Laser Cutter as Metal 3D Printer?
I have wondered for a while if one these increasingly cheap CO2 laser cutters could be used to sinter metal powders and thus build a metal 3D printer. These machines are commercially called Direct Metal Laser Sintering, I believe.
Technically, the CO2 laser is not at the best wavelength for this as can be seen here:
But CO2 lasers can be had relatively cheaply nowadays. I see units like this 60W one on eBay for less than $2000 now:
Compared to buying some surplus YAG laser, these have the added bonus that almost the whole sintering system would be complete. The 'only' thing left to do would be the powder hopper.
I have access to a 60 Watt CO2 laser cutter very similar to the one shown above, and so I decided to run some tests to see about the feasibility of making a DMLS system from that.
I 3D printed a plastic tray to hold the powder and filled it with 325 mesh 316 stainless powder. After leveling the powder, I set the laser focus to the top surface. Then, I set the printer to full power and full speed to print a 1x1 cm square:
Here is a video of that first attempt:
Some of the powder got blown around by the air purge that protects the focusing lens, but a small square clearly got fused.
I tried again, lowering the speed to 11%, but keeping the power at 100%:
This time, the sample did come out a little stronger, but it was hot enough to melt the plastic tray below.
Here a video of the second run:
All in all this is very promising! It sure seems feasible to build a 3D printing DMLS from such a CO2 engraver.