【转帖】rue length call ou

yang686526

"true length" call out
is there a standard (or abreviation), to explicitly state that a dimension is the true length?
scenario:  i have a bent tube, with bends in more than one plane, ie compound bends.  i have my main views showing the entire tube, but my auxiliary views, which show certain sections of tube in their true view, are only partial, to save space.  i want to make sure the vendor knows that the length in that view is the true length.  it should be obvious from the direction the view is taken, but not knowing the vendor, i't like to "idiot proof" things as much as possible.  i'd also like to do this via some standard, if one exists, for the same reason.
is there such a standard, or accepted practice?  or should i just add the comment "true length" to the dimension?
thanks,
dave
-dave
everything should be designed as simple as possible, but not simpler.
i h ave seen it different ways.
you can show one view with isometric indicating all dimensions
or...
you would show your normal views. additional views would indicate if rotated (cw 45 deg, ccw 30 deg, etc) from a view.
thanks, that pdf is pretty handy.
-dave
everything should be designed as simple as possible, but not simpler.
i'm not sure the word "true" is appropriate. on a drawing, true is the default for projection ortho or aux views and should not be stated as "true" (redundant).  for pictorial views (such as iso's), a statement of "true" added to a drawing means that the entities being dimensioned are not true depictions in that view.
  
matt lorono
cad engineer/ecn analyst
silicon valley, ca
i've only seen "true" used for radii or diameters.
"art without engineering is dreaming; engineering without art is calculating."
i've seen and used "true" on orthographic views where the feature being dimensioned is not in the viewing plane, usually holes and radii.  granted, this is not best practice, but avoids defining odd view projections for the sake of one or two dimensions, and is supported for radii in y14.5-1994, para 1.8.2.3.  i'm not sure it's kosher for length dimensions.
believe it if you need it or leave it if you dare.fff"> - robert hunter

well, i decided that since the views are in the viewing plane, i'd leave off the "true length".  
thanks for the input.
-dave
-dave
everything should be designed as simple as possible, but not simpler.