【转帖】drafting methods

yang686526

drafting methods
is it okay to dimension section views.
definitely, otherwise they would only be good for assembly drawings.
   you shouldn't dimension in an isometric view because it doesn't show true size and shape and you can't dimension to a "hidden" feature. cut views, section views, etc. are all okay as long as it is clear what the feature is that you are dimensioning (true size and shape).
you can find everything you need to know about section views in multi and secional view drawings asme/ansi y14.3.  it's a good buy.  i'm currently redesigning a high speed miniture mechanism and was looking at the drawings.  i found numerous mistakes: wrong projections, wrong callouts, dimensions to hidden lines and the granddaddy of them all a section view with hidden lines
best regards,
heckler
sr. mechanical engineer
sw2005 sp 5.0 & pro/e 2001
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never argue with an idiot. they'll bring you down to their level and beat you with experience every time.
it depends on which standard you are refering to, and whether you are using board drawings or cad drawings of solid models.  asme y14.41-2003 definitely allows dimensioning to axonometric views (which are similar to iso views) on the drawing.
section views are ok to dim. i agree, do not dim to hidden lines.
chris
systems analyst, i.s.
solidworks 06 4.1/pdmworks 06
autocad 06
palecactus
yes!
ok that's the short version.  
i prefer sections to use of hidden line most of the time, i thought it was in a standard somewhere that sections etc are preferable but i couldn't find it last time i looked.
aardvarkdw,
i'm with you on iso views but in my post the other day people seemed to think 14.41 might allow this.
ken
not only are sections preferable, but dimensioning to hidden lines is not a preferable method per y14.5.  para "dimensions should be shown in true profile and refer to visible outlines."
omitted in my previous post: para 1.4(c)
in some cases it is ok to dim to a "hidden" line, by drawing a broken out section, that makes the "hidden" line visible... but you should use this method discretely.
wes c.
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when they broke open molecules, they found they were only stuffed with atoms. but when they broke open atoms, they found them stuffed with explosions...
but then it is no longer hidden;) - that is a widely used method to get around hidden lines.