Datum Pattern Callouts
Datum Pattern Callouts
(OP)
I have a part drawing that contains 6 sheets.
A pattern of 2 holes is called out as Datum B on Sheet 1.
I need to identify Datum B on the other sheets, but it's not necessary to callout the size of the holes. What is the proper way to do this (if there is a proper way)?
Do I need to callout the hole sizes every time?
Would it be ok to have a leader with "2x" and Datum B identifier attached to the leader?
A pattern of 2 holes is called out as Datum B on Sheet 1.
I need to identify Datum B on the other sheets, but it's not necessary to callout the size of the holes. What is the proper way to do this (if there is a proper way)?
Do I need to callout the hole sizes every time?
Would it be ok to have a leader with "2x" and Datum B identifier attached to the leader?





RE: Datum Pattern Callouts
Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services
RE: Datum Pattern Callouts
Do you really have to repeat the datum id? I know we often do it for clarity and it's ok to do it, but in your case it seems it might make it more confusing.
KENAT,
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RE: Datum Pattern Callouts
In my case I have Datum B fully defined on Sheet 1, but the other sheets have features that reference datum B. So my plan was to identify datum B on every sheet, but only have it fully defined on Sheet 1. I figured this would keep things clear without redundantly defining the datum.
RE: Datum Pattern Callouts
Normally we probably would repeat it on a second sheet to make it easier to read, but as I say, in your case it might add to confusion.
I certainly wouldn't expect it should be redefined as this requires double dimensioning.
KENAT,
Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently, or taken a look at posting policies: http://eng-tips.com/market.cfm?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Datum Pattern Callouts
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