Extension of Principal?
Extension of Principal?
(OP)
Can a circular pattern of features be used as a datum (see attached)?
I have my own ideas on this, but there is no example of this situation depicted in Y14.5 that I can find.
Thanks!
I have my own ideas on this, but there is no example of this situation depicted in Y14.5 that I can find.
Thanks!
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV





RE: Extension of Principal?
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Extension of Principal?
I knew I had learned it somewhere, but I guess I only checked Section 7.
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
RE: Extension of Principal?
Should be the pattern callout at MMB or RMB?
See here for the discussion (one place is here, but there are plenty more)
http://www.eng-tips.com/viewthread.cfm?qid=305667
RE: Extension of Principal?
A related question - if the pattern were located with a composite positional tolerance, could it still be used as a datum? I don't see why not, but that doesn't mean I'm not overlooking something.
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
RE: Extension of Principal?
The pattern can still be used as a datum feature, even if it was located with a composite position tolerance. I don't know of any reason why it couldn't.
The composite position tolerance might come into play when calculating the size of the datum feature simulator, depending on how the datum feature is referenced (i.e. what the higher precedence datum features are).
Evan Janeshewski
Axymetrix Quality Engineering Inc.
www.axymetrix.ca
RE: Extension of Principal?
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
RE: Extension of Principal?
RE: Extension of Principal?