Join John Helfen for an in-depth discussion in this video Inserting and modifying edges, part of Autodesk Inventor 2018 Essential Training.
- [Voiceover] On the screen, you can see the model we've created up to this point. If you've been following along, your model may look significantly different from this, and that's just fine. If you're catching up, and you wanna start from here, I've created the Modify Edges.ipt you can start from. And what we wanna do here, is talk about how we can modify edges of this model. And we're gonna do that by starting out editing this form. We can go to the browser and double click on the form, to enter the freeform environment, and we're back to where we can edit this form.
As we rotate around and look at this, you'll notice that the bottom of the model is curved, and that's from when we originally created this base T-spline form. It created a rounded bottom, and that's not necessarily what I want here. I'm gonna show you a couple of ways you could manipulate this to make changes to it. The first way would be to insert additional edges, or make modifications to existing edges. I'm gonna go ahead and double click on this edge in the middle, which will select the entire loop, all the way around the model.
And I can right click, and select Edit Form. Now if we rotate to look at it from a sideview, if we use the manipulator, and grab the arrow on the top, and left click and drag down, you'll start to see the bottom curvature become more square, or more sharp. That would be one way we could make a modification to this model, to square off the bottom a little bit, but in doing so, we've dramatically changed the overall ergonomics and shape of this model. That's not what I want. So I'm gonna use the Undo button here, on the heads up display, and then I'm gonna go ahead, and cancel this command altogether.
The reason for that is, what I'm gonna do is, to keep this shape, I'm gonna go ahead and right click on this selected loop, and I'm gonna select Insert Edge. What that does, is it's going to insert an additional edge into the model, so that we can have better control over the overall shape. There's a couple things to call out here though. By default, there's a Simple mode selected. What this means, is Inventor is going to have a bias towards exactly what you told it to do.
It's going to insert an edge, period. Whether or not the shape ends up looking the way you want it to, is irrelevant. It's gonna be biased towards, "Yes, I'm gonna do exactly what you told me to. "I'm gonna insert this edge, "and I'm gonna update the shape to account for that." The other option here, is an Exact option. The Exact option, is exactly opposite of Simple. It's gonna bias towards the form, rather than the edge. So it will go ahead and it will insert that edge, but it will insert additional edges if needed, in order to keep the form, as you see it on the screen.
Let's go ahead and try both. I'm gonna keep it on the Simple mode, and we're gonna look at this location. Notice that this isn't a distance, this is a value. What this is, is a percentage, between the edge that was selected, and the next edge that it finds. So by setting it to .5, I'm at 50% between this edge, and this bottom edge. Now I'm gonna go ahead, and just simply hit OK, and what you'll see, is that we inserted an edge here, but the form did change shape a little bit.
Let me undo by right clicking and selecting Undo, and you can see that small change. I'm gonna go up to the Quick Access Toolbar, and Redo that, and you can see that one more time. Let me toggle back and forth. So inserting that edge using the Simple mode, went ahead and inserted the edge, but it did it in a way where the form changed. Let's go ahead and double click that edge one more time, and you'll notice that I'm in a position where it undid that change, and I'm gonna right click, and I'm gonna select Insert Edge again, and this time, rather than use the Simple mode, let's use Exact.
When we select the Exact mode, remember, what it's gonna do, is it's gonna try to keep the form exactly in the shape you see on the screen, and insert as many edges as needed, in order to accomplish that. So if we select OK, you'll see that many additional edges were created, in order to insert this edge, but maintain that shape. It's exactly the shape we started with, but there's additional edges controlling it. Depending on your need, one or the other may be appropriate. Let's go ahead and look at that from the back, and let's toggle the Undo and Redo again.
Here you can see, if we Undo and then Redo, we get the edge, and you can clearly see the form has not changed, but we get all these additional edges. So really, it's your choice, as the designer, depending on what you're building, and how much work you've put into this, to make the decision on the type of edge you insert, and what mode you use to do that. There's another way to do this as well, and it's a way that I actually prefer, in this case. What I'm gonna do, is I'm gonna rotate so that we can see the bottom, and I'm gonna double click on this edge at the top, I'm gonna hold Shift down on my keyboard, and I'm gonna work my way around the model, double clicking to select until there's a branch.
I'll double click here, and I'll double click here. I now have all of those edges around the bottom of the model selected. With those selected, I'm gonna right click in the Graphics window, and I'm gonna select the Crease option. You can also find it in the Modify panel, here in the ribbon bar, at the top in the middle. But I'm gonna use it from the right click menu, and I'm gonna select Crease. And what you can see, is it has creased, or made a hard edge, all the way around the bottom. What that means is we now have a flat surface on the bottom, and edge that runs all the way around the loop.
What we can do now, is we can rotate around, and look at our model, make sure it looks the way we want, and it still does. All it did, was it took those edges, and pulled them flat to the bottom of the model, and creased this edge. The reason for that is, if we finish this form, and return to the modeling environment, as I mentioned in some of the introductions, in some of the earlier portions of the course, this digital clay, this T-spline form, still lives in Inventor's mechanical world. What that means is, once you exit that editing environment, you can select edges on the model, as if it was created with traditional methods.
And you have the option to apply fillets and chamfers, and this case, let's go ahead and fillet this. If we look at it from the right, with an eighth-inch fillet, it looks pretty nice and smooth. I'm gonna go ahead and rotate around a little bit, just to see that, and I'm gonna go ahead, and click the green checkmark to apply that change. Now you'll see that fillet run smoothly all the way around the bottom of that model, and it's the same radius all the way around. The nice part about this is because we're in a parametric modeling system, Inventor will allow you to edit that form and make changes.
If we return to the form in the browser and double click it, we could then right click, select Edit Form, and then we could select this edge for example, and drag it out to the left. Once we do that, we can click the green checkmark to apply it, and get out of the command, and when we finish this form, and return to the modeling environment, Inventor has automatically updated, or recalculated that fillet, so it follows that edge that we just updated. That's not really what I want, so I am gonna right click and select Undo. I'll Undo again, and Undo a third time, to return to where we are, but I wanted to show how you could go ahead and make modifications, and have Inventor automatically update all the features after that.
- Reviewing interface changes
- Projecting and importing geometry
- Working with Autodesk AnyCAD
- Understanding part modeling
- Building parts with placed features
- Working with partial chamfers