Profile tolerance datum??? 1

[KGRZEBIEN1]

DO YOU NEED TO USE A DATUM REF WITH PROFILE TO A SURFACE CALLOUT?
or can you allow the dimensional values allown dictate the shape.
(the size of the surface)

I am concerned about the shape of the O.D. of a cylinder after coating.

 

[powerhound]

The direct answer to whether or not you NEED a datum with profile of a surface is "no" but it always depends on what you're trying to do. In your case it sounds like cylindricity may be a better choice if you want to allow the OD to be able to fluctuate within a size tolerance. Maybe attaching a drawing may help someone else on here give a more specific answer.

Powerhound, GDTP S-0731
Engineering Technician
Inventor 2010
Mastercam X6
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II

 

[KGRZEBIEN1]

Winner!! thanks powerhound. that's exactly what I need.