Lecture Notes: Newbie Drone Motors - Smooth V2 and Flow V2

Overview

• Focus on two motors from Newbie Drone: Smooth V2 2306.5 and Flow V2 2306.5.
• Bench tests and thrust stand performance comparisons against other 5-inch motors.
• Key feature: Unique single piece magnet design of the Smooth V2.

Flow V2 Motor

Design and Features

• Unibell Motor: Aluminum bell extends over the flux ring with a 10-spoke design.
  • Concern: Sharp edge could be prone to denting in crashes.
• Disassembly: Motor bell attached to stator by M3 screw (requires force and possible heating to remove).
• Magnet Placement: Magnets glued securely into the bell with adhesive.
• Top Bearing Protection: Lacks typical rubber o-ring and washer, potentially making it more vulnerable to impacts.
• Dynamic Balancing: Evidence of balancing within the motor.

Stator Design

• Traditional design with two 9x4 mm bearings.
• Neat single strand windings preferred for high power and performance.

Smooth V2 Motor

Design and Differences from Flow V2

• Similar bell design (10-spoke, unibell construction).
• Screw Type: M2 countersunk screw instead of M3 (M2 may strip more easily).
• Unique Feature: Single piece ring magnet around the motor edge.
• Top Bearing Protection: Similar to Flow V2, lacks o-ring and washer.

Magnet Production Process

• Standard Neodymium Magnets: Produced by melting elements (neodymium, iron, boron) in vacuum, rapidly cooled, treated with hydrogen, and sintered.
• Bonded Magnet for Smooth V2: Involves mixing neodymium powder with polymer binder, molded into shape, then cured at low temperatures.
  • Allows for equal magnetization in all directions but results in lower maximum field strength compared to sintered magnets.
  • Typically contains 95-97% neodymium material.

Magnetic Strength Comparison

• Smooth V2 (Bonded Magnet): Peak field strength around 400-430 mT.
• Flow V2 (Sintered Magnet): Peak field strength around 470 mT (approx. 10% stronger).

Performance Testing

KV Measurement

• Smooth V2 tested lower than stated KV (1650 KV vs. 1750 KV).
• Flow V2 also tested lower but closer to spec (1800 KV vs. 1850 KV).
• Switching bells affects KV due to changes in magnetic strength.

Thrust vs. Electrical Power

• Smooth V2 produces less thrust at full throttle compared to Flow V2 (lower KV).
• Swapping the Flow V2 stator with Smooth V2 bell results in more maximum thrust despite lower efficiency.

Torque vs. RPM

• Torque measurement shows the Flow V2 generates greater torque (0.225 Nm) compared to the Smooth V2 (0.2 Nm).
• Indicates lower performance of Smooth V2 in terms of responsiveness and torque.

Conclusions

• Smooth V2 motors may not be optimized magnetically compared to other brands.
• Marketing of smooth motors potentially misleading; smoothness relates to balancing rather than magnet strength.
• Stronger magnets and higher torque lead to better responsiveness for flight controllers.

Support and Contributions

• Encouragement to support the channel through Patreon.
  • Membership offers access to special Discord areas and input on future FPV designs.

Final Thoughts

• Emphasis on the need for motors that are responsive and torque-rich for better flight experience.