Virtual Condition Check at RFS 3

[dthom0425]

Hello all-

I am aware of how to perform virtual condition checks for MMC and LMC but I am wondering how does one verify (what is the math?) that the RFS true position applied to a hole will work in a mating condition.

Example:

C'sink with .150" thru hole @ (dia) True position .010" RFS.
mates to
#6 thread (.138) @ (dia) True position .028" RFS

How would you verify through math that your true position tolerancing is OK at RFS?

Thanks

 

[Sem_D220]

dthom0425, here is how I would do the check:
Worst case boundary for the hole: minimum minor diameter of the hole thread (the MMC condition) minus .010".

Worst case boundary of the threaded pin: maximum major diameter of the pin ( the MMC condition) plus .028".

Just make sure that the worst case boundary of the hole is larger than the worst case boundary of the pin. This could work if the position tolerance locates both the threaded pin and the hole coaxially to mating diameters on both parts which fit closely enough.

 

[Sem_D220]

One more thing:
The fact that the position is specified RFS, only means that you don't get any bonus tolerances for producing the parts in other sizes than MMC. It doesn't affect the math behind the calculation for the worst case condition for mating.