Wire surface profile call out confusion.

Hello all

I have a surface profile call out for 3 mm, the program uses 1.5 -1.5 and deviation 3.0 to check all those hits. My question is whether unilateral profile should be only about max min deviation about 3 mm?
Can I use 3 mm and -3 mm to check the hits M value and relays on deviation only?

Thank you

Attached Files

bfire85 over 1 year ago

Since you are using Legacy dimensioning on the profile, you will need to report our the MAX and MIN deviations, which are in the textual analysis. I do not see the arrow that the profile callout is pointing at to see if it is a bilateral or unilateral tolerance. Either way, you will not have a +/- 3 tolerance.

What is the standard on the print? ASME? 1994? 2009? 2018? ISO? This will affect how you report the profile.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
RobOntario over 1 year ago in reply to bfire85

Asme y14.5-2018.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
RobOntario over 1 year ago

The current issue is TOL 1.5 -TOL 1.5 DEV1.506 still pass which will fail when Stepahead deals with multi part reports. And DEV should pass unless it is over 3.0
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
bfire85 over 1 year ago in reply to bfire85

Robontario If you are going to continue using Legacy, then you need to format the report to show MAX and MIN and omit the MEAS. Then double the greatest deviated between MAX and MIN report that as your measured value. Otherwise, use Geometric Tolerance GD&T library (2020R2+) and it will report it as it should per the standard. Happy GD&T-ing.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
Kai Kendall over 1 year ago

+1.5/-1.5, when aligned to ABC.

If you're using FCF dimensions in PC-DMIS, what you need to enter will vary, depending on software version, service pack, etc.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
RobOntario over 1 year ago in reply to bfire85

bfire85 Using the attached as an example: MAX 0.821 MIN -0.685, no MEAS DEV 0.821 x2= 1.642, still passed. Thank you.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
RobOntario over 1 year ago in reply to Kai Kendall

Yes, aligned to ABC, mine is 2015.1 or 2019.2
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
Neil Challinor over 1 year ago

This is a link to a handout that you can download explaining how profile is reported when using Legacy dimensioning, XactMeasure or Geometric tolerance commands. Only Geomoetric tolerance commands report in accordance with ASME Y14.5 2018 (using the single value method detailed in Y14.5.1 2019). Legacy & Xactmeasure use the older, two value method and require you to compare bot the max AND the min against the upper and lower tolerance limits to prove conformance.

https://support.hexagonmi.com/s/article/Geometric-Tolerance-GD-T-handout-for-PC-DMIS-2020R2-version

As for your question about the amount of ± to apply - a profile tolerance of 3 means ±1.5 from the nominal surface so MAX can not exceed +1.5 and MIN can not exceed -1.5.
In answer to your other question
Using the attached as an example: MAX 0.821 MIN -0.685, no MEAS DEV 1.506X2=3.012, but it showed failure? Correct?

No. For the single value method, the largest amount of deviation from nominal is +0.821, 0.821*2 = 1.642 which is less than 3 and therefore, within tolerance.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel
bfire85 over 1 year ago in reply to bfire85

Robontario, Correct as the individual deviations are within +/- 1.5 as well.
Cancel
Vote Up 0 Vote Down

Sign in to reply

Cancel