An introduction to the play and stop hysterons.
Analysis of the YASA Record-Breaker Axial Flux Motor, and What Everybody Gets Wrong
Update August 2026 This post was originally written before more information surfaced. What I did wrong, fundamentally, was assume a rather mechanically-robust surface speed, resulting in a very high torque density requirement, leading to a saturation nightmare, leading to the…
On Eddy-Current Iron Losses
Preface I had already written this post up to the analytical methods section when WordPress saw fit to lose all my progress for some reason. So, if you get an aura of pissed-offness from the first few sections, it’s not…
Fluid Flux Barriers
Summary You may have come across the term ‘fluid flux barrier’, or ‘fluid barrier’, or in any case fluid-something, in the context of synchronous reluctance motors. I certainly have, on multiple occasions. In fact, I encountered the term multiple times…
Getting Started in Consulting – Electric Motor Design Version
Summary Getting started in consulting electric motor design. The title says it all. Just my condensed thoughts on the topic. Colossal Disclaimer I. Do. Not. Teach. Consulting. There, I said it. I mean, if you take one thing out of…
On split ratios
The split ratio, defined as the rotor OD divided by the the stator OD, is one of the key dimensions defining the performance of an inrunner electrical machine. For a (relatively) fixed OD and stack length, it’s probably the most…
Finding the operating point of a motor
Finding the operating point of an electric motor is no longer as simple as it used to be. I mean, in the past, or in the textbooks and course slides we often see during our studies, it was simple. Just…
Axial versus Radial Flux – First Principles
Which is better – axial or radial flux? The correct answer is complex and depends on a million things, but here’s a first-principles comparison.
Tesla’s ‘Carbon-Wrapped’ Motor
Tesla Model S Plaid will apparently have carbon fiber retaining sleeves in their motors. Here are some thoughts on what this might mean.
Mahle Magnet-Free Motor – First Impressions
Mahle’s new EV motor is marketed with being rare-earth free and wirelessly excited, but what is the reality? Here are some first thoughts and impressions.