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Datums call out @ part center is correct? 4
- Thread starter darshan84
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darshan84 said:
Yes you can have a datum derived from some defined feature (such as part overall dimension) which is effectively the center plane of that feature.
thread1103-292841 and plenty of others touch on this.
Posting guidelines faq731-376 (probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484
What is Engineering anyway: faq1088-1484
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- #6
Darshan84,
No, you can't use a part centerline to define a datum as shown in your examples. The datum feature symbol must be associated with a particular feature, or features.
Evan Janeshewski
Axymetrix Quality Engineering Inc.
No, you can't use a part centerline to define a datum as shown in your examples. The datum feature symbol must be associated with a particular feature, or features.
Evan Janeshewski
Axymetrix Quality Engineering Inc.
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1
- #8
darshan84 - did you look at the links I provided?
The first response in the thread I linked had this illustration:
The first response in the thread I linked had this illustration:
Posting guidelines faq731-376 (probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484
What is Engineering anyway: faq1088-1484
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- #9
As stated above, you can't have a datum symbol attached to a non-touchable center. There are a couple of reasons, but the main one is that we don't know exactly what center is being referred to: Is it the center plane derived from the outside width? Inside width? Middle plane of the holes' location? And so on.
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
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1
- #10
PaulJackson
Automotive
Here is a functionally blind option.
Paul
Paul
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1
- #11
Darshan84
You sure will ask why I can't use the center line as a datum feature, here is the answer for you. Even ISO GPS not allow the datum symbol place on the center line on the new standard.
From the point of view on datum point (0.0,0.0) on your last post, use the hole pattern as a datum feature is a good practice as mentioned by Paul.
Season
You sure will ask why I can't use the center line as a datum feature, here is the answer for you. Even ISO GPS not allow the datum symbol place on the center line on the new standard.
From the point of view on datum point (0.0,0.0) on your last post, use the hole pattern as a datum feature is a good practice as mentioned by Paul.
Season
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- #12
powerhound
Mechanical
Just a point of interest. Your callout for Datum C is also wrong for the reasons stated above.
John Acosta, GDTP S-0731
Engineering Technician
Inventor 2013
Mastercam X6
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
John Acosta, GDTP S-0731
Engineering Technician
Inventor 2013
Mastercam X6
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
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