Double Maximum Material Condition?
Double Maximum Material Condition?
(OP)
During the inspection process I ran across several features (round slots and holes) which had not one, but two MMC symbols in the position block. That is to say, the second MMC symbol was not for a Datum of size, but in the same segment of the position block as the position tolerance itself:
|TP|DIAM .007(M)(M)|A|B(M)|C|
This appears in several places on the print, so I'm fairly certain it isn't a "typo." Does this mean the design engineer is intending to double the bonus derived from the size of the features?
Thanks for the help,
Adam
|TP|DIAM .007(M)(M)|A|B(M)|C|
This appears in several places on the print, so I'm fairly certain it isn't a "typo." Does this mean the design engineer is intending to double the bonus derived from the size of the features?
Thanks for the help,
Adam





RE: Double Maximum Material Condition?
The feature control frame as described in not in compliance with either the ASME 14.5M- 94 or 2009 standard. I would suggest that you go back to the Designer and ask for an explanation. You will find out that the Designer just doesn't know.
If I were in your posiition (and I was at one time) disregard the second MMC.
Dave D.
www.qmsi.ca
RE: Double Maximum Material Condition?
Thanks for the quick answer! I think the print was drawn by a rookie engineer, and judging by the number of dimensions which were completely omitted in the original rev (added in ECOs later), he probably just needs more practice and constructive feedback. I'll let him know about the problem.... thanks again!
~ Adam
RE: Double Maximum Material Condition?
B = (MMC)^2
Evan Janeshewski
Axymetrix Quality Engineering Inc.
www.axymetrix.ca
RE: Double Maximum Material Condition?
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: Double Maximum Material Condition?
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Double Maximum Material Condition?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Double Maximum Material Condition?
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Double Maximum Material Condition?
RE: Double Maximum Material Condition?
RE: Double Maximum Material Condition?
Please elaborate on your post. I haven't seen that one in the standard. Where is it?
Powerhound, GDTP T-0419
Production Manager
Inventor 2010
Mastercam X3
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
RE: Double Maximum Material Condition?
RE: Double Maximum Material Condition?
Thanks, that's one I've never noticed.
As far as I'm concerned you get a star for that.
Powerhound, GDTP T-0419
Production Manager
Inventor 2010
Mastercam X3
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
RE: Double Maximum Material Condition?
Paul
RE: Double Maximum Material Condition?
Dave D.
www.qmsi.ca
RE: Double Maximum Material Condition?
Here's the example from the standard:
PRP|dia 0(M) dia 0.1 MAX |A|
So the intent seems to be that we want the surface of the feature to conform to a boundary, but we also don't want it to get too tilted. This really acts like two perpendicularity tolerances for the same feature, one at MMC and one at RFS:
PRP|dia 0(M)|A|
PRP|dia 0.1|A|
I guess the committee thought that having two different orientation tolerances on the same feature would be confusing. Inserting another tolerance value and the word MAX into the FCF, in just this one instance, is much more clear.
Evan Janeshewski
Axymetrix Quality Engineering Inc.
www.axymetrix.ca