JacobCheverie "By default" this is mere word play in Y14.5. I'm confused by your statement, are you saying this isn't allowed? If so, see the
bold, below.
Y14.5 2009 - 4.19: "A simultaneous requirement is where two or more geometric tolerances apply as a single pattern or part requirement. A simultaneous requirement applies to position and profile tolerances that are located by basic dimensions, related to common datum features referenced in the same order of precedence at the same boundary conditions. In a simultaneous requirement there is no translation or rotation between the datum reference frames of the included geometric tolerances, thus creating a single pattern. Figures 4-39 and 4-40 show examples of simultaneous requirements. If such interrelationship is not required, a notation such as SEP REQT is placed adjacent to each applicable feature control frame. See Figs. 4-41 and 7-54 and para. 7.5.4.2.
This principle does not apply to the lower segments of composite feature control frames. See para. 7.5.4.2.
If a simultaneous requirement is desired for the lower segments of two or more composite feature control frames, a notation such as SIM REQT shall be placed adjacent to each applicable lower segment of the feature control frames.
This is 100% a valid call-out - multiple OEM's (Boeing, Sikorsky, SAAB, etc..) view and engineer in such fashion. If you think about it, you have a traditional
fully constrained upper segment (3 Datum Planes/ABC), and a composite (1 Plane/ A) SIMTOL does absolutely nothing for the upper segment, the under constrained composite is what you'll want to be simultaneously evaluated...
Which, PC-DMIS does not calculate - it's worse, it
100% misleads you into believing it actually is being evaluated simultaneously, when it's not supported, even though this is a valid call-out to many.
"Do you have a concrete example in which the math that PC-DMIS is performing is incorrect?" So, I would say the "math" isn't being preformed correctly - as it's not even being done lol. With all the redundant "warning" messages PC-DMIS has,
there's zero excuse for not having, "SIMTOL error, composite tolerance cannot be simultaneously evaluated"
I was completely burned by this. There is also other, well-respected Senior members of this form that could also be burn like I was, referencing my post above again.
"Do you have a concrete example in which the math that PC-DMIS is performing is incorrect?" Outside of, composite not being evaluated simultaneously.... Look at the screenshot below of a SIMTOL Single Segment FCF's for groups of holes. Notice how PC-DMIS calculates MMC bonus of
.010" (black box) when I have a
+.002 -.001 tolerance (red box)...
JacobCheverie "By default" this is mere word play in Y14.5. I'm confused by your statement, are you saying this isn't allowed? If so, see the
bold, below.
Y14.5 2009 - 4.19: "A simultaneous requirement is where two or more geometric tolerances apply as a single pattern or part requirement. A simultaneous requirement applies to position and profile tolerances that are located by basic dimensions, related to common datum features referenced in the same order of precedence at the same boundary conditions. In a simultaneous requirement there is no translation or rotation between the datum reference frames of the included geometric tolerances, thus creating a single pattern. Figures 4-39 and 4-40 show examples of simultaneous requirements. If such interrelationship is not required, a notation such as SEP REQT is placed adjacent to each applicable feature control frame. See Figs. 4-41 and 7-54 and para. 7.5.4.2.
This principle does not apply to the lower segments of composite feature control frames. See para. 7.5.4.2.
If a simultaneous requirement is desired for the lower segments of two or more composite feature control frames, a notation such as SIM REQT shall be placed adjacent to each applicable lower segment of the feature control frames.
This is 100% a valid call-out - multiple OEM's (Boeing, Sikorsky, SAAB, etc..) view and engineer in such fashion. If you think about it, you have a traditional
fully constrained upper segment (3 Datum Planes/ABC), and a composite (1 Plane/ A) SIMTOL does absolutely nothing for the upper segment, the under constrained composite is what you'll want to be simultaneously evaluated...
Which, PC-DMIS does not calculate - it's worse, it
100% misleads you into believing it actually is being evaluated simultaneously, when it's not supported, even though this is a valid call-out to many.
"Do you have a concrete example in which the math that PC-DMIS is performing is incorrect?" So, I would say the "math" isn't being preformed correctly - as it's not even being done lol. With all the redundant "warning" messages PC-DMIS has,
there's zero excuse for not having, "SIMTOL error, composite tolerance cannot be simultaneously evaluated"
I was completely burned by this. There is also other, well-respected Senior members of this form that could also be burn like I was, referencing my post above again.
"Do you have a concrete example in which the math that PC-DMIS is performing is incorrect?" Outside of, composite not being evaluated simultaneously.... Look at the screenshot below of a SIMTOL Single Segment FCF's for groups of holes. Notice how PC-DMIS calculates MMC bonus of
.010" (black box) when I have a
+.002 -.001 tolerance (red box)...
