab a regular line and connect this dot to this dot. We will also connect this dot to this dot, thereby closing our sketch.

We'll bring this curvature around just a bit. We still have a few things to establish. The first is what this inside circle diameter is going to be, and that's going to be dependent on the wire that goes through it.

Now, let's assume we're using a three-eighths inch diameter wire. Let's make this three-eighths,  or maybe even just a hair above. Let's make this three-eighths, 0.375. Lovely.

The last thing to establish is where this arc ends. I want it to be parallel to this line,  more or less. Why don't we just create a centerline connection from this point to this line, and then from this point to this line.

Make them equal to each other. That should be enough. If you need to, you may have to establish a tangent relationship between the line and the arc, and this line and this arc.

That should be enough for us for right now. Let's go ahead and figure out what this depth of our seat is going to be. I'm going to close out this sketch,  bring that over to the side, reopen our reference sketch or our reference model.

I'm going to grab a dimension here, six inches. All right, we're going to close that out. I'm going to go ahead and highlight the sketch, extrude boss base.

For this, it's going to be mid-plane, and we'll set that to six inches. Uncheck merge result, although there's nothing you would merge with anyway in the first place. It's still a good practice to be in.

We'll close that out. This is a new body, so let's go ahead and highlight it green. There we go.

Save your work, and that's it for this video. If you have any questions,  the next video, we're going to use 3D Sketch to build the wire that's going to hold that swing seat.