Note: Inventor Link is available only on 64-bit systems, and it is not installed by default.
  
 
- At the Command prompt, enter 
	 AMOPTIONS. 
  
 
- Click the AM:Drawing tab. 
  
 
- Select Automatic Centerlines. 
  
 
- Choose Apply, and then click OK. Centerlines are displayed for any view you create from this point forward.