When building a CNC router or upgrading a 3D printer, the first question is usually: "Is NEMA 17 enough, or do I need NEMA 23?" Most beginners look at the Holding Torque and stop there. This is a mistake. A NEMA 23 motor isn't just "stronger"—it is physically different in ways that affect your speed, your driver choice, and your machine's ability to avoid missed steps. If you choose a NEMA 17 for a heavy gantry, it is far more likely to overheat or lose steps under cutting load. If you choose NEMA 23 for a fast 3D printer, it might actually run slower than the smaller motor. This guide explains the engineering limits of each frame size. Table of Contents 1. Physical Difference (The Frame Size) 2. Torque & Speed (The Inductance Trap) 3. Driver Compatibility 4. Selection Summary Advertisement 1. Physical Difference (The Frame Size) "NEMA" is just a standard for ...
Figure 1: The Quest for Free Energy. Perpetual motion machines inevitably fail because energy lost to friction (Entropy) cannot be recovered in a closed system. The Quest for Free Energy Perpetual motion describes "motion that continues indefinitely without any external source of energy." For centuries, engineers, inventors, and charlatans have tried to build machines that produce more energy than they consume. While the idea is romantic—a machine that runs forever and powers our homes for free—there is a rigorous scientific consensus that perpetual motion in an isolated system is physically impossible. Search for Best Books on Thermodynamics Advertisement The Physics: Why They Always Stop To understand why these machines fail, we don't need complex calculus. We just need to understand two fundamental laws of the universe. 1. First Law (You Can't Win) Energy cannot be created or d...