Ordinate Dimensioning
Ordinate Dimensioning
(OP)
Are tolerances applied to the origin in ordinate dimensioning?
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RE: Ordinate Dimensioning
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
TecEase, Inc. www.tec-ease.com
RE: Ordinate Dimensioning
Wouldn't that be like telling the machine the starting point has a tolerance?
Chris
SolidWorks 10 SP5.0
ctopher's home
SolidWorks Legion
RE: Ordinate Dimensioning
RE: Ordinate Dimensioning
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
TecEase, Inc. www.tec-ease.com
RE: Ordinate Dimensioning
However, the '0' is analogous to a datum in many respects.
Also just logically, if it has a tolerance, then using that dimension system seems almost unfeasible.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Ordinate Dimensioning
I do not think the answer for this question depends on GD&T standard used.
RE: Ordinate Dimensioning
RE: Ordinate Dimensioning
Powerhound, GDTP T-0419
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Inventor 2010
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RE: Ordinate Dimensioning
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Ordinate Dimensioning
RE: Ordinate Dimensioning
Frank
RE: Ordinate Dimensioning
Matt Lorono, CSWP
Product Definition Specialist, DS SolidWorks Corp
Personal sites:
Lorono's SolidWorks Resources & SolidWorks Legion
RE: Ordinate Dimensioning
JP,
If the distance from Chicago to your home is 200+/-5 miles, then distance from your home to Chicago is...?
Checkers...
RE: Ordinate Dimensioning
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Ordinate Dimensioning
Your question turns it around, so you are changing the zero point to be my house. So it's not the same in terms of how the tolerance is envisioned. The numerical distance is the same (duh), but the phrasing of the question has implications!
I think that using ordinate dimensioning is seen as equivalent to the dimension origin symbol. Admittedly, that's not spelled out in the standard (and I'm usually the hardliner about following the letter of the law!).
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Ordinate Dimensioning
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Ordinate Dimensioning
Eather way should use this:
http:/
Actually this thread is pretty good example of confusion that happens when you don't use GD&T
RE: Ordinate Dimensioning
Eather way should use this:
http:/
Actually this thread is a good example of confusion that happens when not using GD&T.
RE: Ordinate Dimensioning
RE: Ordinate Dimensioning
I am east of Chicago. Don't try to track me down, guys. I won't be home.
And I certainly agree that this whole thread is an illstration of why GD&T should be used. I don't want to appear to defend a drawing practice that might be confusing.
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Ordinate Dimensioning
I tried to do this once, and everyone laughed at me. I wanted to apply a ± tolerance to a hole at my zero position.
Once again, GD&T positional tolerances solve the problem.
RE: Ordinate Dimensioning
It is spelled out in the standard. Ordinate dimension isn't called "ordinate" in Y14.5. It's called "Coordinate Dimensioning without dimension line". The 0 is only the baseline for the oridnate set. It is treated the same as baseline dimensioning or any other coordinate dimensioning scheme. It is not the same as the dimension origin symbol. Dimension origin symbol is used to specify that a tolerance is taken from on feature and not the other.
ISO used the same symbol with "running" dimensions, but it makes no statement (at least that I can find) that states the tolerance shall be taken from baseline only.
Matt Lorono, CSWP
Product Definition Specialist, DS SolidWorks Corp
Personal sites:
Lorono's SolidWorks Resources & SolidWorks Legion
RE: Ordinate Dimensioning
A hole 6" off the origin ±.005" is no different from an origin point off the hole ±.005". If you want to consider it as the origin has a tolerance in relation to the hole (as opposed to the other way around) that's very strange, but go for it. Just watch out for stacking tolerances.
RE: Ordinate Dimensioning
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: Ordinate Dimensioning
RE: Ordinate Dimensioning
The Y14.5 is very clear about this. Ordinate dims are nothing more than coordinate dimensions that don't have dimension lines on the drawing. They are treated the same as any other coordinate dimensions. The tolerance is applied to the dimension itself; the feature at either end can vary within that tolerance.
Even the Origin Symbol doesn't tolerance one end or the other. It simply applies the tolerance variation to the far end only. The baseline is treated as sort of a datum (datum rules from GD&T don't apply to it, but it is still the reference from which the dim originates, rather than having no preference if the symbol isn't used).
Matt Lorono, CSWP
Product Definition Specialist, DS SolidWorks Corp
Personal sites:
Lorono's SolidWorks Resources & SolidWorks Legion
RE: Ordinate Dimensioning
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
TecEase, Inc. www.tec-ease.com