General Surface Profile in a Note

[jasoncwells]

Do you guys feel like it is appropriate to place a general surface profile tolerance in a general note? The concern that I have is that you don't have a leader line to apply the all-over symbol, nor is it easy to add the text "all over" under the feature control frame within the text notes. So this is what I came up with. (forgive the non-cad formatting) The primary question is, am I missing something that makes this implementation of a general tolerance a "fatal flaw?"

4. UNLESS OTHERWISE SPECIFIED, THE GENERAL TOLERANCE IS ⌓0.5ABC ALL OVER.​

I've been through quite a bit of this forum looking at the various opinions on general surface profile tolerances. I have ASME Y14.5 if you have a reference that I missed. I think the idea is pretty slick. I especially like doing away with the default tolerance block with significant decimal places. (Metric with no trailing zeros, anyone?)

Perhaps I should simply forego the note and attach the feature control frame to one of my drawing views. I expect that a machinist would look at my title block with no tolerance block and then look at notes. I kind of like notes to establish "policy" for an entire drawing.

This would be my first drawing done for personal use, hence no corporate guidance to follow. I'm writing my own rules.

Thanks to all for your contributions throughout the years. You've done a tremendous service to engineers world wide. (esp KENAT, CheckerHater, drawoh, Sykes and others)

Regards,
Jason C. Wells

 

[CheckerHater]

It is perfectly fine to use text note to clarify your requirement when symbology alone doesn't seem to do the trick. So, no "fatal flaw".

Using Profile "all over" as general requirement was mentioned on this forum and seems to be acceptable. (Please note that if you reference your control to A|B|C, then A, B and C should be shown somewhere on the drawing.)

Using FCF is also appropriate (see enclosed picture).

You notice "drawing done for personal use"; do you "personally" also have the means to measure your Profile in reasonable way?

"doing away with the default tolerance block with significant decimal places" is another "larger than life" topic bringing in heated discussions on this forum.

And question that should probably be asked first: are you operating under ASME or ISO framework?

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[jasoncwells]

I think I've read all the hot topics you mention. I've always thought that the default tolerance block causes more problems than it solves. Surface profile all-over is just too powerful to ignore.

The only critical feature on my part is the threads and I will buy gauges for those. The tolerance on threads falls under the "UOS" rubric (e.g. UNC-2B, ISO 6g).

Thanks for attaching the picture. Perhaps specifying the all-over surface profile in a drawing view is more clear. Clarity being the benchmark for all drafting decisions. Since I haven't incurred a fatal flaw, I'll just have to decide. Thanks!

 

[pylfrm]

jasoncwells,

The "UNLESS OTHERWISE SPECIFIED" portion of your proposed note might cause trouble.

The following threads (and probably others) contain some extended discussion:
thread1103-415111
thread1103-410353
thread1103-409569


pylfrm

 

[jasoncwells]

I read the first link before I came here. I eventually concluded that CheckerHater and JNieman had the most salient comments. The best example of the meaning of UOS was a default surface roughness with a local specification of surface roughness. I think a default surface profile vs a local surface profile is interpreted in precisely the same fashion.

I believe a default surface profile UOS will serve its purpose for 90% of features I need. If there is unclarity with defaults, then it's my job to clarify. Ultimately, 8.3.1.6 says UOS. So adding UOS to a note is repetitive. I will probably delete UOS from the note for that reason.

Regards,
Jason