Software - multipoledynamics.com

Benefits - What will MaxiSlicer make possible?

Non-planar 5-axis FDM 3D printing will introduce three main advancements over regular 3-axis FDM printing:

Improved strength

Improved surface quality

Reduced material usage

1. Strength:

There is one major challenge with FDM printing parts with high requirements for strength: non-isotropic mechanical properties. The root cause of this lies in the 3D printing technique itself. Both the material extrusion and fusing with underlying sections relies on heating the filament in a single combined process stage. Careful control over extrusion parameters limits the freedom to control material fusing, and vice versa. In practice, this tends to lead to sub-optimal fusing between extrusion lines, which manifests itself as reduced mechanical strength perpendicular to the print layers.

Interestingly, the underlying issue is also present within each individual layer. There, it simply lacks the relevance of inter-layer mechanical strength. This is due to the fact that print lines are typically of a more complex shape than straight lines - the one-dimensional analogue shape to 2D planar print layers. This extra complexity is sufficient to lead to the widely accepted outcome - FDM prints are at their weakest between print layers. Or more to the point, it prevents the weakness from showing up within individual layers. This limitation is inherent to all 3-axis FDM prints. However, it is not a fundamental limitation. We can do better.

5-axis FDM printing can be used to apply the above strengthening principle to all directions of the part through non-planar print layers. If individual extrusion lines - the underlying source of both the strength and the weakness of printed objects - can be freely oriented in all three dimensions the limitation and issue of non-isotropic mechanical properties of a finished part can be lifted. No more weak directions!

At its most simple, this approach utilizes the same principles that are already being used in 3-axis printing to remove weak directions in finished parts.

2. Surface Quality

5-axis FDM printing improves surface quality in two ways: New level of control over print layer geometry and elimination of support material.
All versions of FDM 3D printing approximate the shape of an object layer by layer. Within each layer most shapes can be reproduced to a satisfactory degree with the right print parameters and nozzle size. Even natural shapes and curves can be reproduced well enough that they appear identical to the original shape. However, this level of resemblance is broken by the layered structure of finished parts. Approximating the original shape in a direction perpendicular to print layers unavoidably must be done in a stepwise manner - this is simply the nature of FDM printing. All that can be done is to fine tune the layer thickness and orientation to mitigate this - and this is exactly what 5-axis FDM printing does well.

Regular 3-axis FDM systems only allow the thickness of print layers to be varied throughout a single object. The layer orientation must be fixed during print preparation, and it cannot be changed afterwards. Should there be features on an object that are reproduced best at different layer orientations, a compromise must be made. Generally the approach is to minimize overhangs. The steeper an overhang, the more prominent the step pattern on the part surface. Reducing print layer thickness makes the step pattern finer and, therefore, improves the surface quality but it comes at the cost of increased print time.

WIth 5-axis FDM printing the layer orientation can be changed mid-print to suit the needs of individual features on a single object. This results in better reproduction of the original geometry without increased print time. This is great - for both aesthetics and part tolerances!

There is an additional limitation to the surface quality on 3-axis systems - support material. Each print layer can only be extended a limited distance outside the previous layer supporting it without sagging. The usual solutions are to decrease layer thickness, leading to increased print time, and adding extra support material that doesn't belong to the original part design. While the latter is a powerful technique, it comes at a cost. The support material has a tendency to partially fuse with the object it supports. This can lead to noticeably rough surface finish, significantly worse tolerances, and a need for additional post processing. This issue can be mitigated but not fully avoided by carefully tuning print settings with each job. Finding universally applicable settings can be difficult due to the wide range of print jobs a typical printer will execute.

Overall, using support material is a valuable tool but one that is best avoided whenever possible. The additional freedom in 5-axis printing to rotate objects mid-print is a highly effective way to eliminate the need for support material and the costs that come with it. Even fully horizontal overhangs can be printed without any supports.

3. Reduced Material Usage

This is very simple - use less material, save time and money.

There are two ways 5-axis printing can significantly reduce material usage: eliminated support material and printing fully hollow objects. The former is self-explanatory, but the latter perhaps not so much. Regular 3-axis prints typically include an internal support structure in printed objects - infill. It increases the strength of the final part, but it also allows closing off objects with flat tops and printing surfaces leaning inwards. That's all positive, of course, but for objects like these infill cannot be easily avoided. Should you only wish to print a quick prototype that doesn't need the extra strength, infill only adds to time and material costs.

5-axis FDM priting allows both support and infill material usage to be minimized, or even fully eliminated. Steep overhangs and even fully horizontal surfaces can be printed without any extra material for support.

Why hasn't this been done before?

5-axis Filament Deposition Modeling (FDM) 3D printing has suffered from a chicken vs. egg problem with the availability of printers and a slicer. 5-axis machines are not available on the market today because there is no viable software to run them and the software hasn't been developed because there are no machines to use it.

Machinists have been running with more than 3 axes for a very long time already. For them 5-axis machining is a well-proven and widely used extension to the capabilities of 3-axis machining. CAM software tools available on the market today can be used to create highly intricate and complex designs with very high tolerances. Both the software and machines are capable of working with materials that are far more demanding than plastic filaments. Overall, everything that is needed for 5-axis FDM printing has already come to be considered business as usual in machine shops. So why not 3D printers? Nobody has been willing to break the chicken vs. egg situation and develop an easy-to-use slicer.

Building capable 5-axis motion systems is, in comparison, not all that difficult. We believe that developing an easy-to-use 5-axis slicer that can be expanded with new motion system designs will finally break the chicken vs. egg situation and make 5-axis FDM printing a consumer-level technique. We hope to see our software support both our own motion systems and ones developed by many others in the future. Initially, at least until the slicer reaches its first stable release, we plan to work with a limited number of designs. In the long run we hope to expand the software to fully user-defined motion systems, similar to how current slicers support user-defined print bed dimensions.