XPost: sci.space.policy, sci.physics, sci.electronics.design   
      
   In sci.physics Jeff Findley  wrote:   
   > In article , jimp@specsol.spam.sux.com   
   > says...   
   >> 3D printing requires special raw stock manufactured just for 3D printing   
   >> no matter what the print material is.   
   >>   
   >> 3D printing is slow and expensive compared to any other method of making   
   >> parts so only become economical if the part in question is so complex that   
   >> 3D printing it is cheaper than any other method.   
   >   
   > Actually if the 3D printed part replaces many other parts (e.g.   
   > SuperDraco engines) then it's faster to print than it is to manufacture   
   > and assemble all those other parts.  But that does fall under your "so   
   > complex" exception because in that case it is cheaper to print than try   
   > to use other manufacturing techniques.   
   >   
   > In aerospace, think things like liquid fueled rocket engine combustion   
   > chambers with lots of tiny internal cooling passages.  Those are a   
   > p.i.t.a. to make using conventional manufacturing techniques, but a   
   > breeze to 3D print.   
      
   And the total market for such things is a tiny fraction of all things   
   manufactured, or even of all 4 slice toasters manufactured.   
      
   >> The cost and speed of 3D printing will obviously never match that of   
   >> stamping out sheet metal, casting, or NC machining.   
   >   
   > For "trivial" parts, that is true.  I installed a new garage door at   
   > home a few weeks ago.  Lots of stamped sheet metal parts there, even the   
   > hinges.   
      
   My estimate is that for all things manufactured parts that can be made   
   cheaper and faster by conventional means amount to about 99.99%.   
      
   >> > But progress is being made in the field.  GE is working on producing a   
   >> > 3D printer capable of printing 1 meter x 1 meter x 1 meter parts.  This   
   >> > is coming from its aircraft engine division.  3D printing is a very hot   
   >> > topic these days.   
   >>   
   >> Yes, for very complex parts that would otherwise have to be made in   
   >> pieces then somehow assempled.   
   >   
   > Exactly.   
   >   
   > Also, the other option that 3D printing opens up is more shape optimized   
   > parts.  These things are optimized so that "useless" mass is simply gone   
   > from the design.  They tend to look "organic" rather than "machined" due   
   > to their complex shapes.  I've heard this called "light-weighting" parts   
   > from management types.   
      
   And about the only place where weight matters that much is in things   
   that fly and in that case useless mass is already gone from the design   
   without the expense of 3D printing.   
      
   Have you ever looked at the interior structures of an aircraft?   
      
   3D printing is, and always will be, a niche manufacturing method.   
      
   Handy at times, but certainly not a world changer.   
      
      
   > Jeff   
      
   --   
   Jim Pennino   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)