【转帖】drafting of complex pipes

yang686526

drafting of complex pipes
i am trying to dimention pipes that are to be bent on a cnc bender and have troubles getting the true angle of the bend.  to get the true angle you need both legs of the bend on the plane of the paper.  if the pipe has multiple complex bends then is is very dificult to get both legs on the plane.  from the 3d software i can create a plane using the centerline vectors of the bend and then place a view using the created plane.  but i am finding this method to have a lot of resistance from the checker because i cannot explane the orientation of the view from the standard views.  is there a drafting standard for this type of problem, can i place a view that has no easy tracability to the standard 3 views?  what is the preferd method of drafing compex pipe/tube shapes?
add a bend table to the drawing with point coordinates of each bend.
chris
solidworks/pdmworks 08 1.1
autocad 06
there is already an xyz coordinate system on the draft for the cnc bender, but this doesn't help the guy who has to inspect the pipe.  i want to put down the dimension that he can measure with out getting out his calculator.
???
while it may take much thought, properly defining view orientation is important if the part is to be defined on paper.  it may take three or four projections to get a single view to dimension, and many drawing sheets to completely define the part.
think what drafters went through when descriptive geometry was the only way to accomplish this and count your blessings.
i realize that this isn't what you wanted, but have patience and think it out.
believe it if you need it or leave it if you dare.fff"> - robert hunter
i used to work in a shop that did complex marine exhaust pipes with short radii and double walls.  we dimensioned the location of both ends of each elbow or tube in regular coordinates, and put the included angle and radius of the elbows in the bill of materials.
this would not be of use to anyone programming a tube bender, but our radii were too short to bend anyway, and it worked okay for inspection.
mike halloran
pembroke pines, fl, usa
look at the example here:
check out this book, specifically page 42.
thank you for the comments so far, they have helped a lot.  is there any way to place a view on a drawing that is not a projection or auxillary view of an exsisting view?  can i defign or name the view so the reader knows where it comes from, or do all views have to have visual orientation to a standard 3-view?
at this point, i think you and the checker have to agree on just exactly who is going to be reading the drawing and for what reason.
mike halloran
pembroke pines, fl, usa
what you can and can't do with your cad program should be asked in the appropriate forum, since its not related to drafting in general.
"art without engineering is dreaming; engineering without art is calculating."
this is not a cad capability question but rather a drafting standard question.