Join Gabriel Corbett for an in-depth discussion in this video Loft tool, part of SOLIDWORKS 2017 Essential Training.
- The loft command is one of the most powerful commands inside of SOLIDWORKS but it does take a little bit more effort to get started using this command. The first thing I need to do is to find a bunch of different sketches that I can use to create the shape. Right now on my screen you can see I've got one little rectangle. Now, what I need to do is create another sketch on another plane. I want that plane to be directly above the top plane that I already have. I'm going to go up to Features, and create Reference Geometry, and go on ahead and get a Plane, and put that directly up above my top plane.
There it is. The distance doesn't matter but I just want to place it about three inches up above. Click on OK and now I have a place to draw my second sketch. Click on that plane, click on Start a sketch, and I'm going to click on Make normal too. All right, this time I'm going to draw another rectangle, click and just drag it out. It doesn't really matter the shape. Just create another rectangle. When I'm happy with my rectangle, go ahead and exit out of the sketch. Now I should have two sketches on two separate planes, one above the other. That's all I really need to start my very basic loft feature.
So, go up here to loft and it's going to ask us for what the profiles are, and if there's any guide curves or types of start or end constraints. So, in the beginning let's go ahead and choose a profile. Now, I can choose it in the window here but I prefer to choose it from this little drop-down feature manager. So, click over here and click on sketch number one, and then go ahead and click on sketch number two. And you can see what it does. It just connects the dots. It says that this corner here to that corner there and this corner here to that corner there. And I also have the ability to grab this little green dot and move it around, and actually twist that structure if you want to, and that can also get you into quite a bit of trouble.
So, let's make sure we snap that back to where we need to be and there it is, a really basic loft right there. Now, let's take a look at some of these start and end constraints. If you want to, you can add some type of a direction vector to how your part is starting or you can add also a normal to profile. It means it's starting straight up out of this profile and it's gonna be converging over into this profile. This little arrow here can adjust the magnitude of how much of that is actually affecting the shape. So, you can bring it up or down or you can even type at a value over here.
The same thing with the end constraint. Over here I can click on either a direction or a normal to profile, and now I get more of a hourglass-type shape, and same thing. With this little arrow here I can drag it down to affect the shape a little bit more or drag it back up to affect the shape a little bit less. And once you have the shape you're looking for, then I can just go ahead and click on OK. There's my basic loft command. If you need to make modifications go ahead back over here, click on it, click on the Edit feature tool, and I can adjust any of these different values.
Now, notice I also have this option called Guide Curves, and I have the ability to add in curves or other sketches that are going to define how the shape transforms from the first profile to the second profile. To do so let's go back and delete this entire feature, and now let's go ahead and create a new sketch. Now, this sketch needs to be perpendicular to the existing sketches we have. So, I'm going to choose a plane like the front plane or the right plane to draw on and start a sketch.
Now, over here I can see everything in 3D and I'm going to start with a line, starting from down here and it doesn't need to actually touch that line. Just make a line and then maybe we can convert that over to, let's say, maybe a tangent arc and come off the end of that, a bit of tangency, and for front let's just make another tangent arc coming off that and get it close to this line up here. Now, here's the secret. If you click on this line here and you click on the end point of this line here, I get this option for pierce.
So, click on pierce and that just connects the two together. You want to do the same thing down here. Click on the point, go on and click on the line, and then click on pierce. All right, now if I look at this normal to or straight on I could then move this thing around, I could adjust how it looks, what the feel of the entire shape is, and this really can be any line or segment of arcs that connects from one profile to the other profile. When you're happy with what you have, go on ahead and click OK, and then exit out of the sketch. All right, so now what we're going to do, I'm going to hide this top plane up here just to make it a little bit clearer so we don't see that one.
So, now we're basically going from the first profile down here to the second profile up here, and we're going to use this curve here to guide the progress from one shape to the other. Back up to Lofted Base/Boss I'm going to do the exact same process. I'm going to choose Sketch number one and I'm going to use Sketch number t wo, and then my guide curve is going to be sketch number three. And notice the entire shape follows that same curve. And there it is. We can add in one guide curve or we can add in 100 guide curves.
We can have two profiles or hundreds of profiles. It's all about how complicated you want to make this shape. So, you can spend a lot of time building very, very complicated lofted features, depending on how many profiles you have, and how many different guide curves you have. So, keep in mind that each profile need to have its own sketch and a certain spacing between them, and then guide curves need to connect those individual sketches together using some type of thing like a pierce relationship between the curve itself and the end result.
Now that we've covered the basics on this one I want to show you a couple other examples. So, let's go up here to 8.1.2 and here's a common problem you'll see when you're creating lofts, and notice I've got a four sided square going into a six sided shape. And you can see it's connecting the dots here. So, it's connecting this corner here to this corner here. This one doesn't have a corner so it just picks the center point of that line up to this corner here and it's not symmetrical and it's a common problem you're gonna see inside of a loft.
I want to define how this happens versus having the computer just figure something out for me. So, I'm going to go ahead and hide the shape here, and then I'm going to go back and just delete this loft altogether, and then come down here to that original sketch. The best to be able to control the shape of the loft is to make sure that all of your objects have the same amount of corners. So, in this case here I've got a six corners and down here I've only got four. So, I need to add a couple more corners to my rectangular shape down here. So, edit the sketch and I'm going to go ahead and click on Normal to.
I'm going to create a line and just use a center line, and go from one side to the other. Then what I'd like to do is break this line into two pieces. So, I have a line here and I have a line there. Now, I can do that a couple ways. I can just turn this into a construction line, for instance, and then I can create a new line on top of it. So, just click here, one to there, and then add one to there. Now I have two individual different lines. The other option is to split that line. Now, there's a split line command, however, by default it does not show up here in these Sketch tools.
If you want to turn it on, right click on the Sketch tools tab here, go down to Customize command manager, come over to Commands, come down here to Sketch. And you can see there's actually a bunch of tools in this Sketch toolbar that aren't up here in the ribbon. And one of 'em happens to be this one right here called Split Entities. Click on that and drag it up here and release. Click OK and now I have that tool. All right, now what I wanna do is turn that tool on. Come over here and click right where I want to split it, click OK, and now I've split that into two different entities.
So, I've got a line here and I've got a line here. Now I'll go back, take a look at our shape. So, now we have a definitive. I've going to connect this point here to that point there. I'm going to connect this point here to that point there, and so on. Let's go back to our Loft, Profiles. Now, the way I'm doing it here is I'm selecting it from the tree. If I cancel it out of that, I can actually preselect both of these, by the way, and then click on Lofted Base/Boss, and click on OK, and notice how it's connecting. It's not connecting incorrectly. So, what you can do is you can grab that little green dot and drag it around until you get the shape you're looking for.
In this case, I want that dot there to connect right there. Click OK and now you can see I've got a much more symmetrical shape, and that's the workaround for making sure that you've got equal amounts of points on both your original starting profile as well as your ending profile. I got one more example for you and here's another example of three individual profiles. And I'm going to click on all three of them here, hold down Control and select all three of those profiles, and click on Lofted Base/Boss. Here's another example of a pretty complicated shape.
You can see how it's connecting the dots between these individual shapes. I can then click on these dots and move them around to adjust the profile a little bit further. And you can see there I've taken this shape here, which is a circle, and I have just basically turned or split that circle into individual line segments. So, each one of these segments here, here, and here are individual segments that make up a full circle so that way I could have endpoints that connect the dots together.
Click OK and now you can see I've got a pretty complicated shape going from a square to a hexagon to a circle. Those are the key features for creating lofts. It is one of the most powerful features inside of SOLIDWORKS. It does take some time to set it up and you might need to go back and change it a couple times to get the shape you're really looking for. The keys are using a bunch of different profiles and starting to look at guide curves and end constraints to really get some interesting shapes in your design.
- Advanced Sketch tools
- Creating sketches
- Modeling with the Extrude and Revolve features
- Applying materials, colors, and backgrounds
- Sketching basic shapes and polygons
- Working with planes, axes, and the coordinate system
- Creating smooth and angled corners with fillets and chamfers
- Advanced part modeling with the Loft and Sweep features
- Creating circular patterns
- Using surfaces to build solid models
- Using design tables
- Adding assemblies to drawings
- Including a bill of materials