Why do I get "Model thickness exceeds material thickness" when I calculate a toolpath?

What the message means

The combined 3D model in the job is taller than the material Thickness in your job setup, so there is no way to fit it inside the block. The number the software checks is Model Thickness on the Material Setup form. The documentation defines it as the thickness of the composite model built from all currently visible components. That is why the figure can be larger than any single piece: components that add together stack their heights.

Usual causes, most likely first:

1. Two or more components set to add together, so their heights sum.
2. An imported model that came in taller than expected (often a units mix-up on import).
3. Extra base height or a leftover component you forgot was visible.
4. The job Thickness was typed smaller than the real board.

How to fix it

1. On the Toolpaths tab, click Set... in the Material Setup section.
2. Read Model Thickness and compare it with the material Thickness.
3. Pick the fix that matches your intent:

• The model should be shallower: click the Set button beside Scale Model Height and reduce the Z height of the composite model.
• The board really is thicker: correct Thickness in Job Setup.
• A stray component is inflating the height: untick it in the Component Tree, or hide components one at a time until Model Thickness drops, then fix that piece.

4. Back in Material Setup, set Gap Above Model or Gap Below Model to place the model in the block. Double-clicking the slider marks snaps the model to top, center or bottom.
5. Recalculate the toolpath.

How to confirm it is fixed

Model Thickness is equal to or less than Thickness, the toolpath calculates without the message, and the preview shows the model fully inside the block.

Pro tips

• Scaling height changes the whole composite model, not one component. To flatten just one piece, change that component's own height instead.
• In a two-sided job, the gaps apply to the complete model from both sides combined.
• For models that sink below the surface, see the entries on the Modeling Plane and the Zero Plane.