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: Modern flywheels act as mechanical batteries, storing kinetic energy (0.5 Jω²) for rapid release. The energy-storage capacity of a flywheel is determined essentially by two factors: its Polar Moment of Inertia (J) and its Rotational Speed (ω) . While modern "Grid-Scale" flywheels are used as massive batteries, the principal use in machine design is to smooth out ripples in shaft speed. By absorbing torque spikes (excess energy) and releasing it during dead spots, a flywheel acts as a mechanical reservoir. 📘 Shop Standard Machine Design Handbooks Advertisement Step 1: Determining the Allowable Fluctuation (C s ) No machine runs at a perfectly constant speed. The goal is to keep the variation within harmless limits. We define this limit as the Coefficient of Speed Fluctuation (C s ) : C s = ( ω max - ω min ) / ω avg Where ω (omega) is the angular velocity in rad/s . ...