[EricH]

Originally Posted by DampRobot

We've made a few sensor mounts and stuff like that, but they're fairly inaccurate and shatter into layers very easily. As far as I know, there's no 3D printer within an average teams budget that doesn't use this process, so my comments were mainly in regard to printers of that type.

Funny, I've not seen those issues. Maybe you had a bad printer, or a lousy parameter set (the only problems I've seen tended to stem from lousy parameters in the build). Or, as you note, it's an early model and some bugs may not have been worked out.

I've also gotten some stuff printed online through an SLS process, and it was quite weak too. Instead of layers being fused together, it was grains.[...] I've never handled metal SLS parts, but I'd imagine that they'd suffer from weakness in the same way that SLS plastics would, because they're still composed of fused grains.

Yes, they are composed of fused grains. Name a single metal that ISN'T*. Just some are more fused than grains. I'm not an expert in SLS, but there is one who hangs out on Chief Delphi. Suffice it to say that the strength--from what I've seen--is pretty reasonable compared to a solid piece, though certainly not 100%.

I have heard hype about 3D printed titanium or aluminum through SLS, but for the moment I'm inclined to believe that this is has yet to break though to traditional manufacturing or even mainstream prototyping. We're certainly not 3D printing replacement car parts yet.

Actually, you're right. Most of the manufacturing I've seen, in large scale at least, is DLD, which is a VERY similar process. This includes parts for a Formula SAE car. P.S. 3D printing is not traditional manufacturing, by any stretch of the imagination.

I'm very interested to hear that aerospace companies are making parts through SLS, but I suppose that with the kind of performance they'd require, they could afford to be an early adopter.

Or the amount of time they don't have, or the costs they need to drive down. I've heard that a part that could take months to get done via conventional methods (machining and molding) lost to an SLS part that could be done in a week, mainly because it was needed the previous week.

Maybe by the time I'm out of college, well be seeing cheap metal 3D printers in the wild. At that point, I'd become very interested.

I doubt that, at least on the metal side. Most of those use a laser. Guess what happens to need a lot of shielding, which costs money? Just something else for someone to work on.


tl;dr: While the layer structure or grain structure may appear weak, it can actually be quite strong if built properly. Proper building may take some time to achieve; once achieved, it should stay that way for a while.


*All metals have a grain structure. Whether you notice it or not is another question. If you go into mechanical engineering as a career, you'll hopefully get a lab on materials which includes looking at grain structures in a microscope. It's quite interesting. Sometimes you can see it in a fractured section of metal.