I tried to create the FCF shown on the print using the Xactmeasure true position, but I had a error message pop up. So I'm just looking for someone to confirm that the print has Bad GDnT.
Just asking, If it was a composite callout, the print would be 100% wrong. Cannot have different datum in 2nd callout. Now, the question is, since it is a 2 segmented callout, is the print legal? I run into this all the time with our prints. I am hoping there is some GD&T guru out there that can answer this. Xact measure will not allow it whether its composite or 2-segmented.
well I read that true position of a hole referenced back to the plane on which it sits is basically the same thing as perpendicularity. maybe that's what they want to know.
so I figure they want to see if it is in the correct position referenced to Datum ABC but also want to know if it is perpendicular to the plane on which it lays on... QUESTION MARK. at least that's what I'm understanding.
I tried to create the FCF shown on the print using the Xactmeasure true position, but I had a error message pop up. So I'm just looking for someone to confirm that the print has Bad GDnT.
ASME Y14.5 2009, section 7.5.1 (b) (3) discusses the 2nd tier/lower frame of the composite position dimension, which they call the 'Feature Relating Tolerance Zone Framework' or FRTZF.
""Where datum feature references are specified, one or more of the datum feature references specified in the upper frame are repeated, as applicable, and in the same order of precedence, to constrain rotation of the FRTZF."
So, this is instructions on Doing It Right. The writing style of this standard does not include examples of Doing It Wrong for each and every thing, because that would turn a 214 page document into a 200,014 page document - instead they just assume that people will do it right as written and shown. Unfortunately some designers tend to think that it's like a motorsports rulebook: if it's not explicitly declared Wrong it must be OK, right? Nope. The verbiage states that the datum features are repeated in the same order of precedence. Slapping a different datum in there is wrong.
As noted, your only recourse is to make that 2nd tier a completely separate dimension.
hopefully Josh finds this thread and can shed some light.
I would have never seen it if you had not alerted me to it, thank you. I really should patrol this section more often.
The op does not show a composite frame. It is multiple single-segments.
Perhaps a better explanation would be found in
7.5.5 Multiple Positionsl Tolerances for a Pattern of Feature of Size.
If different datums, different datum modifiers, or the same datums in a different order of precedence are specified, this constitutes a different datum reference frame and design requirements. This is not to be specified using the composite positional tolerancing method. A separately specified tolerance, using a second sinlge-segment feature control frame is used, including applicable datums, as an independent requirement. See Fig. 7-55
I know the op does not have a pattern, but I think this is how it should be done.
