January 27, 2012

ACA Structural Member Styles - Part 2

First Article in the Series (Structural Member Catalog)

Structural Member Wizard
Sometimes you need a Structural Member Style for a standard shape which is not in the Structural Member Catalog. Or perhaps it is early in the design process, and you have an approximate size for a steel shape, but not an exact size. Rather than pick an exact section, you would like to create a generic member as a placeholder until the structural design is finalized. For these cases, the Structural Member Wizard can speed the creation of the necessary Structural Member Shape Definitions and Structural Member Styles. Access the the Structural Member Wizard on the Manage ribbon tab, by selecting the title of the Style & Display panel to expand the panel and choose the Structural Member Wizard tool on the flyout.

The Structural Member Style Wizard dialog has three "pages". On the first page, you select the Member Shape, from a list of standard shapes in three categories: Concrete, Steel and Wood.
The left pane of the dialog shows a schematic sketch of the standard shape selected, and indicates the dimensions over which you will have control. The illustrations that follow are based on the Steel, Wide Flange (I) shape, but all work in a similar manner.

With the desired member shape selected, select the Next button to advance to the second page, where you will enter the dimensions that will be applied to the Member Shape to be generated.
Most of the values will be shown on the sketch in the left pane; any that are not, such as E - Weld Radius, should be evident from the description. In this case, the Weld Radius is the radius of the fillets between the web and flange. When the values are set as desired, select the Next button to move on to the third page.

On the third page, you specify a name for the Structural Member Shape Definition and Structural Member Style to be created. The page also gives you a summary of the shape type and associated parameters, with the values you entered. Review these to verify that they are correct. You can use the Back button to return to either of the previous screens and make any changes, if needed. When you are satisfied that all values are correct, select the Finish button on the third page to generate the definition and style.

You can check what was created by opening the Style Manager (on the Manage ribbon tab, on the Style & Display panel, select the Style Manager tool). Under the current drawing in the left pane, expand the Architectural Objects node, and then expand both the Structural Member Shape Definition and Structural Member Styles nodes. You will find that a shape definition and a style using that shape definition have been created using the name you specified and the Member Shape selected and the geometric information entered in the dialog.

Next article in the series (Manually Created Structural Member Shapes)

January 19, 2012

ACA Structural Member Styles - Part 1

AutoCAD® Architecture provides a number of ways to create Structural Member Styles. This series of articles will take a look at the various options.

Structural Member Catalog
If you are trying to create a Structural Member Style for a standard steel section, or for a typical concrete or timber member, you will want to make the Structural Member Catalog your first stop. The parameters for standard structural members, both Imperial and Metric, are already stored in the Structural Member Catalog, waiting for you to make use of them. Access the the Structural Member Catalog on the Manage ribbon tab, by selecting the title of the Style & Display panel to expand the panel and choose the Structural Member Catalog tool on the flyout.
The Structural Member Catalog is composed of three main sections.
  1. The upper right pane will display an image related to the part of the catalog you are currently viewing.
  2. The left pane is the navigation pane. By expanding the appropriate nodes in the tree structure, you can drill down to the part of the catalog that contains the member of interest.
  3. The lower right pane displays the data associated with the node selected in the left pane. While in the upper level nodes, you can also double-click on an item in the lower right pane to open that node and see its contents.
For example, suppose you needed to model a W24x76 steel beam. In the left pane, expand the Imperial, Steel, AISC and I-Shaped nodes, and then select the W2n, Wide-Flange Shapes item. You will see a list of the AISC wide-flange steel shapes from W21x44 to W27x258 in the lower right pane. Scroll down in that pane until you see the W24x76 member.
Now comes the really hard part. Right click on the the W24x76 member, and choose the only item on the context menu, Generate Member Style.
In the Structural Member Style dialog, give the Style a name. The name defaults to the designation for the member, in this case W24x76.
Once you are satisfied with the name, click OK. You can create as many additional Structural Member Styles as you need. When you are finished, close the Structural Member Catalog by clicking on the "X" in the upper right corner.

You can check what was created by opening the Style Manager (on the Manage ribbon tab, on the Style & Display panel, select the Style Manager tool). Under the current drawing in the left pane, expand the Architectural Objects node, and then expand both the Structural Member Shape Definition and Structural Member Styles nodes. You will find that a shape definition and a style using that shape definition have been created using the name you specified and the geometric information stored in the catalog.
Next article in the series (Structural Member Wizard)

January 12, 2012

ACA: Model Views and Annotation Scale

I made an interesting discovery yesterday, that may explain why I have occasionally had issues with viewports where the viewport scale and the annotation scale for the viewport are different. I suppose most people are a little more laid back than I am, and tend to draw on the Model "tab" without a lot of regard for how things will end up on the final sheet, and then compose the sheet on a Layout "tab" by eyeballing the corner points of the viewport, pan model space to get the target area roughly centered, use the scale control to set the viewport scale and then pan and/or adjust the viewport extents to suit. I like to think about how what I am drawing will eventually appear on a sheet, and work out how much of a sheet will be required for the drawing at hand. This often results in a non-plotting polyline in model space defining the extents of a particular drawing or detail, and I generally create a Model View of those extents, so that I can later create a viewport of the corresponding dimensions and restore that Model View and be done.

Yesterday's discovery was that I finally noticed that Model Views retain the annotation scale that is current at the time the Model View is created (when using the VIEW command). I did this while using ACA 2010; it may also occur in 2008 and/or 2009.
In the image above, you can see a Model View that I created of the area bounded by the yellow rectangle. This area is intended to be shown at 1/2" = 1'-0" (1:24) on a sheet. I "forgot" to change the annotation scale from the initial default of 1/8" = 1'-0", however, and so the Annotation Scale property of the Model View is 1/8" = 1'-0".

After drawing an appropriately sized viewport on a Layout tab and using the VIEW command to restore the Model View I created in that viewport, the viewport scale is correctly reported as 1/2" = 1'-0" on both the Viewport Scale control on the Drawing Window Status bar and on the Design tab of the Properties palette.
The Properties palette also reveals that the annotation scale associated with that viewport is the 1/8" = 1'-0" that was saved with the Model View. In most cases, having different viewport and annotation scales is not desirable. Note also that if you restore the Model View on the Model tab, the annotation scale will also be changed to that saved with the Model View. If the area is meant to be plotted at a particular scale, having that scale saved with the Model View would help automate getting the right scale associated with annotative content added as well as getting the the right scale when restoring the Model View in a viewport. So I am making a mental note to try to remember to set the annotation scale prior to creating a Model View. But can a Model View created with an incorrect annotation scale be fixed?

Unfortunately, the View Manager dialog does not provide a way to change the Annotation Scale property once the a Model View is created. You can rename the Model View, update the layer snapshot saved with the view (if any) and edit the boundaries of the Model View, but, as you may be able to tell from the gray background in the first image, the Annotation Scale property is not editable. I had hoped that while editing boundaries, that I would be able to change the annotation scale using the control on the Drawing Window Status bar, but that control is disabled when editing boundaries. In order to change the scale, you have to recreate/redefine the Model View, with the correct annotation scale set current prior to the redefinition. This is a fairly straightforward process, but it does require you to reselect the Model View boundaries.
  1. With the Model tab current, set the desired annotation scale.
  2. Start the VIEW command. In the View Manager, select the Model View to be recreated in the left pane, and then select the Name in the middle pane and copy the name to the clipboard. (You can skip this step if you are willing to type in the exact view name in the next step.)
  3. Click the New button. In the New View / Shot Properties dialog, paste (or type) the view name in the top edit box. Make any other changes to the settings in the dialog as desired.
  4. Click the Define view window button (or select the Define window radio button) and define the area of the Model View.
  5. Click OK in the New View / Shot Properties dialog. Choose Replace in the View - Already Exists dialog.
  6. In the View Manager dialog, note that the Annotation Scale property for the redefined Model View now matches the current, desired annotation scale.
  7. Click OK to dismiss the View Manager and register your changes.
  8. Return to the Layout tab and restore the redefined Model View in the viewport. Notice that now that the correct annotation scale is associated with the Model View, the viewport gets the correct annotation scale when the Model View is restored.