The goal of Project FabMX is to design and build an affordable, open-hardware 3d printer capable of producing metal objects.
FabMX is part of MakerTools.
The Process
We want to build a "metal pellet fused deposition modelling" system. What does that mean? The material to be used is MIM (metal injection molding) feedstock. This is a metal powder / plastic mixture with a very high percentage of metal (>95%) and can be bought in the form of pellets. In a conventional MIM procress, these pellets will be heated up until the plastic (a thermoplastic) gets soft and then gets pressed into a mold that gives the object its shape, just like with (non-metal) injection molding.
To get a metal object, further processing steps are needed:
- First the plastic has to be removed from the "green" part, this is called "debinding". There are several debinding systems, usually this is done thermically (in a debinding oven) or chemically, e.g. by putting the part in an acetone bath.
- The result of the debinding step is a very brittle "brown" part. This now has to be sintered in a sintering oven. The temperature needed depends on the used metal, for stainless steel it is around 1300°C.
To turn this process into one suitable for 3d printing, the first step (injection molding) is replaced by an FDM/FFF style 3d printer, but one with a pellet extruder suited for taking MIM feedstock. The resulting 3d printed "green" parts are then debindered and sintered just like in metal injection molding.
Why?
Before Adrian Bower started his RepRap project, you couldn't buy a 3d printer for under 20.000 Euros/dollars. But his project changed everything. He designed a 3d printer that anyone (with a 3d printer) could build and published all the plans under an open-source licence. Enthusiasts around the world picked up the idea, built their own machines and helped to improve the design. Soon you could buy kits by companies like Makerbot or Ultimaker, and today you can get ready-to-be-used open-hardware machines from e.g. Prusa, Lulzbot or BCN3D. From Asia you now can get 3d printer for as low as 200 dollars.
This means that the price for a 3d printer is now just 1% of what it was roughly 10 years ago.
For fablabs, makerspaces, startups and interested hobbyists this changed a lot: suddenly they got access to state-of-the-art production technology, that was only available to large firms or universities before. They now could produce their own custom parts, at a very low price. This opened up a lot of new possibilities. Just have a look at what people upload to thingiverse and ask yourself if that would have been possible without the access to a 3d printer.
But these 3d printers all have a big drawback: plastics only.
While the evolution of FFF 3d printers (and SLA/DLP resin printers) went on at an amazing speed, metal 3d printing technology is still in a "pre-RepRap stage": too expensive, only for the big players. The makers are left behind. This situation motivated us to start an open-hardware project, with which we hope to repeat (or should I say "replicate" 
) the RepRap story in the domain of metal 3d printing. At least a little. I hope some of you come with us on this amazing journey!
