We’ve noticed a trend lately that advanced 3D printing people are calling their normal print setup as 2.5D, not 3D. The idea is that while the machine has 3 axes, the actual geometry generation is typically only in the X and Y axis. The Z axis simply lifts up to the next layer unless you are working in vase mode. [Teaching Tech] wanted to experiment with real 3D printing where the Z axis actually helps build the shape of the printed object, not just advancing with each step.

As it turns out his first investigation linked back to one of our early posts on the topic. There’s been more recent work though, and he found that too. It took a little surgery to get more Z clearance, but nothing too serious — just a movement of a fan.

The problem is, of course, if you start having the head moving up and down, it needs to have a very low profile so you aren’t bumping into things. This is usually not as big a problem with conventional printing because the head is always a little bit over the printed object.

A special slicer computes the way to move the head around in all three directions. The only thing we’d worry about is that most printers don’t expect much movement in the Z axis. For example, many printers use belts on the X and Y axis but use leadscrews for Z. You might have issues with backlash being worse, for example, or need to lubricate the Z axis more than usual.

One nice thing about not using layers is that layer lines do not appear in the same way they do with conventional printing. You can really see the differences in some of the example prints in the video. It may be that one day having a 3D print sliced into layers will be as quaint as putting data on a floppy diskette seems today. There’s a long way to go, but there’s a lot of work to push in that direction.