Symmetrical Dimension
Symmetrical Dimension
(OP)
I just saw something "new" on a drawing, and before I question it(and the detailer), I'd like to know if this is common, or from some standard. I've done a search, a google search, and looked thru y14.5, and have not found it.
The part on the drawing is symmetrical, so all of the dimensions that show symmetrical features read like this "=1.000=", with a tiny equals sign, before and after it.
I've seen the symmetrical centerline used, per y14.5, but never these little equal signs.
Thanks,
Dave
The part on the drawing is symmetrical, so all of the dimensions that show symmetrical features read like this "=1.000=", with a tiny equals sign, before and after it.
I've seen the symmetrical centerline used, per y14.5, but never these little equal signs.
Thanks,
Dave
-Dave
Everything should be designed as simple as possible, but not simpler.





RE: Symmetrical Dimension
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Symmetrical Dimension
Perhaps the company has it own standard which will provide a clarification. Otherwise, in these days of computer generated drawings, my opinion is that symmetry symbol on a drawing should be avoided.
I have never seen the method you described. Over 50 years.
RE: Symmetrical Dimension
Chris
SolidWorks 08, CATIA V5
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion
RE: Symmetrical Dimension
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: Symmetrical Dimension
Given that none of you have seen it before, and I've never seen it...unless he comes up with a good source, it's out.
Thanks everyone!
-Dave
-Dave
Everything should be designed as simple as possible, but not simpler.
RE: Symmetrical Dimension
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: Symmetrical Dimension
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: Symmetrical Dimension
Dean Viviani
RE: Symmetrical Dimension
I doubt it applies to any recognised standard.
RE: Symmetrical Dimension
Those types of symbols are nothing but a symbolic representation for symmetry..most of the american companies doesnt follow or use such things..but european countries like..italy,german,,etc use such symbols..they give more importance to those symbols..if you can open the attached image here,,take a glance,,in such situation we can delete 2.5mm dimsn both sides and keep =5=,,which makes clear view,,this is much concern when we do drafting for typical profiles or when the detail is meshy
sorry for grammer mistakes
RE: Symmetrical Dimension
all: As a side note, at a past employer, we used a centerline, and the note "Sym about this plane UOS", before they went to Y14.5.
-Dave
Everything should be designed as simple as possible, but not simpler.
RE: Symmetrical Dimension
In your example (which is common in the U.S. as well), if the both 2.5's are removed, there is no tolerance to the centerline, and therefore the hole and the centerplane itself is essentially undimensioned. Unless a standard or drafting manual specifically states the centerline splits the tolerance (or in some other way is toleranced), any further dimensions off the centerplane would have no tolerance applicable to them.
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: Symmetrical Dimension
RE: Symmetrical Dimension
I agree with you..when the hole is tolerated,then its should be essntially given 2.5mm dimension with tolerance,..In other task when hole is not tolerated,i think that is ok????
sorry for grammer mistakes
UG NX5,SOLID WORKS
RE: Symmetrical Dimension