Non-planar 3D printing: Everything you need to know.


Non-planar 3D printing allows you to eliminate the natural coating of stairs that regular printing methods produce.

Non-planar 3D printing: Everything you need to know.

Have you ever noticed those ugly level-by-level lines in 3D concave printed pieces? The issue is known as the ladder effect, and is prevalent in regular printing in FDM 3D. It is because normal 3D printing methods, unlike the name, are actually more like “2.5D”: Only the X and Y axes move simultaneously; the Z axis is only in motion when the X and Y axes stop to let the print head go up to print the next layer.

Non-planar 3D printing is a different FDM printing style, which allows “true” 3D printing on the curvatures of parts. This unique print style was born from experiments carried out in 2018 by researchers at the University of Hamburg in Germany.

Non-planar printing is the process of printing parts with curved layers in which curvature extends across the X, Y, and Z axes. This print style allows you to print curved parts with a smoother external finish, regardless of other factors such as filament type, post-processing, and so on.

Suitable Model Types

Although printing in a non-planar way is difficult due to the limitations of technology, it can be useful to print parts with great concave characteristics. This is especially fruitful for curved parts such as wings because non-flat printing can improve the aerodynamics of the part, according to researchers at the University of Hamburg. For example, this model of airplane wings (pictured above) has no stair box.

Compatible software

The technology, specifically the software, used for non-gliding 3D printing, is still very underdeveloped. The main system required for this print style is a special program currently only available as an altered version of Slic3r. It is the only popular slicing software capable of developing a G code for 3D printing not gliding, but if the method gainpopularity, you can expect other programs to follow it. In this article, we will review how 3D printing works, its benefits and disadvantages, as well as a basic guide on how to achieve it.

Non-planar 3D printing: Everything you need to know.

As you can probably guess, non-planar printing is significantly more complex in the way it works than normal FDM printing. It also requires some modifications to your FDM 3D printer to work with regard to the nozzle and print head. For this printing method to work, the nozzle needs more space in the print head than some printers offer, especially if the print head has a large heatsink, fans, and blowers. This clearance allows the nozzle to move safely along the X, Y, and Z axes simultaneously. As the nozzle extends further down by itself, the print head can move from side to side and up and down without disturbing printing.

When printing something using non-planar printing, the 3D printer first prints the base of the part in a normal way (2.5D). This is because, to print bends, the printer must first establish a base with a small curve and then build on top. The base with the small curve will probably display the finish of the stairs, but later, in printing, this will be covered.

Once the curved base is finished, the printer then switches to a “real” three-dimensional printing style, adding layers to the small curvature of the base while moving along the X, Y, and Z axes at the same time. One can think of this movement as adding blankets to a semi-spherical ball, with each blanket representing a layer and the ball representing the base of the impression.

By doing this, the printer avoids the production of stair coating lines in your print. The non-flat curve will still have rows of layers across the Z axis, but these will be curved instead of straight.

Non-planar 3D printing: Everything you need to know.

Non-planar printing has, like all things, some advantages and disadvantages. Let’s take a closer look.


  • Produces a mixture of curved lines and regular layers that produce a smooth finish on threedimensionally curved objects
  • Vertically stronger parts
  • Improves aerodynamics for parts


  • Requires a specific print head design with a extended nozzle
  • Technology is underdeveloped
  • You can still see layered lines (only eliminates the effect of stairs)
  • Requires Linux software to run the changed version of Slic3r (the main way to make non-planar printing)
  • Not useful or efficient for uncurved prints
Non-planar 3D printing: Everything you need to know.

Installing non-planar 3D printing can be quite difficult. For this guide, let’s just review the main steps and basics.

As we mentioned earlier, to make your machine compatible with 3D printing not gliding, you’ll need to have a little free space around your beak. It should extend at least a few millimeters beyond the rest of the print head (try by about 7 or 8 mm). This can be done by using a longer throat or by removing most of the additional features of your print head, such as the heatsink, fans and fan cover.

After you have made the necessary adjustments, you will need to download the software and adjust the settings. Here are the main steps:

  • Download the files for the custom non-planar version of Slic3r on Linux. If you don’t have a Linux device, you can check the GitHub page solutions page.
  • Open the Slic3r version and edit the print bed sizes, offsets, nozzle angle, and other machine configurations as needed.
  • Measure the offset of your nozzle (distance from the rest of the print head to the nozzle) and connect this value to the Slic3r.
  • Open the curved file that you want to print in a non-planar way.
  • Slice and print!

While it may not sound like a complicated process, it’s not as simple as it sounds. You may encounter program problems and error messages, and you’ll need to use the GitHub troubleshooting page of the Slic3r version to fix them.

While this process is a bit tricky for now, in case the printing does not plan to gain popularity, we can expect more slicers to offer modes or non-flat versions.