Basic GD&T question 4

[artnmotion]

First of all I am a beginner with GD&T....so forgive me if I am totally off.

Do all BASIC Dim's emanate from Datum Features? Or can they originate from features that are not datum features?

Thanks!

-Art

 

[pmarc]

Attached is an example of datum planes defined by basic dimensions where no tolerance is involved. Not all of the basic dimensions originate from a datum, but all of the datums use basic dimensions.

Could you please clarify:
Which attached example is this statement about? What do you mean by: "Not all of the basic dimensions originate from a datum, but all of the datums use basic dimensions"?

 

[tbuelna]

pmarc-

Sorry for the missing link. Take a look at this attachment.