Belanger said:
CheckerHater said:
Y14.5 allows for total runout apply to conical surface.
It does?
I realize this is a topic of much debate and little consensus, but I suppose I'll take the bait.
ASME Y14.5-2009 Fig. 9.1 shows a conical surface as one of the three example "surfaces constructed around the datum axis". Para. 9.4.2.1 makes no attempt to restrict the application of total runout to some subset of those surfaces. I certainly don't have answers to the inevitable questions about angle tolerances, but I have no objection to a total runout tolerance applied to a conical surface with a basic angle.
I think section 9 generally does a poor job of actually defining the runout tolerances, and would benefit from a rewrite that doesn't involve inspection methods.
Also, instead of adding new terminology and symbology for dynamic profile in the next version, I think it would make more sense to just expand the definition of total runout. Something along the lines of the following perhaps:
The boundaries of the total runout tolerance zone are equally distributed about a geometric shape which is a variable facsimile (a "normal expansion or contraction") of the true profile. The toleranced surface must lie within this zone.
Any thoughts on the relative merits of this approach? Based on the 24 November 2015 draft it's clear the committee doesn't agree with me, but as far as I can tell they are just adding unnecessary complication.
pylfrm