I have to agree. I've been keeping an eye on this project for about 4 years now and there's very little in the way of a physical prototype.Quote
Honestly though, I'd not expect this team or specific project to produce a working machine any time soon. I've been following them for 3 years now I think, perhaps even longer. I check in every few months at least. In that time they've updated the wiki once and finished the design of a power supply that hasn't been built or tested and is based on a patent from the late 70s.
... there are some powders with a metal core and a thin coating of plastic or glass.
The SLS process will only melt the coating, the parts will be later sintered/remelted in an oven with some shrinkage.
Other common metal fabbing methodes are SLS with wax- or plastic powder and then "lost-cast"-moulding with embedding the parts in sand and pouring molten metal into them ...
- Minimum feature size: 0.1 mm
- Typical tolerance: +/- 0.2 mm (can be improved through machining)"]
I'm pretty sure that SLS patent has expired late last year.
Also remember that the E-beam is the cost of the vacuum chamber + pump + power supply. The laser cost would be 200W laser + optics + galvo's + power supply + inert gas chamber.
I would love to use a laser, if we found a dirt cheap way to make a 200 W fiber laser?
... another aspect is the overall resolution possible with the different methodes - the smallest spot with a [email protected] (what's more than enough for wax-SLS) is 0.03mm
My last experiments with NdYAG and fiber-lasers with common optical heads gave me a best resolution of 0.02 to 0.03mm ... the smallest spot with a NdYAG-disk-laser and a better optics for the fiber-laser was between 7 and 10 microns, what was good enough, to fuse/melt a 10 micron thick platinum wire to the surface in an additive-wire-melting setup ... but yes, this lasers will be more like 20k€
Now check, which resolutions were common with e-beam-melting -- AFAIK, most of the working (proffesssional) setups states a detail resolution of 2mm!! ... they mill/lathe the parts to the final form ...
What level of detail can be obtained with DMLS?
DMLS is available in several resolutions. At its highest resolution, the layer thickness is 0.0008” – 0.0012”
and the X/Y resolution is 0.012” – 0.016”.
The minimum hole diameter is 0.035” – 0.045”.
DMLS GENERAL TOLERANCES
Based on historical results (and application dependent) general tolerances for DMLS parts are ±0.005 inch for the first inch
and ±0.002 inch per inch hereafter (±0.2 percent). The finish of DMLS parts as built are 350 Ra – µinch.
Good to know, thanks! I don't get your second point.
Really awesome discussion. Pyrotronics do you think you could build or buy an electron gun system for less than the cost of building or buying a 200w laser? I know SEMs can easily run into the 100k plus range and simply assumed that an electron gun system would register a significant cost as well