I am trying to measure Position (TP) of several holes/slots that are on a part with no Perpendicular Datum Scheme. With the compound angles of the surfaces and rotations, I am not getting accurate results. I can see that when I measure individual points around a slot for example and they are good. Would it be best to create another alignment, rotated (all 3 axis) so that I would have a parallel/perpendicular feature to Datums? If so, how do you know what angles to rotate to?
Possiblity 1: I'm making an assumption here that you are using XActMeasure and getting wild results because the datums are not perpindicular to each other. I don't know if GeoTol handles this better, coding this would be a miserable endeavor for the dev team, so I'm not throwing stones here.
Prior to PC-DMIS 2020 R2, with the XactMeasure command, datum reference frames were handled rather like a PC-DMIS alignment, with a level feature, a rotate feature, and one or more origin features. All of these features you selected from the datum features. Starting with version 2020 R2, the geometric tolerance command does not use any alignment concepts for datum reference frames. Instead, it uses gage concepts for the datum reference frames. This enables support for more unusual datum reference frames that cannot be represented by the level-rotate-origin framework.
Comparison to Past Practice
Starting in PC-DMIS 2020 R2, the geometric tolerance command analyzes the datum reference frame in terms of invariance classes. This enables correct handling of unusual datum reference frames where the vectors are not square to each other. For example, a primary datum plane with a secondary datum plane at a 30 degree angle to the primary has a prismatic invariance class. Prior to this version, PC-DMIS did not fully support these unusual datum reference frames.
Possiblity 1: I'm making an assumption here that you are using XActMeasure and getting wild results because the datums are not perpindicular to each other. I don't know if GeoTol handles this better, coding this would be a miserable endeavor for the dev team, so I'm not throwing stones here.
Prior to PC-DMIS 2020 R2, with the XactMeasure command, datum reference frames were handled rather like a PC-DMIS alignment, with a level feature, a rotate feature, and one or more origin features. All of these features you selected from the datum features. Starting with version 2020 R2, the geometric tolerance command does not use any alignment concepts for datum reference frames. Instead, it uses gage concepts for the datum reference frames. This enables support for more unusual datum reference frames that cannot be represented by the level-rotate-origin framework.
Comparison to Past Practice
Starting in PC-DMIS 2020 R2, the geometric tolerance command analyzes the datum reference frame in terms of invariance classes. This enables correct handling of unusual datum reference frames where the vectors are not square to each other. For example, a primary datum plane with a secondary datum plane at a 30 degree angle to the primary has a prismatic invariance class. Prior to this version, PC-DMIS did not fully support these unusual datum reference frames.
