Calypso MMC

[[Ja...]]

 

I am trying to check a Perpendicularity and position using MMC. As I understand MMC, it allows extra tolerance when the diameter is larger than nominal size. In the example above the actual diameter is smaller than nominal yet the MMC position is almost .004 under the actual position. How is this possible, what have I done wrong?

[[Ma...]]

As replied in another thread - in this table where is (M) it's calculated statistical value just for SPC purposes - real value is without (M) but your tolerance is increased.

(M) value can be "ZERO" when you have allout as "0 (M)" because of formula ( can be found in forum ) - in that formula is final step a multiplying of base tolerance.

[[Pa...]]

Be careful.  Nominal size is never a factor in MMC / LMC.  Only maximum and minimum sizes matter.

First, I assume the FOS is an EXTERNAL cylinder.  If so, it goes like this:

If your external cylinder is at its very smallest size allowed by the tolerance, the design can tolerate greater deviations to position.  MMC gives a "bonus" tolerance calculated by subtracting the actual size from the maximum allowable size and adding that value directly to the position tolerance given in your FCF.

If your cylinder is an INTERNAL FOS:

If your internal cylinder is at its very largest size allowed by the tolerance, the design can tolerate greater deviations to position.  MMC gives a "bonus" tolerance calculated by subtracting the minimum allowable size from the actual size and adding that value directly to the position tolerance given in your FCF.

Looking at the two red lines in your report, the top one contains the value you need to report.  This is the position fully resolved including all bonus tolerance.  The second line is something that should default to excluded but doesn't.  It's a useless value to you.  Search the forums; there are ways to remove this line with a snippet of code in your report template.