BrotherHobby R3.5 2205

What it pulls

BrotherHobby’s own bench test, one line per prop. Drag across the chart to move the throttle; the model above follows.

What you get for $18.00

• 881 g on 6S

  On BrotherHobby’s 6S bench the motor pulled 881 g at full throttle on a 3.5-inch five-blade, drawing 31.5 A.

  Source: BrotherHobby test sheet

• Made for a 3.5-inch five-blade

  BrotherHobby pairs it with a 3.5-inch five-blade prop in a ducted cinewhoop and says the thrust leaves room for a range of cameras.

  Source: BrotherHobby parameters, BrotherHobby infographic

• TU1 wire, N52H magnets

  TU1 enamelled wire with a high slot fill, N52H arc magnets at a consistent air gap, and 0.2 mm silicon-steel laminations.

  Source: BrotherHobby materials

• Hard-anodised 7075

  Bell cap and base in hard-anodised 7075 aluminium, hollowed out to save weight and help cooling.

  Source: BrotherHobby materials

What to pair it with

Our reading of BrotherHobby’s numbers, so your build matches what the motor was tested with.

ESC

BrotherHobby lists a 6S 35 A ESC; its full-throttle peak was 31.5 A. (BrotherHobby test sheet, BrotherHobby parameters)

Props

A 3.5-inch five-blade, the prop BrotherHobby tested it with: 881 g at full throttle on 6S. (BrotherHobby test sheet, BrotherHobby parameters)

Battery

6S. (BrotherHobby test sheet, BrotherHobby parameters)

Frame

Four M2 holes on a 12 mm circle (12 × 12 mm); the shaft takes an M5 prop nut. (BrotherHobby product page, BrotherHobby test sheet)

Where to buy

• BrotherHobbythe maker’s store
  $18.00seen Oct 19, 2026
  Visit

Plain links, not affiliate links. Prices change; the store’s page has the current one.

Full specs

Bench data

Redrawn from BrotherHobby’s test reports. Thrust is static pull on a bench, more than you get in flight. Power is volts × amps; efficiency is thrust divided by power.

Inside the motor

A brushless outrunner: the coils stand still in the middle and the magnets spin around them. From the top down:

• Bell. Hard-anodised 7075 aluminium, φ27 mm, with five broad spokes round a textured hub. (BrotherHobby product page, BrotherHobby test sheet, BrotherHobby materials)
• Shaft. Hollow titanium alloy, 5 mm with an M5 thread, standing 12 mm above the bell. (BrotherHobby product page, BrotherHobby test sheet)
• Magnets. N52H arc magnets, 14 poles. (BrotherHobby product page, BrotherHobby materials)
• Stator. 22 × 5 mm with 12 slots, in 0.2 mm silicon steel, wound with TU1 enamelled wire. (BrotherHobby test sheet, BrotherHobby materials)
• Bearings. Two 8 × 3 × 4 mm bearings, NSK by the spec list, NMB by an infographic. (BrotherHobby product page, BrotherHobby materials)
• Base. 7075 aluminium, with four M2 holes on a 12 mm circle and 20 AWG leads 160 mm long. (BrotherHobby product page, BrotherHobby test sheet)

How fast it spins

KV is the motor’s no-load speed per volt. With nothing on the shaft, the 2140KV version reaches about these speeds; a prop loads the motor and brings it down, typically to around 70–75% of these figures at full throttle.

A 14-pole rotor has 7 pole pairs, so every turn of the shaft is 7 electrical cycles, and a six-step ESC switches the phases 42 times per turn.

About the 3D model

A generic outrunner drawn from BrotherHobby’s published sizes: the 22 × 5 mm stator, 27 mm bell, 15.7 mm height, 5 mm shaft, 12 mm mounting circle and 12 teeth and 14 magnets. Anything BrotherHobby doesn’t publish is typical for a motor this size, and the bell’s spoked top, the base and the inside are a generic design, not this motor’s. The colours are read off the maker’s product photos. There are no logos or markings: it is our drawing, not the maker’s.

Sources

1. BrotherHobby: R3.5 2205 Motor (product page on BrotherHobby’s store, with its spec list, photos and Test Data tab). Retrieved Oct 19, 2026.
2. BrotherHobby: R3.5 2205 2140KV test data, 2020 bench (drawing, spec table and load test on a 3.5-inch five-blade on 6S; image on the Test Data tab). Its spec table gives the motor as φ27 × 32.1 mm; its drawing dimensions 27.7 mm overall.. Retrieved Oct 19, 2026.
3. BrotherHobby: R3.5 2205 introduction and motor parameters, with the 3.5-inch five-blade cinewhoop it is shown on (images on the product page). Retrieved Oct 19, 2026.
4. BrotherHobby: R3.5 2205 exploded view with materials: magnets, bearings, stator steel, winding wire and bell (image on the product page). Retrieved Oct 19, 2026.
5. BrotherHobby: R3.5 2205 thrust and camera-carrying claim (image on the product page). Retrieved Oct 19, 2026.