BLDC Motor Stator Rotor Stack Supplier
Rotor Stack — Precision Stator & Rotor Stacks for BLDC Drone Motors | Reenives Stator Core Supplier
⚠️ Is your rotor stack suffering from loose layers, high core loss, or poor stacking factor? Weak interlocking, inconsistent lamination thickness, burrs, or air gaps between layers can reduce motor efficiency, cause overheating, and lead to vibration and premature bearing failure — especially in high-RPM drone brushless motors where reliability is mission-critical.
✅ Reenives is a BLDC motor stator rotor stack supplier producing matched rotor and stator stacks for drone brushless motors. With imported high-speed stamping lines, controlled stacking pressure, epoxy powder coating, and dust-free workshops, we deliver rotor stacks with low core loss, tight tolerances, and consistent stacking factor. We help 1000+ enterprises worldwide improve motor performance and reliability.
📋 Table of Contents
What Is a Rotor Stack?
A rotor stack is the assembled laminated core of a motor's rotor, formed by stacking multiple stamped electrical steel laminations together and securing them by interlocking, bonding, welding, or clamping. The rotor stack provides a low-reluctance magnetic path for the rotor's permanent magnets (in BLDC motors) while limiting eddy current losses through layer separation. The same construction method applies to the stator stack.
In drone brushless motors, the rotor stack and stator stack must be designed and manufactured as a matched pair. Their stacking quality, material grade, and dimensional accuracy directly affect:
- Core loss & motor efficiency
- Stacking factor & magnetic flux density
- Rotor balance & vibration resistance
- Air gap consistency & bearing life
A well-built rotor stack minimizes air gaps, reduces losses, and maintains consistent performance across the entire RPM range. For high-RPM drone motors, even a 0.05 mm air gap variation can cause measurable vibration and power loss.
Precision rotor stack — manufactured by Reenives with imported high-speed stamping & epoxy powder coating lines.
Types of Rotor & Stator Stacks
Rotor and stator stacks are assembled using different methods depending on motor design, cost, and performance requirements. Reenives manufactures the following types:
- Interlocked Rotor Stacks — Laminations with integral dimples or dovetails that lock together under pressure. Cost-effective, no adhesive required.
- Bonded Rotor Stacks — Laminations coated with adhesive and cured under heat and pressure. Lower eddy current losses and better damping.
- Welded Rotor Stacks — Laminations welded along the outer diameter. High mechanical strength for high-vibration applications.
- Clamped Rotor Stacks — Laminations held together with end plates and bolts or rivets. Allows for easy disassembly and repair.
- Segmented Rotor Stacks — Individual rotor segments stacked and assembled into a full ring. Higher material utilization.
- Epoxy-Coated Rotor Stacks — Individual laminations coated with epoxy powder before stacking for superior insulation and corrosion resistance.
- Magnet-Pocket Rotor Stacks — Rotor stacks with surface-mount or interior magnet slots for IPM designs.
- Custom Rotor Stacks — Private mould development for unique diameters, stack lengths, and magnet configurations.
Whether you need standard interlocked rotor stacks or custom bonded assemblies, Reenives can deliver.
Key Specifications & Data
Below are typical specifications for Reenives rotor and stator stacks. Custom values are available upon request.
| Parameter | Typical Range / Value | Notes |
|---|---|---|
| Lamination Material | Silicon steel (e.g., 35WW250, 50WW470) | Low core loss grades |
| Lamination Thickness | 0.20 mm – 0.50 mm | Thinner = lower eddy current loss |
| Rotor Outer Diameter | 10 mm – 180 mm | Matched to stator bore |
| Rotor Inner Diameter | 5 mm – 100 mm | Depends on shaft design |
| Stack Length | 5 mm – 80 mm | Affects torque & power |
| Pole Number | 4, 6, 8, 14, 28, etc. | Matched to slot number |
| Assembly Method | Interlocked, bonded, welded, clamped | Depends on application |
| Air Gap | 0.2 mm – 1.0 mm | Affects efficiency & cogging |
| Insulation Coating | Epoxy powder coating | Uniform, pinhole-free |
| Core Loss (at 400Hz, 1T) | ≤ 25 W/kg | Material dependent |
| Tolerance | ±0.05 mm (critical dimensions) | High-precision stamping |
| Stacking Factor | ≥ 95% (interlocked) / ≥ 96% (bonded) | Higher = lower reluctance |
Data source: Reenives internal testing & supplier material datasheets, 2024. Actual values may vary by design.
Applications of Rotor & Stator Stacks
Reenives rotor and stator stacks are used across a wide range of drone and brushless motor applications:
- FPV Racing Drones — High RPM, lightweight rotor stacks with low inertia and low cogging torque.
- Cinematic & Photography Drones — Smooth, vibration-free stacks for stable aerial footage.
- Agricultural Spraying Drones — Corrosion-resistant epoxy-coated stacks for harsh chemical environments.
- Industrial Inspection Drones — High-torque stacks for long endurance and heavy payloads.
- eVTOL & UAV Propulsion — Custom high-power stacks for next-generation air mobility.
- Robot Actuators — Low cogging torque stacks for precise motion control.
- EPS Motors — Low NVH stacks for automotive electric power steering systems.
- General BLDC Motors — Fans, pumps, power tools, and automotive actuators.
Reenives rotor and stator stacks power FPV, agricultural, cinematic, and industrial UAVs worldwide.
How to Select the Right Rotor Stack
Choosing the correct rotor stack for your BLDC motor involves several engineering decisions. Follow these steps:
- Determine Required Torque & RPM — Higher torque needs more stack length or larger diameter. High RPM demands thinner laminations and low-loss material.
- Select Pole/Slot Combination — Common drone motors use 12S/14P or 9S/6P. This must be matched with the stator stack to ensure proper magnetic interaction.
- Choose Lamination Thickness — For high-frequency operation (e.g., 400Hz+), use 0.20 mm laminations to reduce eddy current losses.
- Select Material Grade — Lower-loss silicon steel grades (e.g., 35WW250) reduce heat but cost more. Balance performance and budget.
- Decide on Assembly Method — Interlocked stacks are economical; bonded or welded stacks offer better performance and rigidity.
- Design the Air Gap — The gap between stator bore and rotor outer diameter must be small enough for efficiency but large enough for mechanical clearance.
- Consider Insulation & Coating — Epoxy powder coating is recommended for moisture, vibration, and chemical resistance.
- Request Samples & Test — Reenives provides free samples for qualified projects. Test core loss, stacking factor, cogging torque, temperature rise, and mechanical fit.
FAQ — Rotor Stack Parameters
Q1: What is the difference between interlocked and bonded rotor stacks?
A: Interlocked rotor stacks use mechanical features (dimples or dovetails) stamped into the laminations to lock them together under pressure. They are cost-effective and require no adhesive. Bonded rotor stacks use adhesive between layers, cured under heat and pressure. Bonded stacks offer lower eddy current losses (no interlocking burrs), better damping, and reduced vibration — a key advantage for high-RPM drone motors and low-NVH applications.
Source: Reenives engineering team, based on motor design principles and production experience.
Q2: What stacking factor can you achieve with your rotor stacks?
A: Our interlocked rotor stacks typically achieve a stacking factor of ≥ 95%, while our bonded rotor stacks achieve ≥ 96%. A higher stacking factor means fewer air gaps between laminations, resulting in lower magnetic reluctance, higher flux density, and lower core loss. The stacking factor is verified during production using controlled stacking pressure and dimensional inspection.
Source: Reenives quality control standards, 2024.
Q3: What lamination thickness do you recommend for high-RPM drone motors?
A: For high-RPM drone motors (above 10,000 RPM), we recommend 0.20 mm or 0.25 mm silicon steel laminations for both rotor and stator stacks. Thinner laminations significantly reduce eddy current losses, which helps keep the motor cool and improves efficiency. For lower RPM applications, 0.35 mm or 0.50 mm can be more cost-effective.
Source: Reenives engineering team, based on motor design guidelines and material datasheets.
Q4: How does rotor stack quality affect rotor balance and vibration?
A: Rotor stack quality directly affects rotor balance. Uneven stacking pressure, misaligned interlocks, or inconsistent lamination thickness can create density variations around the rotor circumference, leading to imbalance and vibration at high RPM. Our controlled stacking process and tight thickness tolerances (±0.01 mm) ensure uniform density and minimal imbalance, which is critical for high-RPM drone motors where vibration can cause bearing wear and reduce flight stability.
Source: Reenives engineering team, based on motor design principles and quality control data.
Q5: Do you offer epoxy powder coating for rotor and stator stacks?
A: Yes. We use imported epoxy powder coating equipment to apply a uniform, pinhole-free insulation layer on individual laminations before stacking. This coating improves corrosion resistance and protects against moisture — critical for agricultural and marine drones. For bonded stacks, we can also apply adhesive bonding instead of interlocking to further reduce eddy current losses and vibration.
Source: Reenives production specification.
Q6: Can you develop custom rotor stacks for my specific drone motor?
A: Absolutely. We support private mould development. Provide us with your required rotor outer diameter, rotor inner diameter, stack length, pole number, magnet configuration, and assembly method. Our R&D team will design and produce custom rotor stacks tailored to your motor. Tooling lead time is typically 15–25 days.
Source: Reenives custom development process.
Summary — Get Your Rotor Stack Quote Today
Ready to Improve Your Drone Motor Performance with Precision Rotor & Stator Stacks?
Reenives is a reliable BLDC motor stator rotor stack supplier with 4 years of manufacturing experience, 100+ R&D patents, and 3 production bases. We serve 1000+ enterprises worldwide with high-precision rotor and stator stacks for UAV and BLDC motors.
📦 Bulk purchasing · 🔧 Private mould development · 🧪 Free samples
🌐 Official Website: www.reenives-bldcmotor.com
📧 Email: linda_reenives@163.com
Contact us now for a free sample and tailored solution for your production scenario.
Dongguan Runlu Motor Technology Co., Ltd.
Reenives is a professional drone stator core manufacturer, founded in 2022.
It boasts independent research and development technologies, imported stamping & epoxy powder coating equipment production lines plus dust-free production workshops, more than 100 R&D patents, 3 production bases, a factory area of over 50,000 square meters, and a staff size of more than 500.
From production to sales, we support bulk purchasing, private mould develop, and samples making, and can provide tailor-made perfect solutions for your production and usage scenarios. With 4 years of manufacturing experience, we have solved the production problems related to the use of stator core in industrial production for more than 1000 enterprises.
We can ship globally (with complete export qualifications). Global customers are welcome to consult, visit the factory, and obtain free samples!
Reenives Runlu Motor BLDC Motor Rotor Stack
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