Out-slot

OD: 31mm

ID: 14mm

Frequently Asked Questions – Drone Stator Core (BLDC Motor Stator Lamination Stack)

Q1: What is the difference between 0.15mm, 0.20mm, and 0.35mm stator lamination thickness? Which one should I choose for my drone motor?
Thinner laminations (0.15mm – 0.20mm) dramatically reduce eddy current losses at high electrical frequencies (20kHz – 40kHz), which is common in high-KV FPV and racing drone motors. They provide 5–8% higher efficiency but cost more. Thicker laminations (0.35mm) are suitable for low-RPM, high-torque industrial UAV motors where cost is a priority. For most 6S FPV motors (2400KV+), 0.20mm is the optimal balance. For heavy-lift agricultural drones running at lower PWM frequencies, 0.27mm – 0.35mm is sufficient.

Q2: What is the maximum stator outer diameter (OD) and stack height you can manufacture for a heavy-lift drone?
Current manufacturing capabilities support stator OD up to 250mm and stack height up to 110mm using modular progressive tooling. For heavy-lift coaxial drones (e.g., 25kg+ payload), typical delivered sizes include OD 62mm with 28mm stack (6215 stator) and custom 120mm tall stacks for eVTOL prototypes. Minimum order quantity for fully custom dimensions starts at 200 pieces.

Q3: How does epoxy powder coating improve stator performance compared to standard varnish?
Epoxy powder coating provides a uniform dielectric barrier (2.5kV breakdown voltage) and creates a smooth, rounded slot surface. This reduces friction on magnet wire during automated winding and eliminates sharp edges that cause insulation scratches. Production data shows epoxy-coated stators experience 40% fewer turn-to-turn short circuit failures during mass winding. Additionally, epoxy coating passes 120+ hours salt spray test (ASTM B117) , making it essential for agricultural and maritime drones.

Q4: What material certifications and traceability do you provide for aerospace or military drone projects?
Every stator batch can be supplied with EN 10204 Type 3.1 material certificates including full mill trace codes, chemical composition, and magnetic property verification (core loss, permeability). Optional third-party SGS or TÜV inspection is available. All production batches are retained with 10-year traceability via laser-engraved lot numbers.

Q5: Can you manufacture stator cores with integrated slots for temperature sensors (NTC) or unique mounting patterns?
Yes. Through custom progressive tooling (private mould development), stator laminations can be stamped with integrated notches for NTC thermistors, asymmetric keying features for orientation, or precision mounting bosses. Over 30% of industrial drone customers currently use such custom mechanical integrations. Tooling lead time is 25–35 days; sample MOQ is negotiable.

Q6: What is the typical core loss (P1.0/400) for a 0.20mm drone stator lamination?
For premium 0.20mm non-grain-oriented electrical steel (grade 35ZH130), the typical core loss at 1.0 Tesla / 400Hz is ≤ 8.2 W/kg when measured according to IEC 60404-2. Budget-grade 0.20mm material may exceed 10 W/kg. All certified shipments include a core loss test report from an Epstein frame measurement.

Q7: What stacking factor can I expect for interlocked vs. bonded stator stacks?
Precision interlocked stacks achieve a stacking factor of ≥ 97.2% (measured per ISO 27547). For welded or epoxy-bonded stacks without interlocking, the factor is slightly lower at 96.5% – 97.0%. Lower stacking factor reduces effective magnetic flux density and increases required copper fill, so interlocking is strongly recommended for high-power-density drone motors.

Q8: Do you support private mould development for non-standard slot/pole combinations (e.g., 18N24P, 24N28P)?
Yes. Reenives supports any custom slot/pole combination and stack geometry through private mould development. Over 150 custom tooling projects have been delivered since 2022. Typical lead time for new moulds is 25–40 days depending on complexity. Sample stator stacks can be produced within 5–8 days after tooling completion.

Q9: What is the minimum order quantity (MOQ) for custom stator laminations?
For standard existing tooling (common sizes like 2207, 2306, 2814, 6215), MOQ is as low as 500 pieces. For fully custom private mould development, MOQ typically starts at 2,000 – 5,000 pieces per year, negotiable based on project scale and exclusivity agreement. Sample quantities (50–200 pieces) are always supported for validation.

Q10: How do I verify stator core quality before mass production? What sample process do you offer?
Reenives offers a standard 3-step sample validation process:
① Material certificate & simulation – BH curve data and core loss estimation provided within 2 days.
② T1 sample (soft tooling) – 20–50 pcs delivered in 5–8 days for fitment and basic magnetic testing.
③ T2 sample (hard tooling) – 200–500 pcs delivered in 20–30 days for full validation including thermal cycling, salt spray, and efficiency dyno testing.
Full dimensional report and core loss test report included with every sample batch.