During toolpath simulation spindles and tool holders can be displayed. This allows you visualize the how the spindle and holders interact with the part and to detect any interference between the holders or spindle and the part.
Overview of spindles and tool holders
Displaying spindles and tool holders during simulation
Setting the length of tool extending past the holder
Detecting of gouging with tool holders and spindles
Spindles and tool holders dialog box
Creating or modifying tool holders
Creating or modifying spindles