Profile of plane without Datums

[[Jo...]]

Hi see attached. In regards to the yellow highlighted profile callout sans any constraints, how would you populate the profile characteristic in Calypso? This is just a wide open plane. Not offset or coplanar. Let's just call it Plane_1.

Thanks!

[[To...]]

Starting in Calypso 2023, you have the option of using a GD&T Engine_BETA, which I'm pretty sure allows you to select the plane and leave the datum structure empty.

[[Jo...]]

So with older versions (2018 6.6 in my case), do you populate the primary/secondary/ tertiary with just Plane_1? It's the only way it gives you a result. Is it correct though?

[[To...]]

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In my opinion, this needs to be a Freeform Surface feature, which can be used in the Profile with "No Datum Reference" selected.  However, there might be an alternate unpublished solution, like a Flatness, though I don't get the same results when I have tested it.  Likely due to evaluation settings.

 

UPDATE:  In the GD&T Engine_BETA, Flatness and Profile with no datum features selected, the results were the same. (to 7 places in inches)

Edited December 12, 2024

[[Mi...]]

*Assuming ASME, not sure if ISO is different*

 

Form only Profile of a Plane IS flatness ( or Roundness, or Cylindricity) from a mathematic point of view, the difference is more subtle. Profile can apply to separated surfaces and evaluate them as one, Flatness, technically must be 1 continuous surface. So the question then is, why does your drawing have both with different tolerances?

 

https://www.tes-tec.net/en/flatness-vs-profile-controls/

You CAN sometimes get 2018 to calculate profile like this but it throws errors so often.

*SAVE THE PROGRAM FIRST, THE ERROR IS OFTEN BAD ENOUIGH CTRL+Y WON"T SAVE YOU*

In your profile characteristic populate the toleranced feature and all the datums, set the evaluation setting for each one to "Minimum Feature". If it doesn't get mad at you, you'll get exactly the same result as Flatness...but you'll have the correct symbol in your report

Edited December 12, 2024

[[Ri...]]

As Michael stated, if you go the route of using the Plane as the Primary/Secondary/Tertiary, you need to switch the evaluation to Minimum Feature. 

 

You can verify your results by evaluating the Flatness - if they aren't the same, something is wrong or set different. 

 

[[Ri...]]

Here is the same measurement in the new GD&T engine. 

[[Ma...]]

I am not sure ( and until new year i won't be infront of Calypso ), but on 6.6 you can select "No refference" which will result as bestfit - but i have to say : with FF, not sure if basic features ( plane, cylinder ) can be used.

And i have tested this as someone mentioned - filled all three with same feature as measured feature - got different results.
Better to use general surface ( FF ) with no refference.

Edited December 12, 2024

[[Jo...]]

Yes when I see all the GD&T thrown at this non threatening looking plane, (i.e multiple flatness & profile callouts) I wonder what they're going for..

Thanks all

[[Ma...]]

Does anything change if the plane in question has a dimension to another feature / feature of size?