[To...] Posted November 16, 2023 Share Posted November 16, 2023 I am measuring a parabola with a Surface Profile with no Datum Reference Frame. However, it appears that all of my data points are on the plus side of the surface. Wouldn't some points be on the minus side?Profile_No DRF.JPG Link to comment Share on other sites More sharing options...
[Ri...] Posted November 17, 2023 Share Posted November 17, 2023 Looking at your points map, they appear to be of unequal height. Assuming you programed from an alignment, couldn't they be all positive yet have the unequal height distribution, showing a stock on condition? If the part was at nominal, you could potentially have plus/minus data. Link to comment Share on other sites More sharing options...
[To...] Posted November 20, 2023 Author Share Posted November 20, 2023 Please sign in to view this quote. Doesn't "No Datum Reference Frame" exclude any connection to an alignment that might be used? Link to comment Share on other sites More sharing options...
[Ri...] Posted November 20, 2023 Share Posted November 20, 2023 Please sign in to view this quote. I believe its compared back to the model. I probably should have said "programmed from a Model". Link to comment Share on other sites More sharing options...
[To...] Posted November 20, 2023 Author Share Posted November 20, 2023 Please sign in to view this quote. I'm not so sure but that's why I asked the question. Link to comment Share on other sites More sharing options...
[Ma...] Posted November 20, 2023 Share Posted November 20, 2023 If programmed from CAD, to fix the gaps, select "Actual to Nominal" from the "Nominal Definition" drop-down menu. Also, ensure that there is no offset in Evaluation. Additionally, perform a 3D Best Fit alignment from the feature being measured and use it as the Datum Reference in the profile. Link to comment Share on other sites More sharing options...
[To...] Posted November 20, 2023 Author Share Posted November 20, 2023 Please sign in to view this quote. This is a Free Form Surface. Link to comment Share on other sites More sharing options...
[Ja...] Posted November 20, 2023 Share Posted November 20, 2023 With no datum reference selected, the profile should have max and min points equally distributed on either side of the surface unless the surface starts having geometrically opposite vector points. But your freeform surface does not have geometrically opposite vectors so maybe this is a software bug that all your points are on one side. Try doing geometry best fit alignment with all constraints selected and use that as alignment for the characteristics. That should work for now until the bug is fixed. Link to comment Share on other sites More sharing options...
[To...] Posted November 22, 2023 Author Share Posted November 22, 2023 Please sign in to view this quote. That's what I was thinking. However, since the shape is a parabola, technically, there are some ever-so-slightly opposing points. Not at Calypso, can you do a GBF on a freeform surface? Link to comment Share on other sites More sharing options...
[Ma...] Posted November 23, 2023 Share Posted November 23, 2023 What can you do if you have a model - use 3D curves if possible. Otherwise try playing with RFS FF Link to comment Share on other sites More sharing options...
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