【转帖】gd t question weak definition

yang686526

gd & t question? weak definition??
what is wrong with the following drawing view??
i'm not sure what the intent is here, but i'll bite.
in this 2-dimensional view, it's difficult to tell what the features are that have position tolerances on them.  are we looking at bosses of different heights, or are there some gaps in there too?
the 6.40 +/- 0.15 dimension is a classic case of applying a plus/minus tolerance to a "non feature of size".  several features share the nominal 6.40 spacing, and some of them are non-opposed, so inspecting it would involve some guesswork and assumptions.
evan janeshewski
axymetrix quality engineering inc.
ryandias,
   i assume that you have more information on the other views, so i am not willing to point out missing details.  we cannot see where datums d and e are.
   the 6.40 dimension looks like it should be 2x 6.40.
   the watermark looks like part of the word "confidential".
   your object lines should be thicker than your dimension lines.   
   it looks like an electrical connector.  since we do not know what your requirements are, we cannot comment on the validity of your specifications.  if datums d and e are properly called up, i can interpret your drawing.
                       jhg
offhand, just about everything.
the min dims would seem inadequate.  not seen positional tol applied to ext line.  extension lines should not be interrupted with the fcf....  and more.
damn you guys are picky!!
thanks for the replies.
i should have given more direction to my question.
i was told that the gd&t position call-outs are "a weak definition."
unfortunately i was a bit embarassed, that i didn't know what he was saying explicitly.
now can anyone mention why he deems this use to be "weak"?
ryandias,
   you asked us to be picky!
   i would ask for a better definition than "weak".  maybe he thinks your tolerances could be made tighter.  maybe you used the wrong colour ink.  
                    jhg
where are "d" and "e"?
maybe "soft" would be a better term than "weak".  probably some yutz wants to see actual dimensions explicitly locating the features.  giving benefit of doubt for what is not seen, it appears the features are adequately defined.
you can go ahead and post more of the drawing now.  your secrets are not that impressive or important.
i'm pretty hesitant on posting a full page.  my initial conclusion as to why he said weak is because the positional tolerance is greater then the dimensional tolerance in one case.

ryandias,
   several of your prositional tolerances are tighter than your size tolerances.  so what?  there is nothing in asme y14.5m-1994 that says you cannot do this.
   what are you trying to do?  if your part is what i think it is, it must mate with another connector.  the mating features have to clear each other.  this is where i like to show nominal dimensions and zero positional error at mmc, although this is probably a bad idea for rp and any sort of casting or molding.
   you should be trying to call up the loosest tolerances possible.  
   do a tolerance stack up with the mating part, and see if there are any problems.
                               jhg
drawoh.
you are correct it is a connector.
it is a connector companies design.  i want no part in the design or responsiblity for its function.  the views shown are direct "copies" of the vendor drawing.  we have incorporated our own part with the connector spec'd from the customer.  
the supplier is now ripping appart the sections that show the vendor drawing details.  i am not sure of all the vendor drawing details, but have incorporated them as is (neither i or my seniors want to undertake connector design responsibilities).
i don't know where to start. i see a lot of problems... gd&t, drafting, etc.
chris
solidworks/pdmworks 08 3.1
autocad 08