Composite FCF - Datums Repeated in Lower Segment
Composite FCF - Datums Repeated in Lower Segment
(OP)
Hello All,
I have a drawing with a composite feature control frame:
(Upper segment)Dia .0045 (M)/D/H/P
(Lower segment)Dia .0015 (M)/D/P
I thought the lower segment MUST repeat the primary and secondary in the upper segment (if needed).
So I think it should be:
(Upper segment)Dia .0045 (M)/D/H/P
(Lower segment)Dia .0015 (M)/D/H
In ASME Y14.5M-1994, Section 5.4.1.2 says, "In Fig. 5-20, the lower segment of the composite feature control frame repeats datums A and B." But that's all I could find and that's not going to win my argument.
First, am I correct by thinking this ... then, does anyone know of a better area to point me to in the standard?
I have a drawing with a composite feature control frame:
(Upper segment)Dia .0045 (M)/D/H/P
(Lower segment)Dia .0015 (M)/D/P
I thought the lower segment MUST repeat the primary and secondary in the upper segment (if needed).
So I think it should be:
(Upper segment)Dia .0045 (M)/D/H/P
(Lower segment)Dia .0015 (M)/D/H
In ASME Y14.5M-1994, Section 5.4.1.2 says, "In Fig. 5-20, the lower segment of the composite feature control frame repeats datums A and B." But that's all I could find and that's not going to win my argument.
First, am I correct by thinking this ... then, does anyone know of a better area to point me to in the standard?





RE: Composite FCF - Datums Repeated in Lower Segment
RE: Composite FCF - Datums Repeated in Lower Segment
Ref. last sentence in 5.4.1(b):
Where datum references are specified,
one or more of the datums specified in the upper
segment of the frame are repeated, as applicable, and
in the same order of precedence, to govern the orientation
of the FRTZF.
RE: Composite FCF - Datums Repeated in Lower Segment
Thanks
Season
RE: Composite FCF - Datums Repeated in Lower Segment
Does that answer your question?
RE: Composite FCF - Datums Repeated in Lower Segment
Season