Support for a 2 point min max tolerance

[GitHubDaveSmith]

This would be used to report a diameter characteristic as a 2 point min max evaluation. Currently a custom attribute is used within a DiameterCharacteristicDefinition element.

[daniel-campbell]

Is this for an ISO GPS part? I thought that this was possible for ISO GPS -- I don't remember the details, but I thought that the necessary modifiers were added to QIF to handle this.

But it brings up another point: Y14.5 asks for 2 types of size to be evaluated for a size tolerance - mating envelope and actual local size. It should be possible to specify both results in QIF for a size tolerance, but I'm not sure how this works. This is a topic for investigation.

[GitHubDaveSmith]

You are correct, QIF does provide support but it appears to be specifically tailored towards the ISO standard. It would be useful if a solution that is closer harmonised to the ASME standard would be helpful.

[larry-bergquist]

Actual local size has been a topic of debate for a long time. I think there may be clarification in the future.
For now, I recommend referencing ASME Y14.5.1-2019 (supports Y14.5-2009) para. numbers and titles listed below:
2.3.2 Variation of Size
2.3.2.1 MMC Limit, Where Rule #1 of Y14.5 Applies
2.3.2.2 MMC Limit, Where Rule #1 of Y14.5 Does Not Apply
2.3.3 Actual Local Size Limits
2.3.3.1 Establishing the Local Size Spine
2.3.3.2 Evaluation of Actual Local Size (Opposed Points)
2.3.3.3 Evaluation of Actual Local Size (Circular Elements)