Assessing the feasibility of BLDC Motor integration in a FFF extruder

Abstract

3D printing has increased in popularity as a way of quickly and efficiently creating a multitude of different objects from raw materials. Filament based machines, referred to as Fused Filament Fabrication (FFF) or Fused Deposition Modeling (FDM) machines, have become widely available to consumers and businesses alike.

One of the many considerations when comparing 3D printers has been print speed. Users understandably want print speeds to be as fast as possible without sacrificing print quality. As such manufacturers have been developing ever faster machines. One of the many difficulties in improving print speed while maintaining quality has been the weight of the extrusion head. A heavy extruder is hard to move steadily.

For a typical Direct Drive -style extruder, more than half of the weight can come from just the feed motor. While the standard setup in the industry has been to use stepper motors, a potential solution could come from Brushless Direct Current Motors (BLDC). BLDCs are typically much lighter than comparable stepper motors, and as such could help in making the extruder assembly lighter to enable faster print speeds.

The main objective of this thesis was to study the viability of replacing the feed motor in a filament-based 3D printer with a BLDC motor instead of the traditional stepper motor. This alternate approach was studied both by way of exploring relevant literature as well as designing, assembling and testing a simple prototype of a motor system. The motor was also shortly compared to a NEMA 17 stepper motor typically used in such applications.

After comparing the motors and analyzing the test results, it was noted that the subject has potential for further and more in-depth research. Despite requiring solutions to certain drawbacks of the different motor design, and as such appearing commercially non-viable, with more research a proper solution and a different perspective could be achieved.