"S" in a circle. It's no longer needed?
"S" in a circle. It's no longer needed?
(OP)
I know the answer already i believe but i have some people here that doubt me, even knowing i have the ASME standard. According to ASME Y14.5M-1994 the "S" in a circle is no longer need, correct??. "S" use to mean "regardless of feature size"
I'm assuming the ASME didn't add this back in, correct???
I'm assuming the ASME didn't add this back in, correct???
Solid Edge V20





RE: "S" in a circle. It's no longer needed?
Dave D.
www.qmsi.ca
RE: "S" in a circle. It's no longer needed?
Could anyone scan a copy of just the new MODIFYING SYMBOLS and post it? if it legal and all..:)
Solid Edge V20
RE: "S" in a circle. It's no longer needed?
SeasonLee
RE: "S" in a circle. It's no longer needed?
Solid Edge V20
RE: "S" in a circle. It's no longer needed?
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: "S" in a circle. It's no longer needed?
GO RED WINGS!!!!!!!!!!
Solid Edge V20
RE: "S" in a circle. It's no longer needed?
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: "S" in a circle. It's no longer needed?
The reason that it is no longer necessary is that the 1994 standard makes RFS the assumed value, instadd of MMC. So, it is actually a good idea to NOT use it, as it would create confusion as to which standard you are using and whether no symbols means MMC or RFS. If MMC is even suggested as default and your drawing is done to 1994, then you can be really screwed.
I would suggest that it is not correct to use circle S, especially if you are now invoking 2009 on that print.
And, the S was not "forgotten" in 2009. That comment suggesting this is extremely off-the-cuff. Every statement change in the standard is debated endlessly before its inclusion or exclusion.
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: "S" in a circle. It's no longer needed?
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: "S" in a circle. It's no longer needed?
Solid Edge V20
RE: "S" in a circle. It's no longer needed?
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: "S" in a circle. It's no longer needed?
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: "S" in a circle. It's no longer needed?
The '09 standard eliminated Rule #2(b), making it illegal to use the (S) modifier. I don't agree with this decision myself, but that's what the committee voted for.
Evan Janeshewski
Axymetrix Quality Engineering Inc.
www.axymetrix.ca
RE: "S" in a circle. It's no longer needed?
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: "S" in a circle. It's no longer needed?
Rule #2a is an alternative practice of Rule #2. Rule #2a states that, for a tolerance of position, RFS may be specified in feature control frames if desired and applicable. In this case, the RFS symbol would be the symbol from the 1982 version of Y14.5, please ref to the attached examples of Rule #2 and Rule #2a ( from Alex Krulikowski GD&T Workbook ).
Would you please advise where I can find out Rule #2b.
SeasonLee
RE: "S" in a circle. It's no longer needed?
http://sto
Chris
SolidWorks 08, CATIA V5
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion
RE: "S" in a circle. It's no longer needed?
I'll leave out the obvious Shakespeare joke here.
You're right, it's Rule #2a in the '94 standard. The section that it's in is 2.8(b) on page 28.
I had looked it up in the Former Practices appendix in the '09 standard, which says that Rule #2(b) has been eliminated. Looks like there's another typo in '09 to report.
Evan Janeshewski
Axymetrix Quality Engineering Inc.
www.axymetrix.ca
RE: "S" in a circle. It's no longer needed?
Once back to work tomorrow i'll have to get the ASME standard out and look up #2a
If true, thinking of not saying anything....
Solid Edge V20
RE: "S" in a circle. It's no longer needed?
Chris
SolidWorks 08, CATIA V5
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion
RE: "S" in a circle. It's no longer needed?
SeasonLee
RE: "S" in a circle. It's no longer needed?
When new programs come on board with 2009 as the contractural GD&T std, it will be interesting to see if they can deal with it.
RE: "S" in a circle. It's no longer needed?
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: "S" in a circle. It's no longer needed?
I guess he does listen to me once i awhile.....
Solid Edge V20
RE: "S" in a circle. It's no longer needed?
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: "S" in a circle. It's no longer needed?
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: "S" in a circle. It's no longer needed?
Just recently I told a designer to remove something from a drawing that was bad practice and he refused. Another good designer who was doing some part time checking saw the same drawing, made the same comment to him, and he changed it for that person.
So a full time checker's word is not valid, but a designer/part time checkers' word is? Makes me feel a little like Rodney Dangerfield.
RE: "S" in a circle. It's no longer needed?
Solid Edge V20
RE: "S" in a circle. It's no longer needed?
Powerhound, GDTP T-0419
Production Manager
Inventor 2009
Mastercam X3
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
RE: "S" in a circle. It's no longer needed?
RE: "S" in a circle. It's no longer needed?
RE: "S" in a circle. It's no longer needed?
That was our original arguement. That is why it was dropped in the first place, but our engineering management isn't buying it.
RE: "S" in a circle. It's no longer needed?
Powerhound, GDTP T-0419
Production Manager
Inventor 2009
Mastercam X3
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II
RE: "S" in a circle. It's no longer needed?
When training on the '94 version, I always recommend to students to put the (S) in the feature control frame even though it's an alternative practice. To me, the presence of the explicit symbol clearly shows that the designer really intended RFS as the condition. The "no modifier" implied condition leaves open the possibility that an (M) or (L) modifier was intended but accidentally omitted.
But now when I start training on the '09 version, I won't be able to recommend use of the explicit (S) because the practice has been outlawed.
Personally, I don't see the harm in giving the designer the option of using the explicit modifier instead of the implied condition. But there must be other reasons why the committee voted to remove that option. What do you guys think?
Evan Janeshewski
Axymetrix Quality Engineering Inc.
www.axymetrix.ca
RE: "S" in a circle. It's no longer needed?
Solid Edge V20
RE: "S" in a circle. It's no longer needed?
In 1982 this was modified to manadate the applicable modifier (MMC,RFS,LMC) for position and make RFS the default for other tolerances, dropping rule 2A to be more in-line with international practices.
Then in 1994, RFS became the default over MMC in a new rule (para. 2.8(a) to further be in-line with ISO and this is when circle S was removed. They kept the option, however, with 2.8(b)to satisfy those who would be confused and those that liked it (such as our friend Evan, and the management at my place).
So I see the total dropping of the circle S in the new 2009 standard as a further capitulation to ISO practices, which is OK, since it is an extension of rather than reversal of the current practice.
I don't agree with "belt + suspenders (braces)" approach that putting in the circle S tells everyone "Look, I really meant to do this. I didn't forget my circle M!
Follow the standard, agree nor not, for pity sake.