Working with Arrays - Stoep Beams

So you wish to create a family where some of the components are automatically spaced and where you can change the number of those items e.g. shelves in a bookcase or rafters over a stoep as in the image below:

The first and most important thing to do is work out how you wish the arrangement to be controlled prior to creating the Revit family and then to create the items to be arrayed as separate family components. In this example the rafters were created first and then brought into a new family. Not only does this overcome many problematic issues which can cause the array to work incorrectly,but also it allows the same beam to be used in other families without having to re-create components over and over again.

Creating the Rafter

Start with the Metric Generic Model family template. It’s a good idea to firstly define any additional materials required. Create a new sub-category within the Object Styles to allow control of the rafter Line Weight, Colour,Visibility etc. Then define a new rafter material in the Materials Editor.

As with any family creation the most important procedure is to define the reference planes and apply dimensions and parameters to control them correctly,prior to creating any actual model geometry.

Define Reference Planes for the length, width and height of the beam and set equality dimensions and parameters to control them. It’s always a good idea to test the family parameters at every stage! It saves a lot of hair pulling and tears.

Once the reference planes have been defined and tested, create the beam using Solid Form>Solid Extrusion in the Elevation Front view. Remember to lock the sketch lines to the reference planes as you go.

Finish the sketch and switch to the Floor PlanL: Ref. Level. Pick the rafter and ‘drag’ the sides align with the reference planes in this view and them lock them and then once again test the family parameters to make sure that everything works. Switch back to the Elevation Front view and create the cut-out detail for the end of the rafter using Void Form> Void Extrusion. Finish the sketch and once again test the rafter by changing the family parameters before saving the file.

Repeat the above procedure for the Purlin.

  

Creating the Family Array

Start a new family, again using the Metric Generic Model family template.

Using reference planes create a layout for the beam array as shown below:

In this example the rafters will extend passed the supporting purlins by 500mm ateach end. In the Family Types, create the formula =Length + 500mm. Test the parameters and check to see that whatever the Length is set to, that the Overall Length adjusts accordingly using the formula.

The purlins will also be set so that they are 100mm longer than the rafter array.The two horizontal reference planes set and locked (click on the dimension padlock) at 100mm within the overall width reference planes will control this.

Loadin both the rafter and purlin families into the array model, File> Load from Library> Load Family.

Firstly position and lock the purlins into place. The easiest way to do this is byusing the Align tool.

Select one of the purlins and edit it’s Properties. Within the Type Properties set the Purlin Length to read the Associated Family Parameter for the Length parameter controlled in the array model. Basically, this means that even though the purlin was created with it’s own length control it is now reading the array’s length. Creating the purlin and rafter with their own length parameters means that they can be used at any time on it’s their own in a model and be controlled.

  

Next place and align the first rafter (make sure that the rafter is locked into place). Select the rafter and then select the Array tool. Make sure that the array settings are set to Move To Last.

Click on the first rafter reference place and then the second one. Once again use the Align tool to lock the edge of the end beams into place:

Select the array dimension and create a new Parameter for the number of beams:

  

Finally test the array using the Family Types dialog box.

Source: revitup.co.za