Motor winding design, done right.
Six professional-grade engineering calculators: winding design, wire sizing, slot analysis, Newton-Raphson equivalent circuit extraction, T-circuit performance analysis, and rotor eccentricity testing. With 1,285 reference motors and full calculation history.
Integral-slot, three-phase. The full calculator adds flux, current, wire size and winding weight.
Run it on your motorWhich of these is you?
The tool is the same. Where you should start is not.
You rewind for a living
Look a machine up before you start. 1,285 motors with the slot count, coil pitch, turns and wire already recorded, so you are checking your work, not starting from a blank page.
Start with the catalogueYou have one motor on the bench
Measure the bore, count the slots, read the plate. You get the winding factors, the slot-by-slot distribution and a balance check for that machine.
Work through one motorYou are learning this
Every result shows the working: why a shortened span chords the winding, what thin back iron does to the current it draws. The numbers arrive with their reasons.
See a worked exampleEverything a rewind needs
Each calculator is a full sheet: inputs, results, and the winding drawn out slot by slot.
Compute synchronous speed, winding factors (Kd, Kp, Kw), flux density, turns per coil, and wire CMA.
Add slot geometry (width, depth, insulation) for slot fill factor analysis and packing efficiency.
Select optimal AWG or metric wire based on current and desired current density with a ranked comparison table.
Extract R1, X1, R2, X2, Xm, and Rm from nameplate and no-load data using Newton-Raphson iteration. Generates torque-speed curves and performance at multiple load points.
Analyse the T-equivalent circuit at 50%, 75%, and 100% load. Two methods: Vectorial and IEEE 112-B. Full torque-speed curve and phasor diagram included.
Detect shorted turns and air-gap non-uniformity per IEEE 115. Enter per-pole voltages and get an instant GOOD / QUESTIONABLE / BAD diagnostic with per-pole deviation breakdown.
Browse 1,200+ reference motors by HP, poles, and voltage. Import directly into the winding calculator.
Every calculation saved, named, and reloadable.
See it in action
The workspace, as it is today. Light and dark, on any screen.
Worked all the way through, on a real motor
Not a claim about accuracy. An actual machine from the catalogue, calculated here on this page by the same engine the product uses. If the maths ever changed, these figures would change with it.
Coil throw 1–10 · 21 turns · AWG 16 · stack 13 in · bore 16 inRun one on your own motor
- 0.9598
- Winding factor
- 1.0000
- Chord factor
- 0.9598
- Distribution
- 20.2
- Equivalent turns
- 9
- full pitch (slots)
- 3
- slots / pole / phase
Three-phase, star-connected. The coil spans the full pole pitch (nine slots for a 36-slot four-pole machine), so the chord factor is exactly 1 and the winding factor is set by distribution alone. The catalogue already held this motor; a rewinder would not have typed any of it.
Save every calculation
All your calculations are saved to your account. Name them, browse your history, and reload any result at any time.
Ten free calculations. Then $120 a year.
No card to start. Every calculator and the full catalogue are open from the first minute.