I Built a 4 Axis 3D Printer Unlike Anything You've Seen [video]
youtube.comCan someone ELI5 how is this better than a normal 3D printer? I understand how a 5 axis CNC milling machine is better than a 3 axis, but I don't see the advantages of a 4 axis 3D printer.
Typical printers will put layers bottom to top. That means for sideways overhangs, you need support. This one can put layers in any direction. That means you can print sideways without needing support.
That said, one could also use an IDEX printer to print the target material and a water-soluble support material at the same time. That way, overhangs are no problem again because you have support material under them.
Another option is to print solid, with 100% infill, then place the part in a tin filled with very fine salt, and bake it to re-melt the plastic to make a solid block w/o layer lines (note that this requires the use of a plastic which will melt and resolidify a second time and be usable).
That said, additional axes beyond XYZ seem to be the next major development for hobby CNC --- looking forward to seeing what folks come up with.
Five simultaneous axis is unlikely for hobby anytime soon since it is export controlled ;)
Beyond that its seriously annoying to home and align a five axis machine. These machines would at least need absolute encoders to really be usable for hobbyists. Some do now but it's still pretty rare.
Well there is:
https://www.pentamachine.com/pocket-nc
(but yes, most software for that is ITAR-regulated)
but for 3D printing the forces are a lot less and there's a lot of potential, and there are other cutting options such as wire EDM (saw a hobby-level implementation for that recently)
> Five simultaneous axis is unlikely for hobby anytime soon since it is export controlled ;)
Actually, you can order a cheap Genmitsu CNC, the RATTMMOTOR 5-axis upgrade, and the BIGTREETECH SKR 3 EZ controller board from China. GrblHAL is a suitable open-source firmware. And Fusion 360 will happily create the toolpaths.
So I don't understand which part is export controlled.
Well-made CNC machines are a controlled export item in the U.S. if they have the ability to precisely machine certain materials to create certain parts. See recent news stories about Haas CNCs churning out Russian weapons.
Multiple axis CAM software is also export controlled.
The folks who make the hobbyist machine I linked have a page on this:
https://www.pentamachine.com/blog/whats-the-deal-with-5-axis...
I find that quite fascinating. So it's illegal to export a high-quality CNC machine from the US. But, apparently, it's legal for China to sell a clone of that machine to those exact same people who wouldn't be allowed to buy an original from the US.
There is another important point, which is that FDM 3D prints are typically much weaker between layers than within a layer (anistropic due to the bonding). Having more control over the plane of the layers could open up some interesting design choices for functional parts.
While interesting, this seems to have all the downsides of 5 axis without any benefit over just using 5 axis (ie it's not cheaper or easier in practice)