Diametral true position of two pins mounted perpendicular to primary datum (cylinder) no secondary or tertiary.

[[Br...]]

I know this should be a best fit alignment as it is 2x. The only blue print basics for the pins are to the center of the primary cylinder (z-axis) of which would be in the x-origin and the values are not the same. Since there is no z-origin and and no blue print basics off of the y-origin (but could be implied by projections of the pins piercing the cylinder(blue print basic radius). I imagine that the best fit would have to be able to rotate and translate. Does anybody have any onsite on this?

[[Lo...]]

Can you supply a visual aid? Yeah I'm one of those guys.

[[Br...]]

Excuse my hand drawing skills but in a sense this is it datum A is the cylinder and their are 2 dowel pins protruding from it.

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[[Da...]]

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And you are working to ASME standard, right?

[[Ro...]]

Since your protruding nubbs are very small, i would treat them as circles and just do an "X only" true position, individually.
Using circles instead of cylinders will also give you your MMC bonus, cylinders will not.
A recent heavily debated post recently went thru all the advanced differences of MMC vs MMB and weather or not you should get bonus at all, but I'm in the camp of primary modifiers are there for a reason.
That post is here viewtopic.php?f=13&t=5175&hilit=bonus

Additionally, i would also use a circle on the Datum A cylinder, maybe 8 point circle right at the Z height of your pins, or constructed using formulas, because the origin of a cylinder is at the end where the trihedron is. Depending on how long the cylinder is or the form error this could cause the center point to be off significantly at the point of your TP. That could help avoid fights with the production and setup staff.

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[[Lo...]]

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I believe you may be on to something, Roberto. That's the way I have done, similar, inspections in the past. Because its 2x, try checking the position as a pattern. just an idea.

[[Lo...]]

I checked these posts as a pattern, this correlated with measurements done open plate. Checking them individually wasn't matching what we saw on the surface plate. So keep this in mind as an option. It worked for me and made everyone happy.

[[Br...]]

I originally tried as Roberto suggested and only reported in X but was questioned per the diametrical values. So then I used the two posts as a pattern and that is how I best fit, rotating around Z and translating. This brought a much better result. Thanks guys! BB

[[SH...]]

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I have used cylinders and I got MMC on cylinders.
His datum A is not a FOS, it does not have opposing points. Does this not violates the standards?.