If a Blueprint calls for ASME Y14.5 wouldn't this be the standard rules apply. How would I know if and when to apply ISO? I have yet to see anything on a blueprint stating this. The reason I bring this up is for the good old Profile callout. Before I make an argument, I want to cover all my resources. Customer already claims in an email that PC-DMIS is not capable of doing this. I and everyone on here already that's horse_S_H_I_T. But its Friday and I'm ready to P_I_S_S someone off
Equally disposed bilateral profile of .020 fully constrained to datums. This is basically a straightwoward +/-.010 dimension. Right?
So, you measure it in pc-dmis and the deviations range from +.0095 to + 0099. pcdmis reports the measured profile as .0099, not even using up half the profile tolerance. If you report this result in something like an FAI report, it's downtight misleading (maybe even fraudulent). BUT, if you double that worst value you report .0198 for the profile result. This represents the true nature of the result - on the ragged edge of the tolerance.
Of COURSE the worst deviation should be doubled. And of COURSE this is my opinion. There are no specific instructions for how to do it. And frankly, the doubling approach falls apart when dealing with an unequal bilateral profile. So it isn't a universal solution.
The bottom line is that pc-dmis fails bad parts and passes good parts. And that's probably what you should tell your customer.
I've made peace with the pcdmis method. But it isn't a matter of ASME vs ISO. It's just their way.
Your example is not a bad part, regardless of how it's reported. So, where's the fraud? Nobody that I've seen has said "PC-DMIS has it right", so let's dispose of that strawman.
It is a matter of ISO vs ASME. ASME does not specify how TO report, but it does specify how NOT to report. Very clearly.
Doubling doesn't tell you anything more than just reporting the Max and Min deviation do, plus Max/MIn works in ALL cases. Win-Win.
Your example is not a bad part, regardless of how it's reported. So, where's the fraud? Nobody that I've seen has said "PC-DMIS has it right", so let's dispose of that strawman.
It is a matter of ISO vs ASME. ASME does not specify how TO report, but it does specify how NOT to report. Very clearly.
Doubling doesn't tell you anything more than just reporting the Max and Min deviation do, plus Max/MIn works in ALL cases. Win-Win.
