Difficult to obtain or expensive to make loco parts - possible solution

3d metal 'printing' technology could be a solution accord to Popular Mechanics:

http://www.popularmechanics.com/cars/technology/a25298/metal-printing-will-save-any-old-machine/

Article even explicitly refers to 'early steam engine' parts.

 

I looked at this a few years ago and it was "very" expensive, OK for the aerospace industry but not for us amateurs, however I'm sure costs will come down in time.

Dave

 

A volunteer at the Isle of Wight Steam Railway is currently experimenting with 3D printing light fittings for our coaches.

 

Good for aesthetic parts yes.

For stressed components 3D AM still has a ways to go to compete £ for £ with conventional, especially considering how CNC machining quotes continue to fall across the board.

Additionally, verifying chemical and material properties for 3D AM is not as straight forwards as it is for off the mill bars/billets/sheets, not to mention the size constrains.

That being said, 3D AM is happening, its only a matter of time before it starts competing £ for £ with conventional.

 

For smaller complex parts it may well be worth looking at to make patterns for castings.
Baldric

 

We used a firm that printed a pattern in wax to which was than used in lost wax casting process.