true position help

[[Jo...]]

I have a square part. Datum structure "Y" , "U" and "Z". Y being top, Z being right side and "U' being back side. This is how my base alignment is setup.YUZ. when I check true position using base alignment vs putting in each datum I get totally different answers. Which is correct?

[[Am...]]

Check your true position using the datums in order of how they are called out on the print.

[[Jo...]]

that what I was doing. But shouldn't be the same since my base alignment is the same as the call out? It shows the locations being totally different looking at the feature vs the true postion location on the print out.

[[Am...]]

When you are putting in the true position you have primary datum, secondary, tertiary and you can arrange them properly. In base alignment you are putting in the spatial and planar rotation. That might not match up to the way the datums are called out on the dimension.

[[Ri...]]

Calypso follows the Can-May-Must rule.

Most likely your Base Alignment isn't setup the same way as your DRF.

If this is a Square Block:

- Y would control Spatial Rotation, and Z origin (depends on orientation).
- U would control Planar Rotation and Y origin (depends on orientation).
- Z would control X origin (depends on orientation).

[[Jo...]]

Thanks Richard, it was the planer that was throwing it off.