Creation an origin with a bore pattern

[[Br...]]

I am a little confused with the FCF stating hole positions from AB and then there is a Basic dimension (119). So how would the best way to get the True Positions of Item #11? This print is referencing ASME 14.5-2009, but I only have the ASME 14.5-2018

[[Cl...]]

Looks like a sheet metal part. Datum -A- is the top (Plane) of the part? In my opinion unless that 119 centerline is Datum -A-, it got nothing to do with the tp's.

Base Alignment - whatever is the largest plane surface for primary (spatial). A 2d line on one edge for planar (Y+) and a point on the front edge for the Y origin and loop it.

Measure datum's A & B. Pick up the 11 holes and report XY deviations from basics. Pretty straight forward to me.

[[Ma...]]

That basic 119 is there for other holes.

I am curious how you will handle that B(m). It's pattern of top left hole and bottom right hole. Not sure how can Calypso do that.

There are 13x dia 6 holes.

[[Br...]]

Yes Datum A is the top surface sorry I forgot to mention this. I have always measured holes or TP's from the Feature control frames. Yes it is straight forward and Just an FYI the part is aligned on the top left hole and the bottom right hole as these are marked as Datum B and using the hole straight across to create the planer rotation.  I think you both for your visions on the part print and your interpretations, the part is made of aluminum material.

[[Ri...]]

Looks like the 119 Basic is to establish Section Z-Z (Center Line).

I get this on aerospace prints all the time, it is there for Sec Z-Z and whatever is shown in Sec Z-Z.

[[Da...]]

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Since there is no Datum A shown in this view, and we have 1 more hole than called out, I'm expecting that missing hole is elsewhere on the print, likely as a tertiary datum.

FWIW, a callout in the form of A|B(mmc) is often used as a rotational element and is usually called out a datumC, making that hole essentially a unilateral position, since the Y-axis component as such would be zero. But I don't see a datum callout here. What I would EXPECT is that this callout would be a single diameter, would be declared datumC, then the OTHER 11 holes would be dimensioned to A|B(mmc)|C(mmc). That would make the most sense. But often, 'military prints' don't.....

If that is the case, I've found that Calypso makes such 'skewed' alignments quite easy. I would just create a cartesian alignment based on datumB, and rotated to the line the left column of holes makes, go ahead and just measure all the holes, then go back and create a skewed alignment off of which-ever one is declared datumC and take the positions off of THAT alignment. In this respect, Calypso has a clear advantage over my old PC-DMIS software (as well as CMM Manager, MCosmos, MeasureMax, GeoMet, and all the other old CMM programs I've used over the last 20 years).

FWIW, I think I recognize this print style as that of a certain supplier of components in the "ITAR realm", so I'd be very careful about what you cut-and-paste here. If that IS the case, keep in mind that 'they' seem to leave production of their prints mostly to their engineering co-ops, and it often takes communication with the project engineer to get errors corrected and intentions explained.

Edited February 1

[[Ma...]]

Have you look closely at datum B? There is "2x at holes marked a" - it's top left and bottom right.

Datum A is plane as author stated later. There is no datum C used and either question about that, so don't bring here something what was not asked for - speculations.

[[Da...]]

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OK, so all holes ARE accounted for. Still, this oversight of mine opens up NEW questions:

So, you are saying that datumB is both origin AND rotational element? That really makes my brain hurt; how can we set up a cartesian coordinate system with only a primary and a secondary datum? Or does it matter whether the second "a" hole is precisely where it is supposed to be, with no dimensioning on how accurate it's actual placement is? The print seems truncated at the right, but I see a line which looks like it probably corresponds to a Y-axis dimension for that second "a" hole. Is this dimension also basic?

If the second "a" hole is basic, then why is it not separately dimensioned as datumC and used as a proper rotational element? If it's NOT basic in the Y-axis, why is it in the X-axis? There are enough inconsistencies to general tolerancing norms here to warrant clarification from the customer. If the centerline can be assumed to be a rotational element, then it needs to be declared as the tertiary datum. I don't believe it can be modified (not being a feature of size), but it would certainly be a rotational datum.

Otherwise, calling 2 holes a datum without specifying a rotational element would suggest a skewed datum rotated at what appears to be about a 60° angle to the print coordinates. I have some customers who do this, and it's really fairly easy to calculate with Calypso, but a real pain to do manually, having to 'trig out' each component on a spreadsheet. This arrangement would also mean that second "a" hole would not be dimensioned, since no feature may be dimensioned to itself (dimensioning datumB to datumB).

Now my brain REALLY hurts. I spent an entire semester in engineering school studying this, and it's still as confusing today as it was 30 years ago when it was new. It's more like studying law than anything useful for engineering. I'm going back to my suggestion based of needing to call the project manager for clarification.

[[Ma...]]

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Datum B is pattern of two holes marked as "a" - only thing i don't know if is possible is using that with MMB modificator.