13. Profile Member Spans

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In this tutorial, we’ll see how to create two assemblies that have profile member spans.

The first example will be a rural wooden fence, in which all parts will be based on the same profile.

Draw a 6” diameter circle on the ground and create from it a profile called 6” post. Keep its placement point at the center and assign it a wood material. 

To create the post component, click Build and draw up a 52” high post. 

Make the post a component called 6” post. Set its axes so that the origin is at the bottom center, red goes in the model’s red direction, and green goes along green so that blue points up.

In the Assembly Dialog assign the name Rural Fence. There will be no profile members, so go to the Component tab and add a component named Post. Pick it from the model, keep the default placements, and set a 6’ spacing. Uncheck Max and Horizontal so that most posts will be exactly 6’ apart, and the 6’ can be along a slope. 

This fence will have two rails, so go to Span and add the first one. This will be profile member type span, called Lower Rail 1, and you can pick it from the model using the post component. Its supports are the post component, and keep the default pattern. 

Allow Slope but not Curve, and the center of this post will be 14” off the ground.  Click Build to see how it looks so far, and keep it selected so you can implement changes.

We want the rails to sit in front of the posts, so add a 6” Left / Right offset.  To leave a bit of space between rails, add a 1” start and end setback. 

For the upper rail, click the Add icon to copy the lower rail, assign its name, and change the vertical offset to 3’.

Now let’s change the look of this fence to have an alternating rail pattern. Change both spans to the first alternating pattern. 

With the Lower Rail 1 span showing in the Dialog, make a copy which is placed on top of the original rail, and name it Lower Rail 2. This span will have the other alternating pattern. Do the same to copy the upper rail. 

To build this type of fence, the rails need to extend past their posts. So for all four spans, change both setbacks to -6”. 

Save this assembly, and load it into a model that has a path like this. Select the path in a counter-clockwise direction and build. The spans follow the slope where the path is sloped.

To change what happens at the two junctions, open Component and add a 30” junction setback for the posts on either side of the junctions. By default, no rails are placed across junctions.

So go back to Span and and check Cross Junctions for each span. 

Our second example starts with this electrical tower, which is a component. Its origin is at the center of the base, its red axis points toward the assembly path direction, and the dimensions listed are from the component origin to the point where the electrical wires will connect to the tower. We’ll need these dimensions later when entering offsets for the wires, which will be profile member spans.

This model also has a small circle profile which will be used to define the profile member spans.

In the Assembly Dialog, assign the name Electrical Towers. There will be no profile members that follow the assembly path. In the Component tab add a component named Tower and pick it from the model. Place these components all along the path, and set the spacing at 60’ max.

Next open the Span tab and add the first span. This will be Wire 1 - the lowest wire on the tower. There is no wire profile member defined, so click Edit Profile, zoom in and select the wire profile, and add this as a profile named Wire. Its placement point will be top middle, and assign it a red material, to be easier to see. 

Supports are listed as the tower components since there is only one component. For Pattern, keep spans between all components, and allow slope so that wires can follow a path in 3D. Leave Allow Curve unchecked, because wires will follow a straight path between towers. Set an 8’ sag, and keep Divisions at 10. 

To raise the wires up where they need to go, enter the 8’ 8” Left / Right offset, and the 40’ Up / Down offset. 

To test things out, select a curved path like this, and build. 

Let’s say that these towers are supposed to be facing the other way. You could change their axes, or start over and select the assembly path in the reverse direction. But this time, go back to the component and rotate them 180 degrees. After applying changes, the towers turn but the wires remain in place.

To fix this, go back to the span and glue it to its supports. 

Now you can add a new span, called Wire 2, which is a copy of Wire 1. The only change is the vertical offset of 52’. And a third wire will have an offset of 64’. After applying, here is the completed electrical tower assembly: