Datums in Multiple Views
Datums in Multiple Views
(OP)
I have a drawing where it would be convenient to show 1 datum in multiple views. This is because I have to dimension off that datum in multiple views. What is the practice for this? Is the datum shown in one view and then labeled reference in the other views? Is the datum just shown "normal" in each view I dimension from it?
Thanks,
Anthony
Thanks,
Anthony





RE: Datums in Multiple Views
Believe it if you need it or leave it if you dare. - Robert Hunter
RE: Datums in Multiple Views
As I understand it, the datum (so long as applied to the same face/feature) can be shown in as many relevant views as you like.
It's not like double dimensioning.
In fact I've had checkers encourage me to show it more than once when it makes the drawing clearer.
KENAT, probably the least qualified checker you'll ever meet...
RE: Datums in Multiple Views
It's worth spending some time looking at it as the more familiar you get with it, the easier it is to find what you need. Don't get me wrong, I still sometimes can't find stuff & have to ask but I usually try and look before I ask. If nothing else I sometimes see other things that I remember for future use.
KENAT, probably the least qualified checker you'll ever meet...
RE: Datums in Multiple Views
I have only asked the questions that we could not find concrete answers to. "Equally Spaced" wasn't referenced anywhere so I didn't know if it was still allowed.
We couldn't find the answer to this no matter how much we searched. The old-timer was convinced it had to be shown as REF.
The Unilateral tolerance only shows that the amount of decimals should be the same as the amount shown in the nominal. The assumption must be made that the nil value must be shown. We have 1000's of military drawings that show .500+.005.
Thanks,
Anthony
RE: Datums in Multiple Views
"The assumption must be made that the nil value must be shown" No I dont' think so, 2.3.2 (which I typed in the other thread) seems quite clear on this to me. 'its dimension shall be expressed' hence the 0 to however many dp should be shown.
KENAT, probably the least qualified checker you'll ever meet...
RE: Datums in Multiple Views
Chris
SolidWorks/PDMWorks 08 2.0
AutoCAD 06
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RE: Datums in Multiple Views
You are asking good, valid questions.
I've been doing this sort of work for almost 30 years, and often have a hard time justifying why I do things a certain way. EQ SP is an example. I've always used it, but could not point to a standard where is is specified. I can usually find documentation to back me up, but not always. As you have noted, "old-timers" tend to be set in their ways. Just because I've always done something a certain way doesn't make that way valid, and I try to be open to differing opinions. If that differing opinion can't be backed up with documentation however, I generally stick to my guns.
Keep on asking questions. Keep us on our toes.
Believe it if you need it or leave it if you dare. - Robert Hunter
RE: Datums in Multiple Views
RE: Datums in Multiple Views
RE: Datums in Multiple Views
You may not have to change afterall. I think that the concensus is that EQ SP is a valid callout. See thread1103-208563: "Equally Spaced"
Believe it if you need it or leave it if you dare. - Robert Hunter
RE: Datums in Multiple Views
Anthony
RE: Datums in Multiple Views
RE: Datums in Multiple Views
I agree with ewh and others, ask lot's of questions. My previous post was just saying to research a little before you ask, which it turns out you are doing so good on ya!
KENAT, probably the least qualified checker you'll ever meet...