Combining Position and Perpendicular

[cjccmc]

I have a design with a pattern of 12 pilot holes in a rectangular block. Usual datums of A being the flat bottom, B one edge and C the other edge at 90 deg. I can be generous on the placement of each hole both wrt to ABC and dimension between holes. But I do need each hole perpendicular .001 dia to A.
We use the 1994 version of Y14.5 and looking thru it all the true position composite blocks say that that the second line (related to datum A only) controls hole to hole tolerance in addition to perpendicularity to A. I do not want to force .001 tolerance hole to hole so is there a way to call this out legally?
My thought is to use a single line position block then add a a perpendiclar frame below it that would look like this:
12X dia .125 +.003 -.000
pos/dia .020/A/B/C/
perpendicular/ dia .001/A

Intent of above seems clear but I can find no examples in 14.5 that show this. Is it legit?

 

[bxbzq]

Yes, it is legal.

 

[CheckerHater]

You are absolutely correct.
Unfortunately you mentioned Y14.5-1994; 2009 version of the standard shows your case on Fig. 6-14 and 6-15

 

[pmarc]

cjccmc,
Yes, your approach is a way to go (if you still need another confirmation).

 

[cjccmc]

Thanks for your replies.

So my understanding is that Y14.5-1994 does allow this approach even tho they show no such examples.

 

[KENAT]

Yeah that's my understanding.

Always keep in mind paragraph 1.1.4. As much as we all like pretty pictures it's the text that really matters.;-)

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[IRstuff]

I think 14.5-1994 shows an example in Figure 4-2

TTFN
faq731-376

 

[Belanger]

No -- not Fig. 4-2.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

http://www.gdtseminars.com