[Cl...] Posted October 27, 2021 Share Posted October 27, 2021 I have a surface profile callout 6x equally spaced (60° circular pattern rotating around X) for each of the six features I'm recalling 3d curves into Free Form Surfaces. Since These profiles are not called back to any Datum, should I create an alignment for each one and allow rotation around X? Link to comment Share on other sites More sharing options...
[Ro...] Posted October 27, 2021 Share Posted October 27, 2021 Hi Clarke, If it's a 6x pattern it needs to be best fit and evaluated as a group. You can evaluate each profile separately, but they need to be evaluated in the same best fit alignment. If you're using curves, you could create a best fit alignment from curves, and select that in your profile evaluation of each curve/surface. Link to comment Share on other sites More sharing options...
[Cl...] Posted October 27, 2021 Author Share Posted October 27, 2021 Thanks Robert. Since these aren't called back to any datum, what about allowing rotation around X? Link to comment Share on other sites More sharing options...
[Ja...] Posted October 27, 2021 Share Posted October 27, 2021 You should allow for all degrees of freedom not just rotation in X. Link to comment Share on other sites More sharing options...
[Cl...] Posted October 27, 2021 Author Share Posted October 27, 2021 Just for rotation not translation, correct? Link to comment Share on other sites More sharing options...
[Ke...] Posted October 27, 2021 Share Posted October 27, 2021 Please sign in to view this quote. If the profile is not called out to any datum, then shouldn't all rotations & translations be free? If there isn't another profile/location callout that evaluates the features when constrained to a datum, then the engineer may not have completely understood what they were putting on the print(?) Is this for an internal customer, or an external customer? Link to comment Share on other sites More sharing options...
[Cl...] Posted October 27, 2021 Author Share Posted October 27, 2021 External (Medical device) Only a customer spec is called out on the print. Link to comment Share on other sites More sharing options...
[Cl...] Posted October 27, 2021 Author Share Posted October 27, 2021 I just found the spec. It is ISO 2768-2 Class Medium K. Calypso does not have as an option this spec. Link to comment Share on other sites More sharing options...
[Ro...] Posted October 27, 2021 Share Posted October 27, 2021 That ISO spec is a general tolerance document to control geometric tolerances on untoleranced features. It shouldn't apply to your profile if it's already toleranced in the drawing. If the profile doesn't have a tolerance then you would use that spec. Link to comment Share on other sites More sharing options...
[Ja...] Posted October 27, 2021 Share Posted October 27, 2021 If no datums are specified on profile callout, it just means that you are best fitting the nominal surface to the actual surface without any constraints. Meaning your nominal surface should be free to rotate and translate in all axes so as to achieve that bestfit with lowest possible deviation. Link to comment Share on other sites More sharing options...
[Ch...] Posted October 27, 2021 Share Posted October 27, 2021 Since these are 6x pattern, you may want to use Geometry Best Fit, from Resources, Utilities menu, instead and allow rotation around the proper axis. Similar to a pattern of holes and SIM REQTs : if you rotate individually, Calypso might rotate a lot to fit of your features, but in assembly - depending on the function, they wont be able to rotate this much individually, etc. Then in your Profile characteristic - you would choose your Geometry Best Fit for all 6. Good luck, and happy measuring ! Link to comment Share on other sites More sharing options...
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