Geometric Tolerancing Applied to Floating Pin

[thugline]

I've recently run into a situation where a geometric tolerance is applied to a feature that is not fixed.

For the sake of simplicity, imagine a floating pin bushing (such as the one shown in the attachment) is pressed into a plate. The bottom of the plate is designated datum feature A. A perpendicularity tolerance is then applied to the pin (which is free to float) with respect to datum A.

How would one inspect this feature? Is this even legal? The drawing is supposedly in accordance with ASME Y14.5-2009.

 

[3DDave]

If the pin extends on one side and the datum feature is on the other side, that will almost certainly require s CMM.

Is the reference at Maximum Material Condition or Regardless of Feature Size?

The only decision is whether that perpendicularity tolerance needs to apply at all positions or if finding a single compliant position is enough.

 

[thugline]

@ 3DDave:

Tolerance on the pin is applied at RFS and CMM will be used for inspection.

You nailed it with your last statement. Without any additional instruction on the drawing, it seems open to interpretation on which position(s) the pin must be compliant. I would assume it'd be the latter interpretation (all positions must be compliant) unless otherwise specified.

The pin is allowed to float, but there is also play in the pin within the slot. If all positions must be compliant how can one be sure that all positions were measured?

 

[Burunduk]

Looks like the kind of things that should have been controlled on the detail level, correspondingly to the assembly  requirements.

 

[drawoh]

thugline,

Read up on datums. ASME[ ]Y14.5 addresses the issue of flexible parts.

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JHG