Motor stacks (also called lamination stacks or stator/rotor stacks) are precision-assembled bundles of thin silicon steel laminations that form the magnetic core of a brushless DC motor. The stack consists of stamped laminations stacked to a specific height and bonded or interlocked to maintain structural integrity. In drone motors, the quality of the motor stack directly determines magnetic flux density, eddy current losses, and thermal behavior . Reenives manufactures high-quality motor stacks using non-grain oriented electrical steel with advanced epoxy powder coating — achieving stacking factor ≥98.2% and reducing eddy current losses by up to 38% compared to conventional laminations .

Reenives offers motor stacks in multiple configurations to meet diverse application requirements :

• By Stack Type: Stator stacks, rotor stacks, and matched stator-rotor sets.
• By Slot/Pole Config: 9N12P (high RPM racing), 12N14P (balanced torque/speed for UAVs), 18N20P (high torque density), 24N28P (heavy-lift / eVTOL) .
• By Material Thickness: 0.20mm (high-frequency FPV/UAV), 0.27mm, and 0.35mm (general industrial).
• By Stacking Method: Interlocking self-bonding (most common for FPV), laser welding, or epoxy bonding .
• By Insulation Coating: C5 epoxy powder coating (Class H, 180°C–200°C) with ≥1800V dielectric strength .

💡 Reenives specialty: private mould development for any custom motor stack 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 .

📐 Data source: Reenives quality assurance lab, 2025–2026. SGS verification report #SGS-RL-2421 . Full batch traceability and test certificates available.

Reenives motor stacks power critical applications across multiple sectors :

• FPV Racing & Cinematic Drones: 2207, 2306, 2507 motor stacks with instant throttle response and 92% peak efficiency at 45,000 RPM .
• Commercial UAVs & eVTOL: 12N14P / 18N20P motor stacks for 15-30kg payload with extended flight endurance.
• Agricultural Spraying Drones: High-torque motor stacks with C5 epoxy coating offering 500h+ salt spray resistance .
• Industrial BLDC Actuators: Robotic arms, servo drives, and gimbal motors requiring ultra-smooth torque (<1% cogging ripple).
• Delivery & Logistics Drones: Heavy-lift octocopters with optimized thermal dissipation .

1. Define motor outer diameter and stack height: Based on thrust and power targets (e.g., 28mm OD for 5-inch FPV drone).
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 motors .
3. Select slot/pole combination: 9N12P for high RPM racing, 12N14P for balanced torque/speed (most common for UAVs), 18N20P for high torque density heavy-lift .
4. Specify stacking method and insulation: Interlocking for high-volume production; epoxy bonding for lowest eddy loss; C5 epoxy coating for outdoor UAVs .
5. Request samples and validation: Reenives delivers first-article inspection reports (FAI) and material certificates. Prototype samples ready in 7-10 days after design approval .

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