5. In the feature browser using the right-hand mouse button, select the Mirror command. This will bring up the Mirror Feature tool.

6. You must choose a face or a workplane to act as the mirroring plane. I would suggest using an appropriate workplane so that any future changes to the features of the original part don’t provoke a failure. The new mirrored feature will be previewed. If all is well, choose OK to create the feature.

7. You should now have a model with the original feature driven by the part and a mirrored feature driven by the original feature. Note the extra features that have appeared in the feature browser.

8. Now that the mirrored feature exists, the original feature must be hidden/removed. Suppressing the original feature does NOT work. Instead you have to create a new feature that, when subtracted from the model so far, removes just the original feature. To achieve this, unhide the original component and use it to make a new feature in the same way as you did to make the original feature, but this time check the Subtract material button.

9. This should leave just the mirrored feature visible. Both the mirrored feature (tool 1) and the subtractive feature (tool 2) are driven by the same part, so that both will reflect any changes to it.

10. Save the design with an appropriate name e.g., <original file name>_mirror.des.

Things to be Aware of

• New features added to the original part appear in the mirrored part, provided they don’t cross the mirror plane.
• You can add new features to the mirrored part, but they won’t appear in the original part.
• If you modify the original part, you must open and update the mirrored part before the change will be applied to it.
• When windowing or rotating the mirrored part, it will react as though the original part is still attached (which it indeed is).
• The file size of the mirrored part is usually smaller than that of the original part because it has fewer features.

Mike Nelson is an engineering designer at Cambridge Consultants. He can be reached by email at mike.nelson@cambridgeconsultants.com.