Automotive Help

[[To...]]

We're looking at a drawing from a primary automotive parts supplier and I'm looking for some feedback from any of you guys that do a lot of work in automotive in the US. I've included a snippet from the drawing and have questions on what the 2 circled items usually indicate. There was discussion regarding a gage r&r but am wondering if a typical gage r&r for automotive would be 100% of the part or a set of critical dimensions. Any feedback would be greatly appreciated.
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[[Cl...]]

My co-worker informed me that he thinks possibly the D070 is a feature number and the 002C is a revision number?

[[Ke...]]

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That jives with what I remember... but that was 13 years ago (lol)

[[Ma...]]

Yes, it looks like balloon numbers and revision. Looks similar to some of our customer prints.

[[Ri...]]

Looks like a GM print. 🙂

I agree with above.

[[To...]]

DOH Yes, you guys are right. The drawing is at Rev 002 and each of the circled symbols are 002 and the letter is listed in the revision legend. I knew I could count on you guys.

Any thoughts on capability studies being 100% of the part?

[[Ke...]]

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It's usually just a few characteristics

[[Ri...]]

They should have some sort of SC (special characteristic) symbol on the drawing. In the notes it should denote what each one looks like.

Typically it is only a handful of dimensions - they aren't as crazy as other companies.

[[Ma...]]

We do capability studies mostly on critical characteristics only.
On our prints these are marked as black or white diamonds, but we've also seen some with like a bubble arrow sometimes with a number in it or black and white or solid black circles.

[[To...]]

I tend to agree that studies are usually on a handful of dimensions but I do very little in the automotive world. I was told by the vendor, who is quoting the manufacturing of this part and looking for a CMM, that the customer is specifying every dimension with the numbered oval symbol, which is on every dimension, note, etc., on the drawing. Plus, the customer is looking for 10% or less on the study. Most of the tolerances are pretty normal but there is a diameter with .025 tolerance and a perpendicularity and flatness requirement, both at .020. These parts are sintered metal to shape, so I'm guessing 10% might be a bit challenging.

I hope we get a more realistic understanding of what is really needed.

Thank you measuring heroes....

[[To...]]

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Nothing other the numbered oval shapes, which are on every single characteristic and note. There is 1 Safety Class symbol in the notes referring to cracks and other defects relating to the condition of the part, but that's it.

[[Ri...]]

Ohhh.... this is powdered-metal? Fun! That was what I worked with in my old-life.

Unless it's a small diameter, I doubt they are holding a .025mm tolerance as sintered. Typically there would at least have to be some sort of sizing, or machining operation.

I would challenge on the every dimension. Ford is the only one that I've seen that goes crazy like that (especially in the transmission world). GM tends to be more relaxed, but you never know when you get a young engineer who thinks that everything is important.