Composite Position Tolerance Zone Parameters

[[le...]]

Good morning. Is anyone able to explain what the "Additional tolerance zone direction" parameter does. I have the Circular type picked and the direction set as XY, but it's forcing me to select an option here and I'm not sure what it does. I've read through the help file and I can't find anything that mentions this parameter. Picture is attached.

[[Ch...]]

This parameter is needed when you cannot estimate all needed information about the location of the tolerance zone from the nominal fitting element. Then you have to specify it manually. 

In your case I would assume that your pattern consists of circle delivers only one point per element. Then for these element it is unsure how a cylindrical tolerance zone is orientated. Maybe it should align to the datum system or maybe not. Therefore you have to specify the nominal direction. 

 

Hope this helps

Christoph Schult