The Holmes Hobbies TorqueMaster Expert 550 Brushed Motor features the same quality construction as the hand wound Pro series motors, but with a machine wound armature for an affordable alternative.
 
Features:

• 550 size provides extra torque and power
• Machine wound for affordability
• 5mm web 3 slot armature- Maximizes torque, efficiency, and offers smooth startup
• Gold-plated copper brush hoods to resist corrosion and provide lowest resistance
• Aluminum heatsinks shed heat
• Filter PCB reduces EMF noise
• Brush damper reduces noise and arcing
• Can – 1.4mm thick uninterrupted back iron
• High-power FB12 ceramic wet magnets maximize torque and efficiency
• Dual Japanese Ball bearings
• Adjustable timing
• Holmes XX springs for consistent drag brake
• Holmes Soft Copper brushes for high torque and longest motor life
• Broken in for immediate installation and use

Specifications:

• Armature: 21 turn three slot
• RPM: 27,250 RPM @12v @ 12 degrees timing
• Weight: 206 grams
• Diameter: 36mm OD x 60mm length (not including shaft)
• Shaft: 1/8" diameter D shaft
• Mounting Pattern: 1" (25.4mm) M3 screws
• Input Voltage: 6-9 cell nimh, 2-3s Lithium
• Rotor: 23mm OD x 29mm length