Section of a Section
Section of a Section
(OP)
Where is it in the ASME drawing standards that it says you shouldn't have a 'section of a section'.
I thought it would be in Y14.3 but I don't see it. I'm sure it's come up on this forum before but a quick search didn't show it.
Or am I making this one up
I thought it would be in Y14.3 but I don't see it. I'm sure it's come up on this forum before but a quick search didn't show it.
Or am I making this one up
KENAT, probably the least qualified checker you'll ever meet...





RE: Section of a Section
"The cutting plane should be shown through an exterior view and not through a sectional view."
Of course, it says "should" so I guess that, while it may be preferred practice, it is still not mandated.
RE: Section of a Section
3.2.5 "The cutting plane should be shown through an exterior view and not through a sectional view."
Not sure how I missed it, agree on the pesky 'should'.
Star for you.
KENAT, probably the least qualified checker you'll ever meet...
RE: Section of a Section
It looks like I'm falling behind the current standards.
I think I'll wait until 14.5 is officially released before I ask for new ones.
RE: Section of a Section
I find I often use sections of sections when making assembly drawings. Often it is unavoidable.
Wes C.
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RE: Section of a Section
However, one issue with a section of a section. Should the section of the section show a projection of only the part 'left' after the section, or a section of the complete part at that point.
While I've been tempted, I don't think I've ever done it. I've always found it can be avoided.
However as you point out, the standard doesn't explicitly forbid it.
KENAT, probably the least qualified checker you'll ever meet...
RE: Section of a Section
RE: Section of a Section
You've got me there. It is never truely unavoidable. I will say this though. I have found that while trying to stick to the rules explicitly, I often end up with a more confusing drawing.
Here is my example, where I will try to explane with words, since I don't want to take the time to draw it out....
I have a box that I install in an aircraft. The box is screwed into a clip from the inside. Firstly I have to point to the box to call it out in the installation. Then I take a section of the box to show the fasteners, how the holes are drilled and whatnot. I also would like to show how the fasteners stack up because there exists a shim, and it isn't immedatly apparant where it is placed in the installation of the box. I have two choices, I can go back to the original view and take another section 90 deg to the previous section, or I can take a section of a section.
I find that, in dealing with the fabricators doing the work, that there is often less confustion about what the drawing is attempting to achieve by showing a section of a section.
I guess the point is, if you are consistent, and conservative in your uses of "breaking the rules," and you do it specifically to address some a particular problem, then you'll probablly be ok. If you do willy nilly, whatever you want, you're just a some hack who should probablly go back to middle school and get some drafting instruction from someone who'll hand you a pencil, not a computer mouse.
Wes C.
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RE: Section of a Section
What really frustrates me is seeing a simple drawing where many rules are broken for no good reason other than laziness or lack of thought put into it.
RE: Section of a Section
As you say, most of the people around here would benefit from some drafting classes.
Personally, especially with the functionality of our CAD system, I've been hiding parts, with a note under the view saying which are hidden, a lot more lately. For assemblies where you basically have a bunch of stuff in a box then it works pretty well, just hide the lid or something rather than sections.
If I'm breaking the rules let me know
KENAT, probably the least qualified checker you'll ever meet...
RE: Section of a Section
Anyway, just playing devil's advocate.
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: Section of a Section
RE: Section of a Section
Chris
SolidWorks/PDMWorks 08 1.1
AutoCAD 06
ctopher's home (updated 10-07-07)
ctopher's blog
RE: Section of a Section
I'm opposed to section of a section not just because of what the standard says but for the reason I put above.
However, it isn't completly forbidden although I've never found a situation it couldn't be avoided though.
KENAT, probably the least qualified checker you'll ever meet...
RE: Section of a Section
Have you considered a cutaway on the box that would show the heads of the fasteners? Then you could take a section thru that view of the fastener.
RE: Section of a Section
Yes, there is that wishy-washy ASME committee "should". Those guys just can't take a stand for what is right, for fear that someone, somewhere might object. I miss the definitive and contractural "shalls, musts', and wills'" found in the old Mil specs that precluded arguements.
RE: Section of a Section
Believe it if you need it
or leave it if you dare
RE: Section of a Section
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: Section of a Section
KENAT, probably the least qualified checker you'll ever meet...
RE: Section of a Section
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: Section of a Section
Regards,
Namdac
RE: Section of a Section
Now, with cad you can just add multiple sheets instead and easily have all the views you want, and also with something like Solidworks I don't think you can even take a section of a section.
RE: Section of a Section
SW does allow you to do it, it was an SW drawing I was looking at when I posted this. Don't ask me how though, I've only used our other CAD system.
KENAT, probably the least qualified checker you'll ever meet...
RE: Section of a Section
RE: Section of a Section
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group