Let's Go Design Episode #5: Chassis Design and Assemblies

In the last episode, we discussed weldment features and sketch techniques. This time, we move closer to the final overall CAD design of our Hot Rod Baby Buggy. We watch as Jeremy hot-wires the golf cart motors to show how the aluminum tracks perform flawlessly.

In this episode, Jeremy takes us through:

The Overall Design: Jeremy shares 80% of the CAD design, complete with a 3D model of a dad placed in the center. He shows us the fenders, talks about key components underneath the buggy, and creates a battery compartment using sheet metal.

Sustainability: We use SolidWorks® Sustainability to compare material selections for the fenders of our buggy - sheet metal vs. plastic.

The Assembly: Jeremy shows the basic build and sub-assemblies. He puts together the steel base weldment, aluminum floor, components from the golf cart’s electrical system and finally powers the tank treads.

Watch Episode #5 now at LetsGoDesign.tv

How to automatically take a picture using a catscript

Catscripts can be a powerful tool when needing to automate processes in CATIA V5. One common process which is helpful to automate is when you want to take a screenshot of a .catpart or .catproduct with a white background (to put into a powerpoint or Excelfile). This sounds like a daunting task if you are new to VB programming. I find the best thing to do is to break down this large, challenging project into smaller, more manageable tasks. Let's think about each stage we want the macro to complete:
1. Reframe on the part
2. Hide the specification tree
3. Change the background color to white
4. Take a screenshot and save it as a JPEG file
5. Change the background display color back to what it was
6. Unhide the specification tree
Now, if we take each of those steps one at a time it's not so big of a problem. I'll be explaining each of these steps in the next couple of posts starting with step one today- how to automatically reframe (or fit all in) on the part in CATIA. We'll create each step individually then combine them all into one CATScript at the end.  This tutorial will also help you learn visual basic programming and will help you write your own CATScripts.
First, go to Tools>Macro>Macros. Click "Create" and change the Macro language to CATScript. Enter a name for your macro. Copy and paste the following code.

Language="VBSCRIPT"
Sub CATMain()

Dim specsAndGeomWindow1 As Window
Set specsAndGeomWindow1 = CATIA.ActiveWindow

Dim viewer3D1 As Viewer
Set viewer3D1 = specsAndGeomWindow1.ActiveViewer

viewer3D1.Reframe

Dim viewpoint3D1 As Viewpoint3D
Set viewpoint3D1 = viewer3D1.Viewpoint3D

End Sub

What does all of the above actually mean? A CATIA VBA program or “macro” consists of a
“Subroutine” named CATMain(), called out with the line Sub CATMain(). Variables are “dimmed” (declared) and then “set” (given a value). Variables are “dimmed” as a type. A type is either a “primitive” type (single, double, integer, string, etc.) or an object type (more complex). 

Stay tuned to learn more in our next article... 

Quick Tips: How do you measure an angle in SolidWorks?

The measure tool will give you the angle - but there is a quicker way.  If you click on two planar surfaces, the status bar at the bottom of your screen should provide an angle.  This also works with two linear lines or edges.

Quick CATIA Tips: Avoid zoom on the specification tree

One annoying aspect of using CATIA is when you attempt to click one of the little plus signs in your specification tree but you miss and accidentally click a branch instead. Your models goes a shade darker and when you try and zoom in on your model it instead makes the tree get enormous or extremely tiny. To turn this option off simply go to Tools>Options>General>Display>Tree Manipulation. Disable the tree manipulation option by unchecking the box. Now this will prevent unnecessary tree zooming. If you still need to zoom in or out on the tree in this mode hold Ctrl while scrolling the mouse wheel instead.

Quick CATIA Tips: How to export the specification tree

I've personally never had to use this before but I can think of many applications where it would be extremely useful, especially in case where your customer or client may not have access or licenses for CATIA. To Export the Specification Tree go to Save As and select text file. You will get a text file that contains only your specification tree.

Quick CATIA Tips: Increase the number of Undos

Did you know that you can control the number of times CATIA will let you hit the undo button? This is a good tip if you are dealing with a large or complicated part model. The default number of undo levels is ten. In some cases it can be very useful to have a few more, but do remember that this will hog system memory so show restraint when altering this setting. Here's where the option is located:
R16: Tools > Options: Select General > Performances.
R18: Tools > Options: General > PCS

CATIA Quick Tips: How to create an axis system within a geometrical set

Another common CATIA question is how can you make a new axis system under a geometrical set and not the default axis system node? Well, to create an axis system in a geometrical set, when you create a new axis, in the dialog box, simply unclick the check box next to the "under the axis system node" option. This will place your new axis under which ever object you have defined as the current in work object. Easy, eh?