From: none@none.com99   
      
   On 12/7/2025 3:02 PM, Jim Wilkins wrote:   
   > "Bob La Londe"  wrote in message news:10h4d93$3jrfc$1@dont-email.me...   
   >   
   > Parts where the raw material cost is.  You need a bronze bushing.   
   > Bronze is expensive.  You can usually buy a bronze bushing cheaper than   
   > the raw stock to machine one.  If you are setup for it, and have been   
   > saving scrap you might be able to cast a bronze blank and then finish to   
   > spec, but generally the raw material is expensive.  If a usable bushing   
   > is already available its probably cheaper.  How about 3D printed bronze?   
   >   You might make the argument that, "Sure, that's great if you can stock   
   > 10 grand worth of bronze powder,and you already have a quarter million   
   > dollar laser sintering 3D printer.  The part is cheap, but the barrier   
   > to entry is quite high.  No.  There are filaments that can be printed   
   > (according to the manufacturer) on the same printers as PLA as easily as   
   > PLA.  I can only assume they mean with a hardened steel or carbide   
   > nozzle.  At this point I am falling back on sales propaganda, but it   
   > might have some potential.   The thing is its not the price of PLA.  A   
   > 1/2 kg spool of aluminum filament is over two hundred bucks.  Amazingly   
   > a 1/2 KG spool of bronze filament is a little less (not much).  Still   
   > its expensive, and to finish with a full metal part you have cook it in   
   > a furnace after printing to burn off the binder.  It sounds like a   
   > compromise part, but maybe there is something there.  I'm leaning   
   > towards probably not.  If I already have a furnace (I do) I think it   
   > would still be faster and cheaper to cast a blank and machine to spec.   
   > There may be something there, but I am sure the nuance escapes me.   
   >   
   > ------------------------   
   > Interesting but not yet useful for me.   
   > https://thevirtualfoundry.com/debind-sinter/?   
   >   
   > I watch what 3D has made to learn to think in its design terms, as I now   
   > think and design in terms of what my lathe and mill can (or can't) do. I   
   > was introduced to 3D printing of ABS at Segway 20 years ago and saw that   
   > it isn't strong enough for stressed parts of moving machinery, the sort   
   > of thing I may have to make or repair. I've seen some impressive recent   
   > 3D work at a Maker Space but not enough to tempt me to join.   
   >   
      
   I find most things machine faster out of better materials, but for   
   "additive" manufacturing I would like to be able to turn my scrap into   
   some form of usable raw stock again.  Foundry work.   
      
   I found a use case for some supplemental black smithing.  You can argue   
   that blacksmithing is both additive and subtractive manufacturing.  I   
   made a set of wrenches a while back using normal 2.5D machining specific   
   to some collet chuck tool holders I use everyday.  I managed to   
   partially mangle one end of one of the wrenches.  Its 4140HT, and I   
   figured it would be strong enough before it deformed.  It would have   
   been, but I let it slip.  I had cut deep enough for a second wrench, so   
   I just sliced a wrench off the stock.  However, the old wrench could   
   have been fixed a little faster by taking a step back in time.  I set it   
   out back on the bench near where I use the forge, and the next time I   
   fireup the forge I'll deform it a little further, and just machine out   
   the working surfaces that hold the tool holder.  Then I can heat treat   
   it like I should have the first time around.  While I did already have a   
   2nd wrench 90% machined if I didn't it would certainly have been faster   
   to reforge the mangled wrench than to make a new one from raw stock.   
      
   So far none of these thoughts have given me an epiphany about 3D   
   printing, but thinking about them has started to change how I think   
   about other processes.   
      
      
   --   
   Bob La Londe   
   CNC Molds N Stuff   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)