MMC for profile of a surface

[dcoss]

I'm trying to use legacy dimensioning to apply MMC for a couple datums for profile of a surface (both form and location). There doesn't seem to be any of the buttons to select MMC, LMC, or RFS on here. Is there any way to do this with legacy?

[bfire85]

Can't do it in legacy. You can in Xact. Question: Do you REALLY need it?

[Matthew D. Hoedeman]

Can't do it in legacy. You can in Xact. Question: Do you REALLY need it?

MMB, not MMC, for the datums.

[bfire85]

Yes. Correct. Too early in the morning when I posted to play the grammar (your, you're) game. Lol.

[Trevor McLaughlin]

Disable Legacy Dimensions and use Xact Measure for Surface Profile. You can then use a modifier on your datums.

[Sora5]

Not only profile, you should never use MMB in legacy. It's wrong and just add in values as additional tolerance instead of calculating datum shift. Use Xact measure if you need to use material conditions on datums. This has been a giant pit trap for new users to fall in that has never been filled.

[dcoss]

Disable Legacy Dimensions and use Xact Measure for Surface Profile. You can then use a modifier on your datums.

In the Xact measure attached pic, are you supposed to put the size of the datum in the modifier info or leave it blank? I'm confused.

[Trevor McLaughlin]

No, I would leave that field alone. It's meant for defining a specific MMB size, if the implied boundary is not clear. If you open the Nominals tab of your dimension dialog, you will see your datum feature in a list where you can define both the nominal size and the tolerance. The amount your measured datum feature deviates from nominal will determine the amount of datum shift.

[Trevor McLaughlin]

Here's what the Help files say on the subject of defining a specific boundary size:

Stating a Specific Boundary
If you want to define a specific boundary, perhaps because the implied boundary is not clear, you can use the Feature Control Frame Editor to explicitly state the boundary by enclosing it within brackets immediately following the applicable datum feature reference and any modifier following that datum feature reference. This value represents the size of the material boundary. PC-DMIS uses it to calculate the bonus on the datum feature, disregarding any preceding position or orientation tolerances on the datum feature: