Configuration: 9 Slots, 12 Poles
This is the typical winding used in CD-ROM motors, usually terminated Wye (Star). It's the easiest winding to do since all teeth are wound the same direction: ABCABCABC.
Pattern: A-B-C-A-B-C-A-B-C (all CW)
Common Winding Schemes
Below are the most commonly used winding schemes for BLDC motors. Each scheme shows how to wind the stator teeth and connect the three phases (A, B, C). Click on any scheme to see details.
CD-ROM [9N12P] - Wye
dLRK [12N14P] - Delta
Configuration: 12 Slots, 14 Poles
The most common winding scheme for model outrunner motors. This is a derivative of the LRK winding scheme.
Connection: Start A - End C, Start B - End A, Start C - End B
Pattern: AaAa-BbBb-CcCc (alternating CW/CCW)
dLRK Evolution [12N14P]
Configuration: 12 Slots, 14 Poles
A mutation of dLRK aimed at easier termination. The starts and ends of phases exit from the same slots, making termination foolproof.
Pattern: AaAa-BbBb-CcCc (rearranged for easy termination)
LRK [12N14P] - Delta
Configuration: 12 Slots, 14 Poles
The 'grandfather' of outrunner brushless motors. LRK stands for Lucas, Retzbach and Küfuss who documented this scheme in 2001.
Connection: Start A - End C, Start B - End A, Start C - End B
Understanding Winding Notation
Notation Legend
- A, B, C - Clockwise (CW) winding for each phase
- a, b, c - Counter-clockwise (CCW) winding for each phase
- - - Empty tooth (not wound)
- N - Number of slots (teeth)
- P - Number of poles (magnets)
Example: AaBbCc (6 teeth)
- Phase A: Wind tooth 1 CW, continue to tooth 2 and wind it CCW
- Phase B: Wind tooth 3 CW, continue to tooth 4 and wind it CCW
- Phase C: Wind tooth 5 CW, continue to tooth 6 and wind it CCW
Termination Types
Wye (Star): All phase ends connect to a common neutral point. Provides higher torque at lower speeds.
Delta: Each phase end connects to another phase start (A-end to B-start, etc.). Provides higher RPM for the same voltage.
The ratio between Delta and Wye is theoretically 1.732 (√3), but in practice closer to 1.8.