Color analysis at the IPW

In this video, Heinrich Flaum shows you how to use color mapping in Siemens NX to check your part and quickly spot any deviations.

The part is fully programmed, and all operations are in place. It is set up on the GROB machine. To start the NC code-based machine simulation, simply click Simulate Machine at the top. Once the postprocessor has finished generating the NC code, you can start the simulation by clicking Play. After the machining process is complete, you can review the result and check if everything was executed as intended.

Let’s turn to the initial challenge: the goal is to determine where too much material was removed, where excess material remains, and which areas of the part lie within tolerance. To do this, click on Analyze at the top. The system then overlays the nominal model from design with the actual machined part. Based on the color scale, dimensional differences between nominal and actual geometry become visible. These are the default settings in Siemens NX. For a clearer evaluation, start by reducing the number of ranges to three, so that only three colors are shown. For example, you can assign the following colors: Gray for excess material, Green for areas close to nominal, and Red for gouging or material violations. The next step is to adjust the settings under Divisions and the Min/Max limits.

After changing the min-max limits and deviations from Automatic to User-Defined, the following values are set:

Limits for 3 colours:

• Upper limit: 800 mm (very high maximum value)
• Tolerance range plus: 0.2 mm
• Tolerance range minus: -0.2 mm
• Lower limit: -800 mm

Colour assignment:

• Grey: Oversize > 0.2 mm to 800 mm
• Green: In-tolerance range between -0.2 mm and +0.2 mm
• Red: Part infringement < -0.2 mm to -800 mm

Click "Apply" to display the color-mapped model. For sharper contrast, switch the display mode to Sharp Edges instead of Soft Edges. You can click directly on part surfaces to read the exact dimensional deviations, for example:

• 2 mm oversize → grey area
• 0 mm difference → green area
• 0.4 mm undersize → red area (e.g. edge break due to unchanged drilling)

To display additional values, you can increase the number of color ranges, for example (optional):

• 800 mm to 1 mm: Blue 
• 1 mm to 0.2 mm: Green
• -0.2 mm to -800 mm: Red
• Anything above 1 mm: Gray

This allows for a more detailed visualization of dimensional deviations.