Free State Requirement for a dim without a FCF?
Free State Requirement for a dim without a FCF?
(OP)
I have a part where the engineer wants two things:
1) Datum feature B @ .550 +.030 / -.010 shall be measured in the free state (Default according to .5-2009 I think)
2) All other features apply while the aforementioned feature is in the restrained state.
What's the best way to indicate this? I thought that a flag note stating that "UNLESS OTHERWISE SPECIFIED, ALL REQUIREMENTS
APPLY TO THE PART WHILE DIMENSION INDICATED IS IN THE RESTRAINED STATE" appended to the dimension that should be first qualified in the free state. How to indicate that this dim is to be verified in a free state though is uncertain... mainly because, like I said, all examples of free state symbols are used in a FCF. Please see the attached image and let me know what you think. Thanks!
1) Datum feature B @ .550 +.030 / -.010 shall be measured in the free state (Default according to .5-2009 I think)
2) All other features apply while the aforementioned feature is in the restrained state.
What's the best way to indicate this? I thought that a flag note stating that "UNLESS OTHERWISE SPECIFIED, ALL REQUIREMENTS
APPLY TO THE PART WHILE DIMENSION INDICATED IS IN THE RESTRAINED STATE" appended to the dimension that should be first qualified in the free state. How to indicate that this dim is to be verified in a free state though is uncertain... mainly because, like I said, all examples of free state symbols are used in a FCF. Please see the attached image and let me know what you think. Thanks!
I'm not a vegetarian because I dislike meat... I'm a vegetarian because I HATE plants!!





RE: Free State Requirement for a dim without a FCF?
“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV
RE: Free State Requirement for a dim without a FCF?
Thank you ewh.
I'm not a vegetarian because I dislike meat... I'm a vegetarian because I HATE plants!!
RE: Free State Requirement for a dim without a FCF?
The problem with placing the flag note at the dimension is that it contadicts the purpose of the note, which is supposed to apply everywhere except at that dimension (which is why I suggested adding an additional flag note, specific to that dimension). Simply appending the dimension with "FREE STATE" (not in parenthesis, as it would not be reference) should suffice.
Other viewpoints welcome!
“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV
RE: Free State Requirement for a dim without a FCF?
Also, it may not be possible to fixture the flanges to the specified dimension. They are not going to magically float into position. They will bend and be at odd angles.
RE: Free State Requirement for a dim without a FCF?
2. (with flag symbol) THIS DIMENSION TO BE VERIFIED IN FREE STATE
RE: Free State Requirement for a dim without a FCF?
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RE: Free State Requirement for a dim without a FCF?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Free State Requirement for a dim without a FCF?
“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV
RE: Free State Requirement for a dim without a FCF?
According to ASME Y14.5-2009 Para. 4.20 "To invoke a restrained condition, a note is specified or referenced on the drawing defining the specific requirements"
Accompanying Fig 4-42 shows note referencing Work Instruction. So,... yes.
RE: Free State Requirement for a dim without a FCF?
However I have some questions related to the concept of restraining of this particular part. Here are just 3 of them:
1. Will it really be a solid restraint if B is referenced at MMB (in position and profile callouts)?
2. What is MMB size for B referenced in profile FCF? In that callout B is referenced as secondary datum feature, but a geometric relationship between feature B and datum A is missing.
3. Why B is referenced RMB in perpendicularity callout for datum feature C?
RE: Free State Requirement for a dim without a FCF?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Free State Requirement for a dim without a FCF?
Sorry if it wasn't clear.
The book says that you may reference external document as work instruction, explaining in detail how exactly to hold the part down.
Also, on the drawing you provide as many datum targets as you want to make it happen.
I guess that counts as "defined on the drawing".
OP's drawing has a note, and some sort of WI right on it but lacking some detail about how DOFs are to be constrained like pmarc noticed; so some work should be done in that direction.
So, yes, it should be defined on the drawing as the standard suggests.
RE: Free State Requirement for a dim without a FCF?
pmarc, hello, thanks for the questions... I'm not quite sure how to answer those questions just yet, but if you've got any ideas I'd be happy to help. I'm studying and learning myself, and probably will know more about all of this than the product engineer when all is said and done. However, it's my guess that he's going to tell me that this part is already done like this in-house and, in typical fashion, the drawing is simply trying to catch up with the process already in place.
What I know for certain is this:
1) Datum feature B is to be validated in the free state to the tolerances specified (+.030/-.010)
2) Part is to be restrained around / thru or with datum feature B (how is not something I know at the moment)
3) All other requirements should be validated after the part is slipped over the roughly rectangular bar and clamped.
I'm going to work on this and get back to you guys... Thanks very much for the assistance.
I'm not a vegetarian because I dislike meat... I'm a vegetarian because I HATE plants!!