1S tiny whoop motor
HappyModel RS0802
A 2 g motor with a 1.5 mm shaft on an 8 × 2 mm stator, made for the 1S versions of HappyModel's Mobula7; 34.8 g of thrust per motor on HappyModel's 3.7 V bench (20000KV, Gemfan 1610).
- Mobula7 and Mobula7 HD, 1S versions
- Mobula7 Freestyle HD
- 1S only
The spin is an illustration: the model turns at 1/600 of the no-load speed, and it is a generic 0802 motor drawn from HappyModel’s published sizes, not its exact design. No-load speed is KV × 3.7 V, a nominal pack for this version. HappyModel’s bench tables for it step by thrust rather than throttle, so they are in the bench data below, not on this readout.
- Weight
- 2 g
Plain links: we earn nothing from them.
What you get
1.5 mm shaft
HappyModel fits a 1.5 mm shaft to this 8 × 2 mm motor.
Source: HappyModel product page
2 g
HappyModel lists 2 g per motor.
Source: HappyModel product page
For the 1S Mobula7
HappyModel lists it for the Mobula7 and Mobula7 HD 1S versions and the Mobula7 Freestyle HD.
Source: HappyModel product page
Bench data
34.8 g at 3.74 A on 3.7 V with a Gemfan 1610 two-blade prop (20000KV).
Source: HappyModel product page
What to pair it with
Our reading of HappyModel’s numbers, so your build matches what the motor was tested with.
- ESC
- HappyModel's 20000KV table tops out at 3.74 A per motor (3.7 V, Gemfan 1610). A 1S whoop board rated 5 A per motor covers it. (HappyModel product page)
- Props
- HappyModel tested it with the Gemfan 1610 two-blade. (HappyModel product page)
- Battery
- 1S LiPo only. (HappyModel product page)
- Connector
- A JST 1.25 mm plug on 30 mm leads. (HappyModel product page)
Where to buy
- RaceDayQuads20000KV, choose versionprice on the store’s pageVisit
- GetFPV20000KV, CCWprice 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 | 20,000 rpm/V (also 25000KV) | HappyModel product page |
| Stator | 8 × 2 mm (0802) | HappyModel product page |
| Configuration | 9N12P (9 stator slots, 12 magnet poles) | HappyModel product page |
| Battery | 1S LiPo only (both KVs) | HappyModel product page |
| Weight | 2 g | HappyModel product page |
| Dimensions | Φ10.5 × 13.5 mm | HappyModel product page |
| Shaft | 1.5 mm | HappyModel product page |
| No-load current | 0.46 A (20000KV at 2 V) | HappyModel product page |
| Peak current (bench) | 3.74 A (where HappyModel's 20000KV bench tops out: Gemfan 1610 two-blade at 3.7 V) | HappyModel product page |
| Max power (bench) | 13.838 W (same row as the peak current) | HappyModel product page |
| Leads | 3 leads, 30 mm without the plug, ending in a JST 1.25 mm plug | HappyModel product page |
Bench data
Redrawn from HappyModel’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.
20000KV on 1S, 3.7 V1 prop
| Prop | Step | Current (A) | Thrust (g) | Efficiency (g/W) | Power (W) |
|---|---|---|---|---|---|
| Gemfan 1610 (2-blade) | 0.5 | 6.1 | 3.297 | 1.85 | |
| 1 | 11.3 | 3.054 | 3.7 | ||
| 1.5 | 15.9 | 2.865 | 5.55 | ||
| 2 | 20.8 | 2.811 | 7.4 | ||
| 2.5 | 24.7 | 2.67 | 9.25 | ||
| 3 | 29.4 | 2.649 | 11.1 | ||
| 3.5 | 32.5 | 2.51 | 12.95 | ||
| 3.74 | 34.8 | 2.515 | 13.838 |
Source: HappyModel product page
Inside the motor
A brushless outrunner: the coils stand still in the middle and the magnets spin around them. From the top down:
- Shaft. 1.5 mm. (HappyModel product page)
- Stator. The coils are wound on a stack of thin steel laminations: 8 × 2 mm (0802). (HappyModel product page)
How fast it spins
KV is the motor’s no-load speed per volt. With nothing on the shaft, the 20000KV 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 | 296,000 | 29,600 Hz | 177,600 |
| 4S full | 16.8 | 336,000 | 33,600 Hz | 201,600 |
| 6S nominal | 22.2 | 444,000 | 44,400 Hz | 266,400 |
| 6S full | 25.2 | 504,000 | 50,400 Hz | 302,400 |
A 12-pole rotor has 6 pole pairs, so every turn of the shaft is 6 electrical cycles, and a six-step ESC switches the phases 36 times per turn.
About the 3D model
A generic outrunner drawn from HappyModel’s published sizes: the 8 × 2 mm stator, 10.5 mm bell, 1.5 mm shaft and 9 teeth and 12 magnets. Anything HappyModel 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
- HappyModel: RS0802 KV20000 KV25000 new series brushless motor for Mobula7 1S (product page, spec list and bench data). Retrieved Oct 19, 2026.
- HappyModel: RS0802 main product photo, used for finish. Retrieved Oct 19, 2026.
