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Hex hole as a datum feature
Seems to me like it would be acceptable were it not for the gage pin bit, which I don't understand why they would ever include that. Just makes it confusing and ambiguous. Datum C as sets of parallel planes makes sense. Like creating a datum from the length or width of a rectangular slot.- e1baz_
- Post #2
- Forum: Drafting Standards, GD&T & Tolerance Analysis
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Confusions on drawing
All variations are possible to inspect with a CMM. Hypothetically. You'd probably rather a vision system for something this small. That's what I use anyways. ProposedDrawing2 looks like something someone would post on reddit to show off how much their "knowledge" of gd&t. Something tells me it...- e1baz_
- Post #4
- Forum: Drafting Standards, GD&T & Tolerance Analysis
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Total Runout - Long Shaft
Having been an inspector myself I will say it is entirely possible (likely even) that the other shops are not inspecting this feature at all or using a half-measure just to verify it "seems ok enough" - 0.005" runout for that length is a bit over-the-top. Even if you had a 10ft CMM you'd have to...- e1baz_
- Post #18
- Forum: Drafting Standards, GD&T & Tolerance Analysis
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Basic Dim on Series of Holes
If you want to make your drawing needlessly ambiguous and confusing (in practice hardly any inspector cares about GD&T) then go ahead and do it like you've shown. I tend to prefer simple and obvious.- e1baz_
- Post #8
- Forum: Drafting Standards, GD&T & Tolerance Analysis
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GD&T: How to inspect tertiary datum feature position tolerances?
If using a CMM or similar, you would do your initial alignment to the A plane, then set your x,y origin to the B cylinder. Then to report your true position it would be the distance in terms of x perpendicular to the midline of the slot. The maximum deviation in terms of x would be +/- half of...- e1baz_
- Post #6
- Forum: Drafting Standards, GD&T & Tolerance Analysis
