A BLDC outrunner motor (also called an external-rotor brushless motor) is a motor design where the rotor with permanent magnets rotates around the outside of the stator core. Unlike inrunner motors where the rotor spins internally, the outrunner's external rotor configuration enables higher torque density, smoother low-speed operation, and a superior power-to-weight ratio — making it the dominant choice for FPV drones, UAVs, and eVTOL propulsion systems .

Reenives manufactures high-quality BLDC outrunner stator cores using non-grain oriented electrical steel (0.20mm/0.35mm) with advanced epoxy powder coating — achieving ≤8.9 W/kg core loss and stacking factor ≥98.2%, critical for maximizing outrunner motor efficiency .

Reenives offers BLDC outrunner stator cores in multiple configurations to meet diverse application requirements :

• By Slot/Pole Config: 9N12P (high RPM racing), 12N14P (balanced torque/speed for UAVs & FPV), 18N20P (high torque density), 24N28P (heavy-lift / eVTOL) .
• By Material Thickness: 0.15mm (ultra-high RPM racing >50,000 RPM), 0.20mm (standard high-frequency FPV/UAV), 0.27mm, and 0.35mm (industrial outrunner applications) .
• By Stacking Method: Interlocking self-bonding, laser welding, or epoxy bonding for maximum structural integrity .
• By Insulation Coating: C5 epoxy powder coating (Class H, 180°C) with ≥1800V dielectric strength, or PI coating (220°C) for extreme thermal environments .

💡 Reenives specialty: private mould development for any custom outrunner stator geometry — including skew designs that reduce cogging torque by 30-50% for smoother drone operation .

All parameters validated by Reenives R&D center (ISO 9001:2025 certified) and third-party testing per IEC 60404-2, ASTM A937. Critical for outrunner motor designers optimizing propulsion efficiency .

📐 Data source: Reenives quality assurance lab, 2025–2026. Peer-reviewed validation shows 91% efficiency for BLDC outrunner motors in fixed-wing UAV applications . Full batch traceability and test certificates available.

Reenives BLDC outrunner stator cores power critical applications across multiple sectors :

• FPV Racing & Cinematic Drones: 2207, 2306, 2507 outrunner stators with 91% peak efficiency and instant throttle response at 45,000+ RPM.
• Commercial UAVs & eVTOL: 12N14P / 18N20P outrunner stators for 15-30kg payload with extended flight endurance .
• Fixed-Wing UAVs: Lightweight outrunner motors achieving 376W peak power, 1500g thrust, and 1.1 thrust-to-weight ratio .
• Agricultural Spraying Drones: High-torque outrunner stators with C5 epoxy coating offering 500h+ salt spray resistance .
• Robotics & Industrial BLDC Actuators: Smooth, precise torque for servo drives and robotic arms with low cogging .

1. Define motor outer diameter and stack height: Based on thrust and power targets (e.g., 28mm OD for 5-inch FPV outrunner; 40mm OD for heavy-lift UAV) .
2. Choose lamination material thickness: 0.15mm for ultra-racing >50,000 RPM; 0.20mm for standard FPV/UAV (40-80kHz PWM); 0.35mm for robust industrial outrunner motors .
3. Select slot/pole combination: 9N12P for high RPM racing, 12N14P for balanced torque/speed (most common for UAVs & FPV), 18N20P for high torque density heavy-lift .
4. Specify insulation and cooling: C5 epoxy coating for outdoor UAVs; polyimide coating for extreme temperatures; oil-compatible for EV/hybrid applications .
5. Request samples and validation: Reenives delivers first-article inspection reports (FAI) and material certificates. Prototype outrunner stator samples ready in 7-10 days after design approval .

💡 Engineering support: Free DFM within 48h and electromagnetic simulation (Maxwell) to validate outrunner stator design before tooling — send your motor spec or drawing to linda_reenives@163.com .