Most of the comments that Frank Sergent made regarding 3D printing used for production castings probably mean very little to most readers. And there's a good reason why: folks who are not "in" the field of 3D CAD and rapid prototyping aren't experienced with the headaches that come with this technology. Most likely, Frank is printing his parts in a wax material. His parts are probably part of a tree that contains many parts (which become cavities after applying 6 or 7 layers of refractory coating and subsequent firing to burn out the wax). Investment casting is the MOST expensive method of making metal parts. Conversely, die casting is the cheapest simply because the former requires a HUGE amount of labor while the latter requires very little labor (but a lot of production quantities to justify the tooling expense).
Kadee makes their living from their couplers. Their HO RTR cars and trucks are a sideline, from what I've been told but, nevertheless, they are top-notch just like their couplers. The cost to produce each multi-cavity coupler die cast mold can be in the 6-figures range (remember: there are 2 pieces to each coupler, plus subsequent manufacturing processes to create the trip pin, spring and assembly). I've had many email discussions with Sam at Kadee re: S scale items and his answer has always been the same: the market is too small and too splintered to justify a large investment. Unfortunately, he's right. Sergent is to be commended on sticking to his S scale offerings despite countless delays and production headaches. Rapid prototyping is NOT a cheap alternative to other manufacturing methods despite recent Yahoo list banterings (not S scale lists) about "affordable" desktop 3D printers. If someone wants to learn how to design in 3D, which is a VERY steep learning curve, then learn how rapid prototyping works (also steep), then fund numerous false-starts before finding the "right" process to fit your needs, then all I can say is "go for it". Oh, after that, keep in mind that you need to make a profit too. Jim King Smoky Mountain Model Works, Inc. Ph. (828) 777-5619 <www.smokymountainmodelworks.com>
