How to Detect Identical and Mirrored Parts in AutoCAD

A cabinet run repeats itself. The same shelf appears eleven times, the same side panel appears in every unit, and the left and right sides of a carcass are mirror images with the hinge holes on opposite faces. Processing each of those separately is slow — and treating them as identical when they are actually mirrored is worse.

Why size alone is not enough

Two parts can measure exactly the same and still not be interchangeable. A cabinet side drilled for hinges on the left is not the same part as one drilled on the right, even though a tape measure says otherwise. Group them by dimensions alone and you will cut two identical panels, then discover at assembly that one of them is drilled on the wrong face.

That is why matching has to look at the hole pattern as well as the dimensions. Same size, same drilling — identical. Same size, mirrored drilling — a left–right pair.

Identical parts

The IDENTICAL detection compares parts on both criteria. When it is switched on, matching parts are grouped and the quantity is filled in for you: you set the description and banding once, and it applies to all eleven shelves.

When it is switched off, every part is processed individually — useful when the parts happen to match but you want to name or treat them differently.

Mirror pairs

The MIRRORPAIR detection looks for the left–right relationship: cabinet side panels, door pairs and other symmetrical components. It uses the same two criteria, so a pair is only recognised when the geometry really is mirrored, drilling included.

Recognising pairs matters beyond the cutting list. A mirrored pair shares one CNC program run on opposite faces, which means fewer programs to manage and fewer chances to send the wrong file to the machine.

What you end up with

• Repeated parts grouped, with quantities counted for you
• Left–right pairs recognised instead of being flattened into duplicates
• Matching based on drilling as well as size, so mirrored parts are not confused
• Fewer entries to fill in, and fewer CNC programs to manage

Both detections run inside the CABINET batch process, so they apply to a whole carcass in one pass. On the Enterprise plan they can also be run on their own, against any selection.