NX Setting Machine Collision Check with an Inactive Spindle

There may be a requirement in manufacturing processes where spindle rotation is deactivated. When the spindle is inactive, the standard collision checks, Tool/IPW and Tool/Part are not used. This could be a problem for users and fail in identifying collisions within the simulation, potentially resulting in on-machine incidents. 

In the example provided a simple milling toolpath is shown which initially has the spindle rotating and material is correctly removed in the simulation. 

The 'Spindle Off' user defined event (UDE) is added which will add an M5 code to the NC output, deactivating the spindle rotation.  

Running the simulation again shows that the spindle rotation is inactive and the material is not removed, however, this would generate a clear collision on the machine. Tool/IPW and Tool/Part collision checks are enabled but as the spindle is inactive these checks are not used.

In order to ensure collisions are checked in this scenario, machine collisions and collision pairs must be specified. 

To achieve this, open the Simulation Settings dialog and enable 'Check for Collision' under the Machine Collisions section. 

It is then possible to 'Specify Collision Pairs. In this dialog, set the tool and workpiece as a pair. 

Once defined and running the simulation again shows that the collisions are identified and a Collision Violation warning appears. Now the user is aware of the potential risk associated with this operation.