Crafting a Complex Slide Pathway Using Projected Curves and Sweep Features in Solid Modeling

In this lesson, we are going to create the extrusion that makes up the main feature of our slide. I've rolled up my own personal model to show you what that looks like. As you can guess, this is a sweep feature that is following this pathway outlined in blue.

This is made up of something called a projected curve. Now, because this moves freely in space, we could use a 3D sketch to create this. The problem is, we like our 3D sketches to be really well defined with tight references and dimensions, and because the slide pathway moves so organically, that would be very difficult to do with a 3D sketch.

So instead, we're going to create what's called a projected curve,  which is the projection of a top view sketch and a side view sketch laid on top of each other to bundle up and create this 3D sketch that you see in space. Here's the side view, and then here is the top view. Great.

So let's do that now. All right. First, let's go ahead with the top view sketch.

I'll go to the top plane, or any plane parallel to the top plane for that matter,  but we're using the top for this course here, and start a sketch. The first thing I want to do is convert the entity that represents the hole that the slide is ejected from. So I'm going to convert this circle,  and you can see it manifests as a simple line on the top view.

That's totally fine. Let's make a construction geometry and go from there. All right.

Now, let's bring ourselves normal to that top view. Great. I'm going to use a center line to find the exact middle of that line and create a center line moving out.

Let's set the general profile of what that top view is going to look like. First, I'll turn this center line into a regular black line, and let's give it a dimension. I'll call it 12 inches.

All right. Next, I could use an arc tool to bring this slide pathway out, but I want something a little more organic. So instead of an arc,  I'm going to use this sketch tool called a spline, and you have three choices here.

Let's pick the one at the very top. We'll start the first click at the end of that line, and then the next click just over to the left here. Escape closes out.

Now, it looks like a line, but if I click on it,  I see these curvature arrows pop up, and I can click them and drag them and affect the curvature of this spline. Now, for this slide, I want something nice and smooth,  a nice descending arc. So the first thing I'm going to do is highlight the spline itself and highlight this straight line, make them tangent.

The next thing I'm going to do is grab my line tool, start it at the edge of the spline, making sure it's horizontal,  pull it out, make that horizontal line and the spline tangent to each other. This is a nice smooth line that I can adjust the curvature of. This obviously would be way too tight here, and this obviously would be way too tight in this direction.

So let's just pick something nice and smooth in the center. Now, let's start dimensioning out what we've just created. I'm going to call this horizontal landing strip a 36-inch length.

We'll make this 72 inches away from the beginning of our slide, that center line here. Perfect. And then from this line to the beginning of, again, this landing strip here, we'll make that 60 inches.

Now that we've done that, we'll do one last adjustment on our curvature. Now, you will find that your adjustments to curvature will not be exactly the same as mine. What that means is once we both create our slides,  we will likely have slightly different volumes of our solid body in our part file moving forward.

That's okay. Remember, so long as we have volumes that are within a few cubic inches of each other,  we should be all right. But once we have volumes that have disparities of several cubic inches,  like we're talking 10,20,30, you may have to go back and correct some previous features.

The most important thing, as you know, is the number of bodies in your part file. The volume,  although important, is not as important. This is great curvature.

Let's go ahead and close that out. All right. That's our top profile sketch.

Let's create our side profile sketch next. And we can just do this on the right plane. I'm going to click N again so it's oriented appropriately.

The first thing I want to do is use center lines to guide exactly where the changes of curvature occur in my side profile sketch. I created an arbitrarily placed vertical line here. I'm going to grab this bottom vertex and this vertex here at the end of this straight line and make them coincident.

All right. Drag this line all the way up so it's easy to see. Let's get another center line.

Make sure it's vertical. Grab this line. Grab the beginning of that straight line.

Make those two vertices coincident. And we'll just drag that right up. One more time.

Grab that bottom vertex and this vertex here. Rather, let's do this outside vertex here. Holding shift, make them coincident and drag it all the way up.

This is more or less what that would look like. Now, we need to know exactly where the slide ejects. Is it up here? Is it down here? Is it somewhere in the middle? Well, let's convert the entities of that circle that we cut earlier.

Creating a line. I'm going to hide everything else. I'm going to make that line construction geometry because it's not going into our feature.

And then I'm going to make sure that our first line ejects out the exact center of that line that we just made. So I'm going to create a horizontal line out in space. Make sure I have the new line that we just created.

Looks like it's having trouble grasping just that line. So I'm going to create a converted entity off of that edge and highlight that edge and the beginning of this central line here and create a midpoint relationship. I'm going to highlight that edge again and turn it into construction geometry.

Perfect. Essentially, you want your line exiting essentially where the center of this circle is going to be on the right plane. All right.

Now that we've done that,  take this construction line and drag it so it stops here. Highlight it. Toggle off for construction,  making it a solid black line.

And let's grab our spline tool one more time. Start it at this line and then just end it right here arbitrarily towards the bottom on this construction line here. Highlight the spline.

Highlight this line. Holding shift. Make them tangent.

Next, I want to establish the exact angle by which this crosses this construction line. So the first thing I'm going to do is I'm going to create a new construction line starting at the end of that spline and kind of moving off this direction. I'll make that construction line and the spline tangent to each other.

And then I'm going to set an angle relationship between this construction line and this vertical line at 20 degrees. Now we simply need to set the height of this dot from the ground. We'll set that to 24 inches.

Great. And just like before, let's use our splines to adjust the curvature so it's nice and smooth. We don't want any kinks anywhere.

The smoother, the better. And that will be based on your best judgment. Once you've got something that you believe works, go ahead and close out your sketch.

All right. Next, let's go ahead and make sure our sketches are visible. We're going to take this side profile sketch and this top profile sketch and combine them to make a projected curve that moves freely through 3D space.

We'll go to Insert, Curve, Projected. And we'll select this side profile and this top profile. And you can see it's ghosting in the pathway of our slide.

From the side, it matches perfectly. From the top, it matches perfectly. This is the curve we are looking for.

Let's go ahead and click the green check mark, closing it out. Save your work. Now, a few things happened.

The first is it created this blue line here that moves organically through space. This is our projected curve,  as shown here in our Feature Manager. The second thing is our side and top profiles disappeared.

They have been absorbed into our projected curve. If we need to alter the curvature in any way,  we'll need to go into the sketch or sketches that affect that curvature and modify those sketches. For right now, it's looking pretty good.

So, let's use this to make our sweep. Save your work one more time. Now, we'll go to Sweep Boss Base.

Well, before we do that,  let's go ahead and create the profile of our sweep. We'll start a sketch on this surface. And we'll highlight this outer circle.

Convert Entities. Close it out. I'm going to hide this reference sketch, so I just see this circle.

Beautiful. Now, we'll go to Features, Swept Boss Base. The sketch profile is going to be this circle sketch that we just created.

The sketch path is going to be this projected curve. There we go. It's ghosting in what that feature is going to look like if we approve it as is.

I'm almost ready to select this green check mark. The last thing I want to do is go to Options and uncheck Merge Result. Let's go ahead and close that out.

Okay, that's looking great. Let's go ahead and save our work one more time. The last thing we're going to do is hollow out the inside of this tube that we have created here.

For that, we're going to go to, in the Features tab, Shell. The first thing we're going to do is set the thickness of our wall after it's been hollowed. Before, we were establishing a two-inch thickness for our slide material.

Let's do that again here. The next thing we're going to do is select each and any of the faces that are not going to be part of the hollowing process. Let me show you what I mean.

I'm going to close this out,  right-click on this, and select Isolate. We're just seeing this piece right here. I'd like you to do the same.

We're going to go to Shell. Make sure this is set to two inches. And for this face, if I were just to select this face here and select Show Preview,  and maybe close it out, it hollowed everything up to this surface.

It went ahead and created a wall thickness down here. Well, that's not what we want. We want this to be cut open as well.

To fix that, we'll go into our Shell, and we will also select this face. Any face you select gets cut through completely. Everything else becomes a wall thickness,  to put it simply.

Once we've done that, close it out. Exit Isolate. All right, we've got something that's starting to look like a slide.

Let's go ahead and save our work. Double-checking, we have 177 bodies here. We'll continue to do some work on this slide body,  so we won't highlight a green just yet, but that will be coming in a future video.

Thank you. In the next video, we will continue some of the features required to make this slide what it's going to be.