Does anyone here have any experience transitioning to a CAD only or a CAD + limited 2D drawing approach?
Tangentially: from a process capability viewpoint - True Position is essentially a go/no go attribute check but variable data is needed to establish and track capability which is all well and good, just insist the BASIC dimensions are reported. . . but what about tolerance? You need a tolerance for those basic dimension to perform full function SPC analysis. Do you calculate the largest square that fit in the circle and use 1/2 of that size as ± for the BASIC or what?
I don't have experience with the actual process of transition, but I've been working with limited dimensions drawings for the majority of my career. I haven't actually seen the standard since 2012, but nearly everything I see is limited dimension.
I will say that limited dimension drawings are not always appropriate, and it may be a little bit of an art deciding when it is and isn't. I think a general rule, in my experience and opinion, would be that things like body components and structural components with few holes and mostly complex surfaces should be limited dimension (mostly just surface profiles), and things like precision machinings, casting and moldings would be more appropriate to see directly dimensioned.
Bearing in mind that limited dimension drawing also doesn't mean "directly dimensioning is not allowed".
Do you have any specific questions about it?
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I still don't have an answer that I feel is satisfactory on TP capability. I think it's badly in need of a major overhaul. The safe bet would be to use (TPtol*.7071)/2 for your tolerance on the basics, but that doesn't really give you the full picture. And calculating based on the unilateral TP tolerance is the worst thing ever... (It wouldn't be as bad if it was unilateral in a single direction, instead of being diametrical).
Fortunately, most of my 0 at MMC are on Datum B and C, which is hilarious on a stamping. Datum B is always 0, and Datum C rotation is always... 0. Meh.
(It wouldn't be as bad if it was unilateral in a single direction, instead of being diametrical).
