# Tutorial: Loft Addendum and Bridge

Learn to build and repair addendum surfaces using the Loft addendum tool and the Bridge tool.

In this lesson, you will learn how to:
• Propagate the addendum surface by using the Auto create rib locations and Addendum configuration options
• Bridge gaps between addendum surfaces

## Import the File

1. On the File menu, select Import.
2. Browse to the bpillar_mod_w_mod_binder.x_b file.

## Define the Part

Select a part and define the thickness and position.

1. On the ribbon, click the Die Design tab.
2. Click the Part icon.

3. Click the Assign icon.

4. Select the part, shown below in yellow.

5. Leave the Thickness at 0.120 cm.
6. By default, the part is designated as the Bottom Face of the thin solid. In this tutorial, we'll keep the default setting.
7. Right-click and mouse through the check mark to exit, or double-right-click.

## Set the Draw Direction

Adjust the draw direction to minimize the depth and avoid negative drafts with the help of the Depth Box and Draft Analysis.

On the View Cube, click Front to rotate the model to the front view.

1. Click the Draw Direction icon.

2. To display the draw depth, in the guide bar, select Depth Box.

3. To display severe negative drafts in red and marginal negative drafts in yellow, select Draft Analysis.
4. Set the draw direction:
1. Click the Phi Angle arrow.

2. Enter an angle of -3.0 deg.
5. Right-click and mouse through the check mark to exit, or double-right-click.

## Create the Binder

Define a binder for the draw die. In this tutorial, we'll assign an existing surface as the binder.

1. Click the Binder icon.

2. Click the Assign icon.

3. Selectable edges are green. Click one of these addendum start edges.

Because Chain selection is the default selection method, all connected edges are selected automatically and now displayed in dark blue.

Note: By default, the Max Draw Depth (the maximum distance between the part and binder) is displayed.
4. Assign the binder:
1. In the guide bar, select Binder.
2. Select the surface (Extrude #2), outlined in yellow below.

5. Right-click and mouse through the check mark to exit, or double-right-click.

Let's create multiple addendum surfaces with the Loft tool using the Tangent selection option, and then propagate them using the Auto create rib locations and Addendum configuration options.

1. Create the first addendum surface:
1. Click the Loft icon.

2. In the guide bar, for the selection method, choose Tangent selection. Now when you click an edge, the tangent edge is also selected automatically.
3. In the guide bar, select Addendum Start Edges. Then select the addendum start edges shown in the video.
Note: The binder for the addendum is implicitly assigned from the selected edges.
4. In the Control Panel, for Auto create rib locations, select All Vertices. Ribs will be automatically created at all vertices, points, and locations on the part edge. This includes vertices on the edge, T-intersection vertices, and discontinuity vertices.

5. Zoom in on the rib shown in the video and delete it.
6. Select the other rib shown in the video, and change the Addendum configuration to Auto Decide Tangency.
7. Right-click and mouse through the check mark to exit, or double-right-click.

Video 1: Create Addendum Surface #1

1. Create the second addendum surface:
1. Click the Loft icon.

2. In the guide bar, for the selection method, choose Tangent selection.
3. In the guide bar, select Addendum Start Edges. Then select the addendum start edges shown in the video.
4. In the Control Panel, for Auto create rib locations, select All Vertices.

5. Right-click and mouse through the check mark to exit, or double-right-click.

Video 2: Create Addendum Surface #2

1. Create the third addendum surface:
1. Click the Loft icon.

2. In the guide bar, for the selection method, choose Tangent selection.
3. In the guide bar, select Addendum Start Edges. Then select the addendum start edges shown in the video.
4. In the Control Panel, for Auto create rib locations, select All Vertices.

5. Right-click and mouse through the check mark to exit, or double-right-click.

Video 3: Create Addendum Surface #3

1. Create the fourth addendum surface:
1. Click the Loft icon.

2. In the guide bar, for the selection method, choose Tangent selection.
3. In the guide bar, select Addendum Start Edges. Then select the addendum start edges shown in the video.
4. In the Control Panel, for Auto create rib locations, select T-intersection vertices. This includes T-intersection vertices and discontinuity vertices.

5. Right-click and mouse through the check mark to exit, or double-right-click.

Video 4: Create Addendum Surface #4

1. Create the fifth addendum surface:
1. Click the Loft icon.

2. In the guide bar, for the selection method, choose Tangent selection.
3. In the guide bar, select Addendum Start Edges. Then select the addendum start edges shown in the video.
Note: To reselect the addendum start edges, in the guide bar, select Clear Selection , and then select different addendum start edges.
4. In the Control Panel, for Auto create rib locations, select All Vertices.

5. Right-click and mouse through the check mark to exit, or double-right-click.

Video 5: Create Addendum Surface #5

1. Create the sixth addendum surface:
1. Click the Loft icon.

2. In the guide bar, for the selection method, choose Tangent selection.
3. In the guide bar, select Addendum Start Edges. Then select the addendum start edges shown in the video.
4. In the Control Panel, for Auto create rib locations, select All Vertices. Ribs will be automatically created at all vertices, points, and locations on the part edge. This includes vertices on the edge, T-intersection vertices, and discontinuity vertices.

5. Right-click and mouse through the check mark to exit, or double-right-click.

Video 6: Create Addendum Surface #6

## Bridge Gaps Between Addendum Surfaces

Now we'll bridge gaps between the addendum surfaces with the Bridge tool and adjust them using the Constrain and Shape Factor options.

Gap #1

1. Bridge the first gap and fine-tune the shape:
1. Click the Bridge icon.

2. In the guide bar, Rib 1 is automatically selected. Leave the selection method as Chain selection. Select the first rib. Right-click to confirm.
3. Select the second rib.
The surface in between is created.
4. Select the first rib. In the microdialog, under Constrain, select Tangent. The bridge surface is made tangent to the selected rib's adjacent surface.
5. Select the second rib. In the microdialog, under Constrain, select Tangent.
6. Right-click and mouse through the check mark to exit, or double-right-click.

Video 1: Bridge Gap #1

Gap #2

1. Bridge the second gap and fine-tune the shape:
1. Click the Bridge icon.

2. In the guide bar, Rib 1 is automatically selected. Leave the selection method as Chain selection. Select the first rib. Right-click to confirm.
Note: To reselect the first rib, in the guide bar, next to Rib 1, select Clear Selection , and then select a different first rib.
3. Select the second rib.
The surface in between is created.
4. Select the first rib. In the microdialog, under Constrain, select Tangent. The bridge surface is made tangent to the selected rib's adjacent surface.
5. Select the second rib. In the microdialog, under Constrain, select Tangent.
6. Right-click and mouse through the check mark to exit, or double-right-click.

Video 2: Bridge Gap #2

Gap #3

1. Bridge the third gap and fine-tune the shape:
1. Click the Bridge icon.

2. In the guide bar, Rib 1 is automatically selected. Leave the selection method as Chain selection. Select the first rib. Right-click to confirm.
3. Select the second rib.
The surface in between is created.
4. Select the first rib. In the microdialog, under Constrain, select Tangent. The bridge surface is made tangent to the selected rib's adjacent surface.
5. Select the second rib. In the microdialog, under Constrain, select Tangent.
6. Right-click and mouse through the check mark to exit, or double-right-click.

Video 3: Bridge Gap #3

Gap #4

1. Bridge the fourth gap and fine-tune the shape:
1. Click the Bridge icon.

2. In the guide bar, Rib 1 is automatically selected. Leave the selection method as Chain selection. Select the first rib. Right-click to confirm.
3. Select the second rib.
The surface in between is created.
4. Select the first rib. In the microdialog, under Constrain, select Tangent. The bridge surface is made tangent to the selected rib's adjacent surface. Change the Shape Factor to 2.0.
5. Select the second rib. In the microdialog, under Constrain, select Tangent. Change the Shape Factor to 2.0.
6. Right-click and mouse through the check mark to exit, or double-right-click.

Video 4: Bridge Gap #4

Gap #5

1. Bridge the fifth gap and fine-tune the shape:
1. Click the Bridge icon.

2. In the guide bar, Rib 1 is automatically selected. Leave the selection method as Chain selection. Select the first rib. Right-click to confirm.
3. Select the second rib.
The surface in between is created.
4. Select the first rib. In the microdialog, under Constrain, select Tangent. The bridge surface is made tangent to the selected rib's adjacent surface. Change the Shape Factor to 2.0.
5. Select the second rib. In the microdialog, under Constrain, select Tangent. Change the Shape Factor to 2.0.
6. Right-click and mouse through the check mark to exit, or double-right-click.

Video 5: Bridge Gap #5

Gap #6

1. Bridge the last gap and fine-tune the shape:
1. Click the Bridge icon.

2. In the guide bar, Rib 1 is automatically selected. Leave the selection method as Chain selection. Select the first rib. Right-click to confirm.
3. Select the second rib.
The surface in between is created.
4. Select the first rib. In the microdialog, under Constrain, select Tangent. The bridge surface is made tangent to the selected rib's adjacent surface.
5. Select the second rib. In the microdialog, under Constrain, select Tangent.
6. Right-click and mouse through the check mark to exit, or double-right-click.

Video 6: Bridge Gap #6

## Create the Draw Die

Create the draw die and adjust the radius of the fillet along the edge of the binder.

1. Click the Die icon.

2. Click the Die subtool.

3. Select the binder.