I have a callout that is a Position of 0.01 MMC | C | D | with a profile of a line of .005 of an irregular feature (Dovetail). How would you do this to meet the print callout?
Profile of a surface 0.01 | C | D |, Profile of a line 0.005? Any other suggestions?
How is this an invalid use? It is clearly defined in ASME 14.5-2009 and 2018 section 8.8. My problem is how to make PC-Dmis check it. This is a simple overlay/optical comparator check or gage check.
It is illegal because the line scan from X<->Y is a feature of form and not a feature of size.
In order for a plane or line to be considered with MMC it would need to be included as part of a width (therefore making it a feature of size)
I have found that "usually" when PC-DEMON doesn't allow me to check something the way some "engineer" drew it, it is usually the "engineer" that is incorrect. in this instance, vpt.se is absolutely correct. this is an invalid use.
Would this not be considered an Irregular feature of size?
1.3.32.2 (B):
A directly toleranced feature or collection of features that my contain or be contained by an actual mating envelope other than a sphere, cylinder, or pair of parallel planes.
I'd be happier with a position of a surface to constrained datums, personally, but I'm not 100% sold that this isn't valid, just maybe not the best way to get it checked and end up with correlation between inspectors on different CMM's.
You'd have to ask, but I presume the engineer wants the centerline of the dovetail opening at a specific position primarily within a position of .010 (linear zone, he didn't call diametric which would make it invalid). And then check the form for refinement within .005.
If I was going to try this on a CMM, I'd pick up both sides of the dovetail, construct a centerpoint and tolerance that.
I would do it in cross-sections as shown.
Many times.
I'd do it in legacy so I could enforce ONLY the one axis for evaluation (right to left as in your drawing cross section).
I'd also be angry he didn't give me a flat on the "Y" side of the groove. Because of that, you can't check the corner, it won't be there after deburr, especially not in a way that will generate two equal and opposing points from which to make your centerpoint.
You're gonna have to go down the wall a bit with a stylus big enough it won't shank. I'd use a 3mm stylus and constrict my prehit/retract moves.
measure a BUNCH of points all along that, make a set out of them, position the set, the align to the set and dimension each point as +/-0.0025 to that alignment
