MotorCell Is Not Just a Revolution in PCB Motor Design; It Is 1.6 Billion Revs!

Carl Bugeja's latest video unveiled the MotorCell, a groundbreaking PCB-based motor from microbots resulting from six years of research, experimentation, and development. This innovative open source motor concept surpasses Bugeja's previous attempts. For instance, it is robust enough to spin continuously for 30 days at over 30,000 RPMs, equivalent to at least 1.6 billion rotations!

In the past, we have seen Bugeja deliver crazy PCB-based or related projects, such as movable projects like a flex-circuit actuator and heating projects like a PCB that reflow solders itself. These learnings, experiments, and unique products have led to the creation of this latest achievement.

MotorCell is a low-power brushless motor with a 6-layer PCB as its stator. A key to making the MotorCell so compact is a ROHM BD67173NUX integrated circuit (IC). This single-chip motor controller accepts PWM input for speed control and eliminates sensors by incorporating back-EMF sensing.

The PCB is only the stator part of the MotorCell. The rotor, or moving part, is a shaftless design that contains four magnets in a bearing. It took several iterations and vendors to develop a suitable rotor that went from working briefly to 20 motors running continuously for a month! In their tests, Microbots ran the motors between 36,000 and 37,000 RPMs. So, in the long term, they appear to be suited for speeds up to 30,000 RPM.

While they have high RPMs, the motors have relatively low torque. For example, they are unable to spin a large propeller. (However, future improvements could change that limitation.) MotorCell does well with applications like spinning smaller objects such as thin 3D-printed decorations or creating haptic feedback with an off-center mass. Bugeja's original motivation was, of course, a tiny robot. However, t demonstrate just how fast the motors spin, he made a disc shooter inspired by Spider-man's (fictional) wrist-based web shooters.!

Check out the video for full details about MotorCell and the history of what it took to get to this point. Since Microbots open sourced the design, you can build your own (after ordering the necessary components) or purchase a completed MotorCell for €12.50 to 14.