Firma 3900Kv 4-Pole Brushless Motor

The Spektrum Firma 3900?Kv 4?Pole Brushless Motor is a high?RPM sensorless upgrade for 1/10?scale 4WD vehicles like the ARRMA GROM BLX. Featuring a low?cog 4?pole rotor, CNC?machined aluminium housing, pre?installed bullet connectors and a durable 5?mm steel shaft, it delivers smooth, efficient performance at 3S voltage levels.

Features

• Sensorless brushless inrunner with high?tolerance 4?pole rotor design
• CNC?machined aluminium can, insulated high?purity copper windings
• 5?mm hardened alloy steel shaft (supports SafeD?5 pinion)
• Pre?installed 4?mm gold?plated bullet connectors
• Ideal for 1/10 scale models running up to 3S LiPo

What’s in the box

• Spektrum Firma 3900?Kv brushless motor with connectors
• Instruction manual

Needed to complete

• Spektrum Firma Smart ESC (e.g. 130) or compatible standard ESC rated ??45?A
• 2S–3S LiPo battery (7.4–12.6?V)
• Full?range transmitter and receiver for your radio system

Specifications

• KV rating: 3?900?Kv
• Application: 1/10?scale surface vehicles
• Input voltage: 2?3S LiPo (up to 12.6?V)
• Maximum continuous current: 45?A
• Approximate output power: 1?420?W @ 3S
• Efficiency: 80?%
• Outer diameter: 36?mm (1.4?in)
• Length: 60?mm (2.35?in)
• Shaft diameter: 5?mm (0.2?in)
• Weight: approx.?253?g (8.9?oz)
• Connector type: 4?mm gold?plated bullet
• Technology: Sensorless 4?pole brushless motor