New Feature: Playlist Center! Pick a topic and let our playlists guide the way.

Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member

Adding control to a loft by creating rails

From: Inventor 2014 Essential Training

Video: Adding control to a loft by creating rails

We can now continue looking at the Loft command, but this Now that we have those in place, we save ourselves To create the rails, we're going to create a new By doing that, we have the end points of these lines, touching the outside I'm going to leave these as solid reference lines, and this If we go to the Spline drop down and select Spline Interpolation.

Adding control to a loft by creating rails

We can now continue looking at the Loft command, but this time we're going to add a additional intelligence by creating rails. In the previous video, we simply lofted through three shapes, and then we used some of the options within the dialogue box, for the loft to control the overall shape. And how the 3D model transitioned through the profiles that we selected. We can get more accurate control by creating rails. To do this, we're going to take the model we created in the previous video.

And we'll hover over the loft in the browser, and right-click on it and select Delete. What we'll see is a dialog box that allows us to select what we're going to delete. By default, it'll delete everything if we click OK. If we uncheck this consumed sketches and features option, it will delete the feature but leave behind all of the sketches and work planes that were created to generate the original loft. Now that we have those in place, we save ourselves some time without having to recreate each of those profiles. To create the rails, we're going to create a new sketch, and we're going to go to the Origin geometry and look for the x,y plane, which is the plane that runs up through the center of the part.

I'm going to go back to our home view, because the next thing we want to do, and this is really critical when you're creating rails. As we want to create rails that intersect each profile exactly. And the way we can do that, is through the Project Geometry function. In the draw panel, there's a Project Geometry option, and, when we select that we can then select each of these profiles. And, it takes the ellipse or the circle and projects it to the flat plane we're currently in.

By doing that, we have the end points of these lines, touching the outside edge of the ellipse and the outside edge of the circle at their tangent points. I'm going to leave these as solid reference lines, and this is going to cause us a problem in a little bit, but I want you to see it, just so you can remember it, and I can show you how to resolve it. But, now that we have this projected, we can look at it from the front view, and we can use the endpoints of that line, to control the spline that will be the rails.

If we go to the Spline drop down and select Spline Interpolation. This is the type of spline that I prefer to use when I am creating loft. Because I think it gives me incredible control over the angle and curvature of the line that I'm using as the rail. I'm going to start the line by hovering over the end point of the projected line in the bottom sketch. I'm going to create a control point in between the first two work planes. I'm going to create a point at the intersection of the midplane. I'm going to create an additional point in between the next two work plains, and a final point at the endpoint of the top circle.

I can then click the green check box, to create this Spline. And if I zoom in on this a little bit, you can see that I have the ability to click and drag on each of these points. And you'll also notice the little gray dots running around near this. These are curvature handles, which by default I try not to use unless I really need that very precise control. But if I do, I can simply click and drag on one of these, and, it will allow me to define more accurately how that line transitions through this specific point.

I'm not going to get into all the detail of customizing that completely, because I actually prefer a little bit smoother of a transition. And, if you get into changing these handles a little too much, sometimes you can make the line look a little less smooth. Now that we have the basic spline shape, we can right-click in the graphics window and select Create Line. To generate a center line that we can mirror this spline around, because you're going to need a rail on each side. And when we create the Loft, you'll see why. Now that we have this line, I'm going to right-click on it, and select Center Line, just so that I have it identified as a center line.

To mirror this spline, I can go to the Pattern panel and select the Mirror option. And by default, I'm entered into the selection mode. I can simply select the line I want to mirror. I can go to the dialog box and select the mirror line selection tool, and, select the line we just created as the mirror. By clicking Apply and then Done, I've created an exact mirror of this spline. And, if I left-click and drag on any of these points. You can see I have symmetry created, that allows me to control the exact shape of the rail on both sides.

Now you'll notice, because I moved this handle, this line has enabled the handle. I'm going to right-click on that and deselect activate handle. What this will do is allow a little bit more of a smooth transition through those points. Now that I have my rails complete, I'm going to finish the sketch. And if we orbit, you can see that essentially what we've done is create to create a wire frame shell around this shape. And it'll allow the Loft command to actually control the exact shape of the loft as it runs through the profiles.

I'm going to go ahead and click the Loft command from the create panel, and. we're ready to continue creating our loft. And we'll start out by adding sections, just like we did in the previous movie. We're going to select each of the profiles that we created. And if we look at it from the front view, you'll notice that it looks exactly like the shape we had previously. If we rotate to the side, you'll see the same is true. And the reason for that is, up to this point we haven't done anything different. We've selected these and last time we just hit Okay, and created that basic shape.

What we want to do now, is add the rails. If you remember when we projected that geometry, I mentioned we were going to to run into a problem and that's fine. What I'm going to do, is I'm going to select my first rail. And, because I'm not getting a preview, there's an indication that something's wrong. So what I want to do, if for example I were to click Create here, I'll get an error. And what the error says, is that I'm attempting to create a loft where the rail, intersects the profile multiple times. And the reason for this, is the geometry we've projected is reference geometry not construction geometry.

So what's happening, is when I click this rail it's running all the way up from the bottom to the top, it's connecting to this projected line, and working its way back down to the other side essentially creating one large loop. To fix this, we can go back to the sketch, sketch four. We'll go back to our home view and if we zoom in, we can right click on each of these pieces of geometry and convert them to construction. By doing this, Inventor will ignore them as part of the loop creation process and allow us to create this loft.

So, we'll go ahead and enter the loft command again. We'll select the profiles that we started with. And we're back to that shape, and now, we'll go ahead and click the Rail option and we'll add our first rail. And you'll look at this from the front, and you can see what's happening. Now the loft is following this exact rail, but what's happening, as it pulls on this side, it's also pulling this side. Because currently, this side is not controlled by a rail. What we can do, is simply add this additional rail, and you'll see the precise location of the shape follows that rail.

And we can click Okay to create our feature. The important item here, is because this is a parametric model, we can always go back to this loft, and modify any of the loft shapes that are created, but we can also change the rails as well. By double-clicking on sketch four, you can see we're back to editing the rails. And if I wanted to make this neck just a hair longer, I could simply click and drag down towards the other profile. Or, if I wanted to, I could make this bottle curve inward.

And have a completely different shape, and by clicking the Finish Sketch, the model is updated to reflect the changes to the rails. This should provide you enough foundation, to create complex shapes in Inventor using the Loft command.

Show transcript

This video is part of

Image for Inventor 2014 Essential Training
Inventor 2014 Essential Training

90 video lessons · 2497 viewers

John Helfen

Expand all | Collapse all
  1. 1m 24s
    1. Welcome
    2. Using the exercise files
  2. 6m 20s
    1. Exploring major workflow steps
      2m 19s
    2. Reviewing different file types
      4m 1s
  3. 22m 3s
    1. Navigating using the ViewCube
      4m 56s
    2. Navigating using the navigation tools
      5m 31s
    3. Using the browser
      3m 34s
    4. Using the ribbon bar
      2m 47s
    5. Using the Quick Access Toolbar
    6. Using the Marking menu
      4m 33s
  4. 22m 6s
    1. Basic menu customization
      6m 40s
    2. Custom ribbon bar panels
      6m 22s
    3. Keyboard
      5m 9s
    4. Marking menu customization
      3m 55s
  5. 20m 24s
    1. Project file introduction
      3m 54s
    2. The project file: .ipj
      4m 4s
    3. Setting up the project file for this course
      7m 11s
    4. Frequently used subfolders
      5m 15s
  6. 22m 31s
    1. Introducing sketching
      4m 55s
    2. Working with origin geometry
      4m 46s
    3. Understanding constraints
      7m 39s
    4. Application options
      5m 11s
  7. 50m 43s
    1. Drawing lines
      6m 29s
    2. Creating rectangles and arcs
      9m 26s
    3. Creating splines
      6m 35s
    4. Creating slots
      5m 43s
    5. Construction geometry
      6m 18s
    6. Dimensioning
      9m 34s
    7. Parameters
      6m 38s
  8. 30m 33s
    1. Move, copy, and rotate sketch geometry
      7m 43s
    2. Trim, extend, and split sketch geometry
      6m 20s
    3. Scale, stretch, and offset geometry
      7m 47s
    4. Creating rectangular, circular, and mirrored sketch patterns
      8m 43s
  9. 19m 27s
    1. Understanding work features
      3m 58s
    2. Creating offset work planes
      4m 17s
    3. Creating work planes
      6m 59s
    4. Creating work axes and points
      4m 13s
  10. 16m 50s
    1. Projecting geometry
      7m 7s
    2. Importing AutoCAD data
      9m 43s
  11. 54m 31s
    1. Part feature introduction
      5m 14s
    2. Creating a base extrusion feature
      8m 46s
    3. Keeping extrusions connected with the To next face/body option
      4m 29s
    4. Creating revolves
      7m 42s
    5. Creating complex shapes with the Loft tool
      8m 50s
    6. Adding control to a loft by creating rails
      8m 40s
    7. Creating a sweep feature
      6m 16s
    8. Creating a sweep feature with model edges
      4m 34s
  12. 24m 44s
    1. Adding holes to a part model
      10m 10s
    2. Modifying edges with fillets and chamfers
      4m 18s
    3. Hollowing parts with the shell feature
      10m 16s
  13. 25m 37s
    1. Creating rectangular feature patterns
      9m 23s
    2. Adding intelligence to a rectangular pattern
      5m 45s
    3. Creating rectangular feature patterns along a path
      2m 22s
    4. Creating circular feature patterns
      3m 11s
    5. Mirroring part features
      4m 56s
  14. 31m 30s
    1. Understanding iParts and iFeatures
      3m 19s
    2. Creating an iPart from an existing part
      11m 0s
    3. Changing between versions inside an iPart
      5m 50s
    4. Extracting iFeatures for use in other parts
      5m 11s
    5. Inserting iFeatures into a part
      6m 10s
  15. 26m 23s
    1. Introduction to assemblies NEW
      1m 59s
    2. Placing components NEW
      7m 40s
    3. Creating components in the context of an assembly NEW
      8m 9s
    4. Placing fasteners from the Content Center NEW
      8m 35s
  16. 46m 14s
    1. The Mate/Flush constraint NEW
      9m 42s
    2. The Angle constraint NEW
      5m 34s
    3. The Insert constraint NEW
      3m 55s
    4. Driving constraints NEW
      10m 0s
    5. The Transitional tab NEW
      3m 50s
    6. The Motion tab NEW
      9m 18s
    7. Contact sets NEW
      3m 55s
  17. 18m 38s
    1. Adding materials to parts in an assembly NEW
      4m 3s
    2. Visual styles NEW
      4m 52s
    3. Enhancing the design experience with shadows NEW
      2m 9s
    4. Adding a ground plane, reflections, and perspective to a design NEW
      3m 34s
    5. Changing the lighting style to match a design NEW
      4m 0s
  18. 39m 11s
    1. Exploring initial drawing creation NEW
      5m 6s
    2. Placing base and projected views NEW
      9m 31s
    3. Creating section views NEW
      8m 0s
    4. Creating detail views NEW
      3m 56s
    5. Creating a breakout view NEW
      5m 41s
    6. Creating auxiliary and cropped views NEW
      6m 57s
  19. 25m 57s
    1. Creating general dimensions NEW
      9m 20s
    2. Changing dimension precision NEW
      4m 21s
    3. Creating baseline, ordinate, and chain dimensions NEW
      5m 51s
    4. Creating baseline, ordinate, and chain dimension sets NEW
      6m 25s
  20. 10m 43s
    1. Creating individual balloons NEW
      4m 34s
    2. Creating a group of balloons with automatic ballooning NEW
      3m 40s
    3. Adding a parts list to the drawing NEW
      2m 29s
  21. 30s
    1. Next steps

Start learning today

Get unlimited access to all courses for just $25/month.

Become a member
Sometimes @lynda teaches me how to use a program and sometimes changes my life forever. @JosefShutter
@lynda is an absolute life saver when it comes to learning todays software. Definitely recommend it! #higherlearning @Michael_Caraway
@lynda The best thing online! Your database of courses is great! To the mark and very helpful. Thanks! @ru22more
Got to create something yesterday I never thought I could do. #thanks @lynda @Ngventurella
I really do love @lynda as a learning platform. Never stop learning and developing, it’s probably our greatest gift as a species! @soundslikedavid
@lynda just subscribed to all I can say its brilliant join now trust me @ButchSamurai
@lynda is an awesome resource. The membership is priceless if you take advantage of it. @diabetic_techie
One of the best decision I made this year. Buy a 1yr subscription to @lynda @cybercaptive
guys (@lynda) is the best. So far I’ve learned Java, principles of OO programming, and now learning about MS project @lucasmitchell
Signed back up to @lynda dot com. I’ve missed it!! Proper geeking out right now! #timetolearn #geek @JayGodbold

Are you sure you want to delete this note?


Thanks for signing up.

We’ll send you a confirmation email shortly.

Sign up and receive emails about and our online training library:

Here’s our privacy policy with more details about how we handle your information.

Keep up with news, tips, and latest courses with emails from

Sign up and receive emails about and our online training library:

Here’s our privacy policy with more details about how we handle your information.

submit Lightbox submit clicked
Terms and conditions of use

We've updated our terms and conditions (now called terms of service).Go
Review and accept our updated terms of service.