composite position tolerance (in composite feature control frame vs separate feature control frame)
composite position tolerance (in composite feature control frame vs separate feature control frame)
(OP)
Hi,
Greetings!
can somebody explain clearly what is the difference between composite position tolerance in composite feature control frame and composite position tolerance in separate feature control frame(see attached image).
i didn't get much understanding from standard.
Greetings!
can somebody explain clearly what is the difference between composite position tolerance in composite feature control frame and composite position tolerance in separate feature control frame(see attached image).
i didn't get much understanding from standard.






RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
See this
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
Here is just one example:
https://www.youtube.com/watch?v=GFgoctqNkRo
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
that helped a lot :)
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
can you please suggest some good books for learning the 'GD&T' and stack up.
thanks.
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
--------------
-the ASME standard (cons of this already discussed)
-the Cogorno text book (many, many errors in this book but still good for the beginner)
-the Cogorno instructor's materials (3 tests w/ answers)
-the Meadows text book (I would read Cogorno first)
-the Meadows workbook (read his textbook first)
-Tec-Ease vids on youtube
-this forum
-consultant brought in to discuss application of GD&T to the parts my company makes
-------------
There are many more books and resources available but I have not read them, so I have no opinion.
If you buy the Cogorno book I can send you a list of corrections that I have compiled.
I am just beginning to study stack.
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
I'd really appreciate it if you made your Cogorno book error list available to us here. I have only the standard and a pile of free resources I've gathered, but the Cogorno book is at the top of my list because I found his newsletters to be very helpful (http://www.ttc-cogorno.com/Newsletters/index.htm).
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
Please note that I have not made corrections to the "chapter review" (fill in the blank) sections of the book. There may be errors in these sections also. I have only noted the errors in the text of the chapters and the end of chapter problems. Also my list is not complete. I find more errors every time I reread this book.
One last thing, some of the text that I draw attention to is not necessarily incorrect but some of the beginning students at my work were confused by the author's wording so I offered alternative wording (hopefully not alternative facts...). This is only in an effort to make clear the intention of the author, as I interpreted it, for my coworkers.
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
To picture Cogorno's example, take fig. 7-26 from the 2009 standard and add A as primary datum feature reference to the position callout for c'bores.
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
If the design intent is to have each c'bore located from its respective hole but oriented w.r.t. datum A then I would agree that [A] [C@MMB] is correct.
Thoughts?
RE: composite position tolerance (in composite feature control frame vs separate feature control frame)
Whenever possible, function / design intent should be the main driver in choosing dimensioning and tolerancing schemes.