【转帖】drawing philosophies 9help10

yang686526

drawing philosophies (help!)
please look at the attached print and tell me if this is legal, and if so, legal by what standard (asme y14.100-2004 is what we use).
this part has a locating fixture for a jig (see right hand view)... after locating it, we face it off (see left hand view).
these have been 2 different part numbers... when the left one is built off the right one.
recently i had an engineer come to me and suggest we could put both of these on one print using configurations (swx) ... just as you see in the attached print.
what do you guys think of putting these 2 parts on one print?  what is the official rule on having some views on a print not match up with other views (some of these views would not have the facing operation).  seems confusign to me.
are you talking about using "dash" numbers. this is often used for either left & right hand parts and for items that are basically similar but maybe there are several different lengths, y14.24-1999 has an example (fig 5) of a 'tabulated monodetail drawing.  it also talks about left/right hand (not in those terms) in section 3 (mainly a foot note).
however, it apears your left & right aren't just mirror images, that one has an extra feature (or lack there of) so i'd be cautious.
a good philosophy is "just because the cad software lets you do it doesn't make it right".
kenat, probably the least qualified checker you'll ever meet...
ok, i re-read your post and actually you aren't talking about quite what i thought you were.
i'm not sure i understand why you don't just have the finished part detailed.  i think i'd lean toward separate numbers as i certainly think your single drawing might be confusing.
kenat, probably the least qualified checker you'll ever meet...
i know what you're talking about.
i will clarify that this is not an application of length or handedness.
this example here shows a part that has undergone initial operations (view on the right)... then it either gets stocked or transported to a different machine to get the final operation (view on the left).  that's why we will have multiple part numbers and prints to reflect the life of this part as it makes it's way to a "finished" part.
i just don't like the idea of having a view of a part that doesn't match the other views.  it's confusing for inspection... or even for manufacturing the part (if i had to read and interpret this print).
thanks for your response kenat
kenat - in a perfect world we would have one part number and one finished part, unfortunately, we have different machines, different operations, stock needs... that force us to create multiple level parts that look like this:
a = unfinished (material is raw)
b = semifinished (material is "a")
c = finished (material is "b")
does that clarify?  thanks again
i've seen similar done once or twice but it never seemed very efficient etc. but you probably know what suits your needs better than i.
so you definitely need separate part numbers because of the stocking issue.
the question is whether you can have the different part numbers detailed on the same drawing then.  
you're effectively talking about a multidetail drawing per section 3.2 of asme y14.24-1999.  figure 6 is an example though i'm not clear how they identify which part is which number in that example.  the standard does caution against doing this unless you're sure the benefits outweigh the problems.
i suggest you take a look at 14.24, maybe some posters that have used these more than i can comment.
  
kenat, probably the least qualified checker you'll ever meet...
the only place we use dash numbers is for tooling assemblies.  each component is detailed on the same drawing and has its own dash number.  the completed assembly is the part number without a dash number.  i would caution against using dash numbers as you have described; it will probably cause more confusion than it's worth due to the mixture of operations involved.
when the people fear their government, there is tyranny; when the government fears the people, there is liberty.fff"> - thomas jefferson

i always have separate part numbers and drawings for parts.
but, for tooling/fixtures the parts that make up the tool are all stamped with the same tool number. therefore, i create multiple sheets and add all parts as dash numbers. when i created military/aerospace designs, this was a requirement for us.
chris
solidworks/pdmworks 08 3.1
autocad 06/08
sounds like you need a make-from drawing.  i suggest that the items should be two different part numbers, each on their own drawing.  configurations with sw models is fine, but don't use one drawing for both configurations if they are really different parts.  just some thoughts.
matt lorono
cad engineer/ecn analyst
silicon valley, ca
anything having to with "dash numbers" or anything more sophisticated than "dumb numbers" won't work with us and our part number philosophy (everything is given a dumb 6 digit number).
so, none of those are options
multiple drawing sheets gets a little scary (if it's for different parts).  in other words, i wouldn't want to bury unique parts inside other sheets of a drawing.
is it just me, or is "one part.. one drawing" out of date?  i always thought that philosophy was very robust and prudent
also - i've looked thru the asme standard and i'm not having any luck locating a defitive answer to my question (via a standard such as the asme standard).
are you guys aware of drawing standard that discusses multiple parts on a single print?