Exercise 5 - Using Geometry Expert

In this exercise you will use the Geometry Expert to create the profile below. Geometry Expert is a good tool to use when you want to create a closed profile. You create profiles with Geometry Expert as if you were walking around the perimeter of the geometry. You will enter rows of information in the Geometry Expert as you create the profile in a clockwise direction.

Create a new file named GEO_EXPERT. Set the machine type to 3 axis vertical mill and the units to mm. Enter the values below for the stock size.

Select the Geometry icon from the Top Level Palette.

The Geometry Palette will appear.

Select the Geometry Expert icon from the Geometry Palette.

The Geometry Expert dialog box will appear.

Each row of the Geometry Expert will have a Feature Type icon on the left side.

Click and hold the mouse down on this icon and the available feature types will appear. They are: Line, Chamfer, Fillet, Clockwise Arc, Counter-Clockwise Arc, Close Shape, and Macro. The Geometry Expert spreadsheet is set up as follows:

Column Information

Ref. Reference information

EPX X Value of Endpoint

EPY Y Value of Endpoint

Angle/Rad Line Angle or Arc Radius

Length Line Length or Chamfer Length

LP/CPX X Value of Line Point or Center point

LP/CPY Y Value of Line Point or Center point

The Geometry Expert also has a prompt line at the bottom. This prompt line will tell you when you have a fully defined line, an invalid feature, or when you need to add more information.

First, you will create a vertical line that passes thru X20. Make sure the feature type shows the Line icon. Enter 90 in the angle box and enter 20 in the LP/CPX box. Notice the prompt line at the bottom of the Geometry Expert tells you that you have a fully defined line. Your spreadsheet should look like the following image.

Press enter. A vertical line will appear.

A new row will be added to the spreadsheet. Enter the values shown for line 2. This will create a horizontal line thru Y80.

Press enter. You will notice a blue connector dot appears on the screen.

Enter the values shown for line 3.

Press enter. The horizontal line you created passing thru Y80 will be trimmed.

Enter the values in line 4. This will create a horizontal line thru Y60.

Press enter. Notice the lines trim again. The blue lines represent geometry that is fully connected.

Enter the values shown in line 5. This will create a vertical line thru X80.

Press enter.

Next, you will create a horizontal line from the current location that has an endpoint of X65 Y80. You will use this endpoint to start a clockwise arc in the next step.

Press enter.

Now you will begin the arc. Click and hold the mouse on the Feature Type icon.

Select the Clockwise Arc icon from the feature types and enter 30 for the radius. Your screen should look like the image below.

Press enter. You will not see the arc yet because it is dependent on the next line.

The next line will be a horizontal line that passes thru Y20.

Press enter. You will now see the arc and the line.

The next line will be a vertical line that will pass thru X50.

Press enter.

The next line will be a horizontal line that passes thru Y40.

Press enter.

The next line will be a vertical line that passes thru X40.

Press enter.

The next line will be a horizontal line thru Y20.

Press enter.

You are now ready to connect the last line drawn to the first line drawn. Select the Connect icon accessed from the Feature Type icon.

Press enter.

You will now add some fillets. This can be done inside the Geometry Expert, but you will use the CAD tool instead because it allows you to do multiple fillets at once. With Geometry Expert you must enter a line for each fillet.

Exit the Geometry Expert by clicking on the X located at the upper-right hand corner of the spreadsheet.

Hold down the control key and select the 4 corner points as shown:

Select the Chamfer icon from the Geometry Palette.

The Fillet-Chamfer Sub-Palette will appear. Select the radius icon as shown and enter 2 for the radius value. Select the Circle icon in the upper-right corner of this box.

The fillets are now added.

This completes the exercise. Save the file. Choose File-Save from the Main Menu,