8- to 10-inch FPV motor
Hobbywing RTF 3115
Hobbywing’s RTF-line 3115 for 8- to 10-inch props, in 900KV and 1050KV; at full throttle on Hobbywing’s 6S bench the 900KV pulls 5177 g on an HQ 10×5×3 and the 1050KV 4420 g on an HQ 9×4×3.
- 8- to 10-inch FPV
- 6S (both KVs, rated 4S–6S)
- 9- and 10-inch props (900KV) or 8- and 9-inch props (1050KV)
The spin is an illustration: the model turns at 1/600 of the no-load speed, and it is a generic 3115 motor drawn from Hobbywing’s published sizes, not its exact design. Thrust, current and power are Hobbywing’s bench figures for the HQ10x5x3 prop at 24 V, read straight across between its throttle steps. Its data starts at 40% throttle.
- Max thrust
- 5,177 g
- HQ10x5x3 prop, 24 V
- Weight
- 125 g
- 1050KV 126 g; Hobbywing does not say whether the leads are included
- Peak current
- 80.9 A
- full throttle
- Max power
- 1,940 W
- full throttle
from $34.99a motor at Hobbywing Direct
A set of four: $139.96
Price seen Oct 19, 2026. Plain links: we earn nothing from them.
What it pulls
Hobbywing’s own bench test, one line per prop. Drag across the chart to move the throttle; the model above follows.
At 60% with the HQ10x5x3: 2,403 g of thrust, 23.0 A, 551 W, 4.36 g per watt.
On your quad
31.9 : 1
Thrust to weight at full throttle: four motors pull 20,708 g with the HQ10x5x3 at 24 V.
At 60% throttle they pull 9,612 g, 14.8 times the quad’s weight.
All-up weight is the quad ready to fly, with its battery and camera. The thrust is the maker’s static bench figure; in the air it is lower.
What you get for $34.99
About 5.2 kg on 6S
At full throttle on Hobbywing’s 24 V bench the 900KV pulled 5177 g on an HQ 10×5×3 at 80.9 A; Hobbywing recommends no more than 9 s at full throttle on that prop.
Source: Hobbywing 900KV spec sheet
Efficiency under load
Hobbywing says the 3115 is about 5% more efficient at high load than same-size motors from other brands.
Source: Hobbywing product page
Cooling rotor
Hobbywing says the rotor’s cooling structure lets it run at full load more than 50% longer than same-size motors from other brands.
Source: Hobbywing product page
Anti-slip prop mount
A grooved prop mount keeps the prop from slipping. Inside are arc-shaped magnets, 0.2 mm silicon-steel laminations and a multi-strand winding of 220 °C wire.
Source: Hobbywing product page
What to pair it with
Our reading of Hobbywing’s numbers, so your build matches what the motor was tested with.
- ESC
- Hobbywing lists its RTF 65A 4-in-1 6S Lite ESCs (BLS V2 or AT), yet its bench runs drew up to 80.9 A (900KV, HQ 10×5×3) and 69.9 A (1050KV, HQ 8×4.5×3) at full throttle; keep full-throttle bursts short on those props or choose an ESC rated above 80 A. (Hobbywing product page, Hobbywing 900KV spec sheet, Hobbywing 1050KV spec sheet)
- Props
- Hobbywing lists the HQ 9×4×3, 9×5×3, 10×4.5×3 and 10×5×3 for the 900KV and the HQ 8×4.5×3 and 9×4×3 for the 1050KV, all on 6S. (Hobbywing product page)
- Battery
- 6S, the voltage Hobbywing benched both KVs at; both are rated 4S–6S. (Hobbywing product page, Hobbywing 900KV spec sheet, Hobbywing 1050KV spec sheet)
- Frame
- Four M3 holes on a 19 mm circle; 16 AWG leads, 300 mm long. (Hobbywing product page)
Where to buy
- Hobbywing Directthe maker's US store; 900KV or 1050KV$34.99seen Oct 19, 2026Visit
- Unmanned Tech900KVprice on the store’s pageVisit
Plain links, not affiliate links. Prices change; the store’s page has the current one.
Full specs
| Spec | Value | Source |
|---|---|---|
| KV | 900 rpm/V (also 1050KV) | Hobbywing product page |
| Stator | 31 × 15 mm (3115) (from the model number; Hobbywing gives no separate stator size) | Hobbywing product page |
| Configuration | 12N14P (12 stator slots, 14 magnet poles) | Hobbywing product page |
| Battery | 4S–6S LiPo (both KVs) | Hobbywing product page |
| Weight | 125 g (1050KV 126 g; Hobbywing does not say whether the leads are included) | Hobbywing product page |
| Dimensions | Φ37.2 × 32 mm (32 mm from the top of the bell to the bottom of the base, which reaches 8.2 mm below the bell (drawing, S4)) | Hobbywing product page, Hobbywing drawing |
| Shaft | 5 mm with an M5 × 0.8 thread, standing 16 mm above the bell; the last 8.5 mm threaded | Hobbywing product page, Hobbywing drawing |
| Mounting | 4 × M3 holes on a 19 mm circle | Hobbywing product page, Hobbywing drawing |
| Bell | Rotor with a cooling structure; grooved, anti-slip prop mount | Hobbywing product page |
| Magnets | Arc-shaped | Hobbywing product page |
| Winding | Multi-strand, enamelled wire rated for 220 °C (C-class insulation) (from the spec sheets; the product page’s table says R class) | Hobbywing 900KV spec sheet, Hobbywing 1050KV spec sheet, Hobbywing product page |
| Internal resistance | 41 mΩ (1050KV 31 mΩ) | Hobbywing product page |
| Idle current | 2 A (at 24 V; 1050KV 2.8 A) | Hobbywing product page |
| Peak current | 81 A (for 10 s; the HQ10x5x3 run reached 80.9 A with 9 s recommended at full load. 1050KV 70 A for 30 s) | Hobbywing product page, Hobbywing 900KV spec sheet |
| Max power | 1,940 W (for 9 s; 1050KV 1675 W for 30 s. Rated output 300 W (1050KV 416 W)) | Hobbywing product page |
| Leads | 16 AWG black silicone wire, 300 mm | Hobbywing product page, Hobbywing drawing |
| In the box | M5 × 0.8 flange nut; M3 × 0.5 cap screws, 13 mm long (drawn with the motor on Hobbywing’s drawing, which gives no quantities) | Hobbywing drawing |
Bench data
Redrawn from Hobbywing’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.
900KV on 4S–6S, 24 V4 props
| Prop | Throttle | Thrust (g) | Current (A) | Power (W) | RPM | Efficiency (g/W) |
|---|---|---|---|---|---|---|
| HQ10x5x3 (HQProp 10 × 5, 3-blade) | 40% | 1,089 | 7.5 | 180 | 6999 | 6.04 |
| 50% | 1,728 | 14.2 | 341 | 8663 | 5.07 | |
| 60% | 2,403 | 23 | 551 | 10072 | 4.36 | |
| 70% | 3,152 | 34.4 | 825 | 11403 | 3.82 | |
| 80% | 4,006 | 49.9 | 1197 | 12713 | 3.35 | |
| 90% | 4,831 | 69.8 | 1674 | 13779 | 2.89 | |
| 100% | 5,177 | 80.9 | 1940 | 14171 | 2.67 | |
| HQ10x4.5x3 (HQProp 10 × 4.5, 3-blade) | 40% | 761 | 5.1 | 124 | 7052 | 6.16 |
| 50% | 1,336 | 10.9 | 262 | 9142 | 5.1 | |
| 60% | 1,871 | 17.5 | 421 | 10582 | 4.44 | |
| 70% | 2,451 | 25.7 | 617 | 11958 | 3.97 | |
| 80% | 3,242 | 37.2 | 894 | 13565 | 3.63 | |
| 90% | 4,181 | 51.7 | 1242 | 14900 | 3.37 | |
| 100% | 4,648 | 61.6 | 1477 | 15606 | 3.15 | |
| HQ9x5x3 (HQProp 9 × 5, 3-blade) | 40% | 784 | 5.4 | 129 | 7106 | 6.06 |
| 50% | 1,263 | 11.1 | 267 | 9016 | 4.74 | |
| 60% | 1,736 | 18.1 | 435 | 10509 | 3.99 | |
| 70% | 2,300 | 27 | 649 | 11932 | 3.54 | |
| 80% | 3,062 | 39 | 935 | 13400 | 3.27 | |
| 90% | 3,910 | 54.3 | 1304 | 14738 | 3 | |
| 100% | 4,279 | 64 | 1535 | 15438 | 2.79 | |
| HQ9x4x3 (HQProp 9 × 4, 3-blade) | 40% | 560 | 3.3 | 80 | 7382 | 6.97 |
| 50% | 937 | 7.4 | 178 | 9556 | 5.25 | |
| 60% | 1,274 | 11.9 | 286 | 11190 | 4.46 | |
| 70% | 1,690 | 17.2 | 414 | 12749 | 4.08 | |
| 80% | 2,327 | 24.7 | 594 | 14398 | 3.92 | |
| 90% | 3,099 | 35.5 | 852 | 16069 | 3.64 | |
| 100% | 3,432 | 41.8 | 1003 | 16934 | 3.42 |
Source: Hobbywing 900KV spec sheet
1050KV on 4S–6S, 24 V2 props
| Prop | Throttle | Thrust (g) | Current (A) | Power (W) | RPM | Efficiency (g/W) |
|---|---|---|---|---|---|---|
| HQ9x4x3 (HQProp 9 × 4, 3-blade) | 40% | 520 | 4.4 | 106 | 8160 | 4.9 |
| 50% | 1,130 | 10 | 240 | 10791 | 4.72 | |
| 60% | 1,773 | 18.3 | 439 | 12676 | 4.04 | |
| 70% | 2,404 | 26.4 | 633 | 14468 | 3.8 | |
| 80% | 3,127 | 37.9 | 910 | 16380 | 3.43 | |
| 90% | 3,931 | 55.2 | 1325 | 17937 | 2.97 | |
| 100% | 4,420 | 64.1 | 1536 | 18874 | 2.88 | |
| HQ8x4.5x3 (HQProp 8 × 4.5, 3-blade) | 40% | 808 | 6.1 | 147 | 8622 | 5.5 |
| 50% | 1,308 | 11.9 | 286 | 10789 | 4.58 | |
| 60% | 1,843 | 19.3 | 463 | 12656 | 3.98 | |
| 70% | 2,448 | 28.9 | 693 | 14452 | 3.53 | |
| 80% | 3,164 | 42.3 | 1016 | 16305 | 3.12 | |
| 90% | 3,916 | 59.1 | 1416 | 17925 | 2.76 | |
| 100% | 4,370 | 69.9 | 1675 | 18729 | 2.61 |
Source: Hobbywing 1050KV spec sheet
Inside the motor
A brushless outrunner: the coils stand still in the middle and the magnets spin around them. From the top down:
- Bell. A rotor with a cooling structure and a grooved prop mount. (Hobbywing product page)
- Stator. 0.2 mm silicon-steel laminations; 12 slots and 14 magnet poles. (Hobbywing product page)
- Winding. Multi-strand winding of enamelled wire rated for 220 °C. (Hobbywing product page, Hobbywing 900KV spec sheet)
- Magnets. Arc-shaped. (Hobbywing product page)
- Shaft. 5 mm with an M5 × 0.8 thread, standing 16 mm above the bell; the last 8.5 mm is threaded. (Hobbywing product page, Hobbywing drawing)
- Base. Four M3 holes on a 19 mm circle; three 16 AWG black silicone leads, 300 mm long. (Hobbywing product page, Hobbywing drawing)
How fast it spins
KV is the motor’s no-load speed per volt. With nothing on the shaft, the 900KV 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.
| Battery | Volts | No-load rpm (KV × V) | Electrical frequency | ESC steps per second |
|---|---|---|---|---|
| 4S nominal | 14.8 | 13,320 | 1,554 Hz | 9,324 |
| 4S full | 16.8 | 15,120 | 1,764 Hz | 10,584 |
| 6S nominal | 22.2 | 19,980 | 2,331 Hz | 13,986 |
| 6S full | 25.2 | 22,680 | 2,646 Hz | 15,876 |
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 Hobbywing’s published sizes: the 31 × 15 mm stator, 37.2 mm bell, 32 mm height, 5 mm shaft, 19 mm mounting circle and 12 teeth and 14 magnets. Anything Hobbywing 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
- Hobbywing: RTF 3110/3115 FPV motors, product page shared by the line (features, a spec table with a column per motor and KV, recommended props and ESCs, downloads). Only the RTF 3115 columns are cited here. Retrieved Oct 19, 2026.
- Hobbywing: RTF-3115 900KV specification sheet (PDF linked from the product page, S1): spec table, load-performance tables at 24 V (6S) on the HQ9x4x3, HQ9x5x3, HQ10x4.5x3 and HQ10x5x3 from 40% to 100% throttle, and the dimension drawing (page 2). Columns as Hobbywing gives them: throttle, thrust, current, input power, rpm, efficiency. Hobbywing’s recommended longest full-load, full-throttle run: 2 min 7 s on the HQ9x4x3, 30 s on the HQ9x5x3, 29 s on the HQ10x4.5x3, 9 s on the HQ10x5x3 (the last given in a column the sheet heads "Temperature"). Retrieved Oct 19, 2026.
- Hobbywing: RTF-3115 1050KV specification sheet (PDF linked from the product page, S1): spec table, load-performance tables at 24 V (6S) on the HQ8x4.5x3 and HQ9x4x3 from 40% to 100% throttle, and the dimension drawing. Columns as Hobbywing gives them: throttle, thrust, current, input power, rpm, efficiency. Hobbywing’s recommended longest full-load, full-throttle run: 30 s on the HQ8x4.5x3, 44 s on the HQ9x4x3. Retrieved Oct 19, 2026.
- Hobbywing: 3115 dimension drawing (PDF, the "3115 CAD" download on the product page, S1). Retrieved Oct 19, 2026.
- Hobbywing: render of the RTF 3115 900KV (image on the product page, S1). Retrieved Oct 19, 2026.
