Holding multiple surfaces parallel within 1 common tolerance zone 2

[SpaciouS]

How do you call-out Parallelism over multiple surfaces that are controlled within 1 common tolerance zone.

Can you simply call-out "x surfaces" under a Parallelism FCF and it's understood that all indicating surfaces are controlled simultaneously (similar to Flatness of multiple surfaces defined by a Profile FCF with such "x surface" notation?

Or would that indicate separate tolerance zones per individual surface?

Or, since I have never seen that example in any ASME standards, is that notation not appropriate when using Parallelism?

Is so, can I simply use Profile instead of Parallelism while referencing a datum and adding "x surfaces" beneath the FCF?

Or is it something else?

Thanks,
Sean

 

[ptruitt]

Dean's response to Pmarc got my attention:

"Yes, I think two single segment feature control frames with position or profile could replace composite feature control frames. They're almost equal, except for how simultaneous requirements works (with "SIM REQT" being required to tie together patterns that are toleranced with separate composite feature control frames... no such need with a set of single segment feature control frames). Customized DRFs are better since they more explicitly state what they mean than composite FCFs do, and the method is also more flexible/powerful since even rotational degrees of freedom constraint can be selectively specified using the customized method... I will create a couple of examples and ask in a new topic what others think of setting aside composite in favor of customized. It makes sense to introduce customized drfs before composite would be set aside, but I don't know what is best with regard to the overlap time, when both are available in the standard."

I am wondering how likely to show up in Y14.5-Next. Does anyone know?

I look forward to the topic you plan to post, Dean. 'Thanks', in advance.


Peter Truitt
Minnesota

 

[DeanD3W]

Hi Peter,
I will put some examples together and post my question about what others think of customized DRF tolerances being used in place of composite feature control frames, but it may be another 7 weeks or so until I get that done. Spare minutes between now and the end June will be hard for me to find.

Dean

http://www.d3w-engineering.com