I am facing difficulties figuring out how pc-dmis is calculating bonus tolerance.
in the two attachments when circle was a measured feature bonus tolerance was 0.0022,
for the same feature when it's used as datum tolerance changed to 0.0062.
You have a .004 position specification on CIR_AK with respect to primary datum J.
When you bring up datum reference frame [J|CIR_AK(M)], the material modifier on the secondary datum is MMB, not MMC. The MMB size is the datum feature's MMC size plus any applicable geometric tolerance with respect to higher precedence datums. Legacy takes your bonus of .0022 and adds the .004 allowable variation between the secondary datum feature and the primary datum to yield a "bonus" of .0062.
For further clarification, refer to ASME Y14.5-2009 Para. 4.11.6.1 and Fig. 4-16.
Look up Rob Jensens white paper. TRUE POSITION- PC-DMIS 4.1 LEGACY DIMENSION MODE. I attached it but I am not promising anything.
Hey look. It worked.
Rob did all the DMIS training in MSP for a looong time and still does the user groups ( pre covid anyways ) . I had 3 or 4 courses with him over the years. He left that and took over GD&T / dimensional compliance ( please don't quote me title name ) for Hexagon. Really making sure the software was giving you the right numbers based on the GD&T. I believe he is the chairman on the Y14.5 math committee and he may actually be on the Y14.5 as well ? . If its GD&T or CMM related and it comes from Rob, take it and run with it .
