BrotherHobby R3.5 2205
| Stator | 2205 |
|---|---|
| KV options | 2140 |
| Weight | 27.18 g |
| Shaft | 5mm |
| Max cells | 6S |
| Configuration | 12N14P |
| Dimensions | Ø27x32.1 mm |
| Mount (bolt circle, mm) | Ø12 (4-M2) |
| Winding resistance | 87.00 mOhm |
| Max thrust | 881 g |
| Price (approx.) | 21.99 USD |
Thrust data (BrotherHobby bench test)
| KV | Prop | Battery | Throttle | Current | RPM | Thrust | Efficiency |
|---|---|---|---|---|---|---|---|
| 2140 | 3.5 inch Five Blade | 6S | 30 | 2.9 A | 15618 | 184 g | 2.52 g/W |
| 2140 | 3.5 inch Five Blade | 6S | 40 | 5.8 A | 20283 | 281 g | 1.92 g/W |
| 2140 | 3.5 inch Five Blade | 6S | 50 | 9.7 A | 24836 | 406 g | 1.66 g/W |
| 2140 | 3.5 inch Five Blade | 6S | 60 | 12.6 A | 27376 | 479 g | 1.51 g/W |
| 2140 | 3.5 inch Five Blade | 6S | 70 | 16.8 A | 30117 | 569 g | 1.35 g/W |
| 2140 | 3.5 inch Five Blade | 6S | 80 | 26.0 A | 35461 | 766 g | 1.18 g/W |
| 2140 | 3.5 inch Five Blade | 6S | 90 | 31.0 A | 37479 | 850 g | 1.1 g/W |
| 2140 | 3.5 inch Five Blade | 6S | 100 | 31.5 A | 38249 | 881 g | 1.12 g/W |
Manufacturer bench figures (BrotherHobby 2020 bench, 2140 KV at 6S (25.2 V), 6S 35 A ESC, 8 throttle points (30-100%) on one 3.5 inch five-blade prop); real-world thrust varies with ESC, battery sag and prop condition.
R3.5 2205 vs other 2205 motors on 6S
The same thrust costs different power on different motors. Each line is one maker's own bench series (6S, its own prop), drawn as grams of thrust per watt against thrust, so a higher line makes that thrust for less battery current. Throttle percent is left out on purpose: it means something different on every maker's rig.
| Motor | KV | Prop | Peak thrust | At 850 g | |
|---|---|---|---|---|---|
| BrotherHobby R3.5 2205 | 2140 | 3.5 inch Five Blade | 881 g at 788 W | 775 W (1.1 g/W) | |
| iFlight Xing 2205 | 2450 | HQ 4*3*3 | 1458 g at 910 W | 406 W (2.1 g/W) |
Power at 850 g is read off each maker's curve, straight-line between its two nearest bench points; 850 g is the highest thrust every motor here reached. Different props and rigs move these curves as much as the motor does, so compare rows on a similar prop. How to read a bench table: reading motor bench tables.
Thrust-to-weight with this motor
Four BrotherHobby R3.5 2205 motors at 881 g max thrust each give 3524 g: 2:1, the minimum to fly, up to 1762 g all-up; 4:1 (freestyle) up to 881 g; 8:1 (racing) up to 440.5 g.
RPM & prop speed on this motor
Props in this motor's class
| Prop | Size | Blades | Weight |
|---|---|---|---|
| Gemfan Long Range 5126-2 Durable 1.5mm T-Mount | 5.1x2.7 | 2 | 2.6 g |
| HQProp DP 5.1x2.5x3 | 5.1x2.5 | 3 | 3.1 g |
| HQProp Juicy J37 | 4.9x3.7 | 3 | 3.4 g |
| HQProp Juicy J40 | 5.1x4.0 | 3 | 3.4 g |
| Gemfan 4935 Sbang 3-Blade | 4.9x3.5 | 3 | 3.45 g |
Where this data comes from
The 881 g is the 100% row of BrotherHobby's own R3.5 2205-2140KV Test Data table, read 2026-09-27 off the product page's Test Data tab: eight throttle points at 25.0-25.2 V, 787.50 W and 31.50 A at full throttle, which are the Specification block's Max power and Max Current to the digit. 87.00 mOhm, 0.9A/10V idle, 20# 160 mm leads, 4-M2 on a Ø12 pattern; copper wire 106 degC after 2 min at 100% throttle, 26 degC ambient