Correct or not? And how to inspect?
Correct or not? And how to inspect?
(OP)
Are the parallelism calouts correct in Y14.5? Also how to inspect these orientation callouts at MMC?
Thank you
Gabi
Thank you
Gabi
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Correct or not? And how to inspect?
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RE: Correct or not? And how to inspect?
Parallelism as surface control is not using L or M modifiers.
To control parallelism of derived middle plane,
a) controls must be attached to appropriate FOS dimensions.
b) FOS must look like FOS (it may be argued if 1.000 dimension represents FOS of not).
So, better job could be done to control parallelism of these particular features.
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Correct or not? And how to inspect?
I know that flatness will control DMPF, but what about the parallelism? How to relate DMPF with the required parallelism?
My assessment:
You derive the median plane from the surface, there is no way that the DMP flatness could ever be greater than the surface flatness.
* flatness controls DMP (derived median plane) flatness, but DMP flatness does not control surface flatness. As long as the out-of-flatness of the surface is symmetrical, the DMP stays flat.
* specifying DMP flatness, the value in the feature control frame can be less than, equal to, or greater than the total size tolerance -- whatever is functional.
My follow up questions are above.
RE: Correct or not? And how to inspect?
I think you are comparing apples to oranges here.
Flatness cannot control parallelism. There is no relation.
Maybe you could chose different wording for your question, or, better yet, provide a little sketch.
Right now it's a bit confusing.
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Correct or not? And how to inspect?
If not, I will stand corrected.
Please advise and sorry for the confusion.
RE: Correct or not? And how to inspect?
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Correct or not? And how to inspect?
Just for academic purpose only and additional challenge (since the OP question has been answered)
So, how would you change the parallelism requirement to DMPF and get the same mathematical scheme (as the parallelism) ? I understand that the flatness could not control parallelism, but since the surface it is a regular FOS probably “some adjustments” can be made to make these callouts equivalent.
There is such or equivalency?
RE: Correct or not? And how to inspect?
And providing that Rule 1 is in action, you could shrink size tolerance until both flatness and parallelism satisfy your demand.
Unless you are trying to ask something else?
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Correct or not? And how to inspect?
John Acosta, GDTP Senior Level
Manufacturing Engineering Tech
RE: Correct or not? And how to inspect?
Just for academic purpose only and additional challenge (since the OP question has been answered)
RE: Correct or not? And how to inspect?
John Acosta, GDTP Senior Level
Manufacturing Engineering Tech
RE: Correct or not? And how to inspect?
What is 'Derived Center Plane'? 😉
RE: Correct or not? And how to inspect?
RE: Correct or not? And how to inspect?
Tunalover
RE: Correct or not? And how to inspect?
RE: Correct or not? And how to inspect?
May I ask you: What is the difference between: “parallelism of derived middle plane” and “derived median plane flatness”
Will DMPF control parallelism in the case shown?
Thank you
Gabi
RE: Correct or not? And how to inspect?
And no,flatness will not control parallelism.
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Correct or not? And how to inspect?
My questions for you would be:
What about DMPF in combo with the size dimension for regular features of size, will that indirect control the parallelism?
RE: Correct or not? And how to inspect?
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Correct or not? And how to inspect?
It is hard for me to believe that DMPF combined with the size dimension would have no effect over the maximum parallelism allowed for the feature of size.
In other words, lets say along with the size dimension a DMPF callout is added such as DMPF in .010 at MMC. The question (could be a GDTP exam question? ): what would be maximum parallelism allowed between shown surfaces (I am talking about FOS surfaces, .650 size).
RE: Correct or not? And how to inspect?
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Correct or not? And how to inspect?
If rule#1 is not (since in my example I have added DMLF) then how is the parallelism controlled direct or indirect?
That is my dilemma.
RE: Correct or not? And how to inspect?
RE: Correct or not? And how to inspect?
Why exactly you want to control parallelism without using parallelism control?
Doesn't make lot of sense even from purely academic point.
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Correct or not? And how to inspect?
To learn more about all of these controls/callouts. And to avoid redundant callouts on the drawings.
To see and understand the "unintended consequences" of some GD&T callouts. --direct versus indirect relationship between features---
RE: Correct or not? And how to inspect?
RE: Correct or not? And how to inspect?
In my hypothetical case I don't have a datum feature (only DMPF and size dimension). Remember: the OP question has been answered and I am building additional or revised constrains and /or questions based on his original thread.
Also what is that "center plane"? (maybe wrong nomenclature) This question has been asked before.
RE: Correct or not? And how to inspect?