MMC from datum features does not add to the tolerance, it provides datum shift the was a hard gage with stab pins allows the part to "wiggle" on the datum locator pins and I'm thinking it will only use the datum shift if it is needed
you only get the feature and 1 datum bonus with legacy dimensioning. the new GD&T dimensioning applies all of them i believe. pick your poison...
kinda looks like you might have encountered a little bug possibly, tho after looking at it, should get 0.005 plus the teritary datum bonus of 0.0022 which should be 0.0072 in total.
Check your recalled alignment matches before your legacy dimension to what youve called out as D1,D2,D3
Do you by chance have a 2D best fit alignment in place before the legacy dimension? Bonus tolerance wouldn't be applied unless the TP was outside your limit which it isn't. The datum shift, I don't believe, would be able to be applied if your current alignment for that dimension constrains all degrees of freedom.
Now take with a grain of salt I could be way off... I'm pretty dumb for a programmer.
dcoss. The following PC-DMIS help page explains how legacy position works. The behaviour differs depending on what combination of "Use Datums" and "Fit to Datums" settings you select:
PC-DMIS Help Center - 2023.2 (hexagonmi.com)
1. The "Bonus" columns in the D1,2,3 lines don't actually show a bonus, but an allowable datum shift. There is a difference between those things.
2. The only true bonus is for the tolerated element itself. In this case it's an OD, the MMC bonus is Upper Limit Diameter (MMC of an OD) minus Actual Diameter, giving 0,0050.
3. Your actual deviation is 0,0035. No need for the bonus to kick in, let alone the datum shift. That will only happen when your actual is OOT, so your tube position made it in tolerance all on its own. Congratulations!
