How to calculate MMC exactly

[[Pa...]]

I'm new to GDT within the past year. My understanding is that CALYPSO sometimes refuses to calculate MMC/MMB on TP callouts because the calculation is too complex. If this is correct - would it be possible/reasonable to attempt to write a Python script to do these calculations? How would that calculation be done? Any info/resources would be helpful.

[[SH...]]

I think there will not be any issue with MMC for any features, problem will be with MMB, yes calypso will not support a MMB for all features. Problem might be in the complexity in the algorithm,Calypso will not support three dimensional MMB.One of the ideologies calypso follows that should not give a good report to a bad part.

[[Ro...]]

I think the "Its too complex" statement sounds like a bunch of PCD hogwash.
PCD has in recent years started calculating profiles in the same way that Calypso has been calculating for over 10 years (deviation = larger of min & max x2 instead of min + max). PCD also likes to give bonus on just about any feature weather it be primary or secondary or tertiary, it all gets bonus.
Calypso often will not give bonus on a cylinder because what is the diameter of a cylinder? where is it being measured? a 3D feature can be wildly different depending on where it is measured, in taking your GD&T classes you know the diagram of cylinder (cylindricity) and it's possible form errors.
So maybe the statement could be better explained by saying Calypso doesn't just give out bonus unless you program it correctly, and its warranted by the standard.

If you want a better chance of getting your bonus you need to boil your 3d features down to 2d features. for the diameter of a cylinder, create a circle from the cylinder and its plane because a circle is more likely to pass the bonus threshold. this also works for the cylinder location, a point or circle at a given height is better than a random cylinder x or y.

[[Ke...]]

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It seems like for this method, you would still need to confirm the cylinder at different heights; possibly by projecting the circles (at top or bottom of the cylinder) to the correct height for the 2D evaluation(?)