Flatness question

[[Ja...]]

In the picture below, how would i report the |Flatness|.001/1.00 x 1.00|?

In the second pic, you can see the scanning paths I used.

[[Ma...]]

If you don't have "Flatness ref." then i affraid it will be hard.

I think it is in 2018. On newer versions it's added even for curves

[[Ja...]]

What's the difference between "Reference plane in each zone" and "Reference overall plane" 

[[Ma...]]

Citing manual

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[[Ja...]]

How do you decide which option to use?

[[Ma...]]

I don't know which one to use, but i got to an explanation:

• Refference plane in each zone:
  • You evaluate each zone independently - each zone has it's own tilt ignoring others
• Refference overall plane:
  • It's determined one common plane and then each zone is evaluating only MIN/MAX point inside it's zone ( no tilt per zone )

[[Ri...]]

Your FCF appears to want "Reference plane in each zone" as shown by "1.00x1.00".

Reference Plane in Each Zone = .001 per 1.00 × 1.00

• Any local 1.00" × 1.00" inspection area must fit within two parallel planes separated by 0.001.
• This could also mean sometimes you can't construct a 1.00x1.00 zone, maybe you get a .75x1.00 zone, etc. Each zone as closely related to 1.00x1.00 is treated the same.

I don't recall having to use the other method. But it seems like each 1.00x1.00 segment must be within ±.0005 within the entire surface used, not just per segment.

Another note:

The note "A 2 SURFACES" suggests the flatness may apply to two surfaces considered together. You should get clarification on that.

This may force you to use the latter description which I believe is stricter than each segment individually.

[[Ja...]]

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There is a small (.060 deep x 1.25" long) notch that separates the two planes of Datum A.  We machine the entire surface of Datum A with a shell mill prior to any other machining, so I am not too concerned with the "2 SURFACES" being within tolerance.

 

[[Ja...]]

thanks for the help, Richard and Martin.