I called Barry this morning to discuss the strength and and resilience of the 3d printing. I guess as parts become unavailable this is where we are heading. His response as follows:
Hi Andrew.
Further to our discussion around replacing the failed bakelite parts with 3D-printed metal:
RAM3D in NZ (
www.ram3D.co.nz ) manufacture production parts in full-strength metal alloys.
As-printed the material is fully-dense (see attached microstructure of our stainless steel) and the same strength as the same material purchased "off the shelf" in bar or plate form. Our material properties are as per the table attached.
We print 3 tensile test bars with every batch of product produced, and no parts go out the door until the tensile test results are in.
With 10 years of continuous data we have the world's longest-running dataset in this area by many years.
We manufacture production parts for almost every industry imaginable, including defence, aerospace, space, marine, land transport, food production, construction, agriculture and a great many more.
Also attached is a micro showing typical faults found in poor quality 'off the shelf' metals that many manufacturers never test for and hence never know the faults are in there. We conduct a great many failure investigations in our metallurgical laboratory and have a wealth of knowledge and experience in the area of strengths and qualities of materials.
Regarding 3D-printing of metals there is a lot of hype and general lack of knowledge about what is good quality and what is not. Any process that uses a metal powder mixed with a binder, and subsequent 'debinding' and 'sintering' in furnaces will not produce a full-strength reliable part. The sintered structure is not fully dense and is full of stress-raisers.
In order to be fully dense, full-strength and reliable a 3D-printed metal part must be made from pure metal powder (not mixed with a binder), and it must be fully melted solid in the printing process.
RAM3D's parts are solid metal as they come out of the printer. Our clients weld them, machine them, process them through any process that 'off the shelf' metals can be processed through - but usually with much better results as they do not have the flaws inherent in 'off the shelf' metals.
Industry, manufacturers and inventors are slowly taking-up the technology as they learn of it. Those who do usually leap-frog their competition in a big way as 3D-printing allows a product to be made to be the most functional it possibly can be - unrestricted by traditional methods of manufacture or material availability that usually restrict the functionality of a design.
As well as the caution about sintered metal parts, another big caution is for people who have enough money to buy a 'proper' metal 3D printer: You simply cannot buy a printer, add powder, press the button and get usable parts you can rely on. There is so very much more to it than that. You need some very special equipment and very special people skilled in metallurgy and design to make good parts. And you need full access to and understanding of laser parameters in order to get the machine working in a manner that will enable you to live long enough to see a good result. You don't buy a foundry and heat treatment shop because you want to make a few castings. Or buy a forging and heat treatment shop because you need a few forgings. You go to the experts who have invested many millions and many years learning. Unfortunately there are quite a few people making this mistake, with 2 bankruptcies so far in Australia as a direct result of uninformed leaping into this area. Worse still is uninformed, inexperienced and unknowledgeable operators making crappy product that gives the technology a bad name.
Buyers venturing into the technology should ask for tensile test results for their product batch.
Also attached is an article for an industry magazine that gives a fuller insight into additive manufacturing of metals. Unfortunately our best stories and product pics are restricted from publication by strict confidentiality arrangements.
I encourage anyone interested in learning more about the technology to contact me directly.
Regards, Barry
Barry Robinson
E barry@ram3d.co.nz
M +64 (0)27 286 4722
A 50 Paerangi Place
Tauriko Business Park, Tauranga 3171
PO Box No 16064, Tauranga 3147
F facebook.com/ram3dprinting
www.ram3D.co.nz 
