Simulate¶

In one sentence: Animate the toolpath and show the material removed from the stock as the virtual tool moves through each operation.

Overview¶

Workbench: CAM
Menu: CAM → Simulators
Commands: CAM_SimulatorGL (GL Simulator), CAM_Simulator (legacy)
Shortcut: none

Two simulators are available: the GL Simulator (default, OpenGL-based, real-time) and the legacy Simulator (Python-based, slower). Both animate the toolpath and show the resulting machined shape.

Intuition¶

Simulation lets you visually verify that the toolpath cuts the right geometry before sending G-code to the machine. It catches crashes (tool hitting the fixture), gouges (cutting into unintended geometry), and missed material — all without risking a broken tool or damaged workpiece.

Always simulate before post-processing.

When to use it¶

Before post-processing to verify the complete toolpath.
After adding dress-ups to check their effect.
When debugging an unexpected operation result.

GL Simulator (default)¶

The GL Simulator renders material removal in real time using OpenGL. The stock starts as a solid block and the tool is animated, removing material as it moves.

Control	Action
Play / Pause	Start/stop animation
Speed slider	Playback speed multiplier
Step	Advance one G-code line
Show tool	Toggle tool mesh visibility

Legacy Simulator¶

The older Python-based simulator is slower but works without hardware OpenGL. It shows the resulting mesh after all operations are applied rather than animating in real time.

Common mistakes and pitfalls¶

Simulation looks correct but machine crashes

Simulation uses the CAM model geometry. If your actual setup (fixture, clamps, table surface) is not modelled in FreeCAD, simulation cannot detect collisions with those items. Always leave adequate clearance.