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Collisions/Limits gibbscam

The items found in the Collisions/Limits section of the dialog provide control over how the system reports collision errors while rendering. Any combination of the alert methods may be used to inform the user when a collision occurs.

Please note that the Collision Checking option (found in the Render Control palette’s menu) must be activated for the system to check for collisions.

A collision in Machine Simulation occurs whenever any two objects contact each other during the simulation that are not supposed to touch. Objects in Machine Simulation include machine components and non-machine components. Machine components are objects in the machine assembly that are defined by Build Machine. Non-machine components are not in the machine assembly, but are created by Machine Simulation based on information in the GibbsCAM part file. These objects include tools, holders, fixtures, parts, and stocks. The active cutting tool and its holder always participate in collision detection when collision detection is activated. Other objects participate in collision detection based on their inclusion in collision component groups. Collision component groups are component groups with their collision setting turned on. See Component Groups for more information.

Non-machine objects are automatically included in component groups based on their logical attachment to an object in a component group. For example, a tool and tool holder are logically attached to a turret by virtue of their assignment to a particular toolgroup and tool position in the tool definition dialog in GibbsCAM. A part/stock is assigned to a spindle or chuck in the machine assembly because of the part body (P-body) that is defined in the machine model. When determining group membership, fixtures inherit goup attributes from the part body associated with the fixture’s spindle.

Machine simulation collisions are detected when collision detection is set on, and any of the following conditions occur:

The cutting portion of a tool contacts the part/stock while in rapid mode.
The non-cutting portion of a tool or holder contacts the part/stock while cutting.
Any object that is part of a collision component group contacts any object that is part of a different collision component group.
Any axis position exceeds the axis limit as defined in the machine assembly for any of the machine components with axis limits (min/max).

Alert Types

You may choose any or all of the various feedback methods that alert you to a collision. The Beep option provides an audible alert, Log To Display will output an error in the Clash Console log window and Stock Flash provides a visual alert to the error by flashing the rendered stock. Stop Animation will cause the rendering to stop when a collision is detected.


The Tolerance setting allows a different value for metric and inch parts. Any collision within the specified tolerance will generate a collision alert.


The Clash Console output showing a tool clashing with the stock and a fixture.

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