Tools // Component Selector // SunnySky
SunnySky X4125
hobby uav brushless motor. Specs read from manufacturer page ↗.
advertised This thrust figure is the one the vendor advertises, read from their product copy. The throttle setting, propeller and cell count behind it are frequently unstated, so it is a guide rather than a measurement.
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Specifications
| Brand | SunnySky |
|---|---|
| Model | X4125 |
| Stator | 4125 |
| Weight | 351 g |
| Max thrust | 8,148 g |
| Max current | 90.0 A |
| Max power | 2,250 W |
| Peak power | 2,351 W |
| No-load current | 1.40 A |
| Winding resistance | 0.021 Ω |
| Max RPM | 8,891 |
| Hover efficiency | 5.46 g/W |
| Peak-throttle efficiency | 3.46 g/W |
| Grade | hobby |
| Application | uav |
| Data confidence | reported |
| Thrust basis | reported |
| Efficiency basis | reported |
| Measured test points | 17 |
Measured thrust curve
Where to buy
| Vendor | Price | As listed | Stock | Lead days | |
|---|---|---|---|---|---|
| SunnySky USA US | A$172.43 | USD 119.99 | in stock | 12 | buy ↗ |
| SunnySky USA US | A$172.43 | USD 119.99 | in stock | 12 | buy ↗ |
| SunnySky USA US | A$172.43 | USD 119.99 | in stock | 12 | buy ↗ |
| SunnySky USA US | A$172.43 | USD 119.99 | in stock | 12 | buy ↗ |
Multi-pack listings are shown at their per-unit price so they stay comparable.
Thrust test points
| Propeller | Cells | Thrust g | g/W | Basis |
|---|---|---|---|---|
| unspecified | — | 8,148 | 3.46 | reported |
| unspecified | — | 6,959 | 3.94 | reported |
| unspecified | — | 5,991 | 4.31 | reported |
| unspecified | — | 5,058 | 4.73 | reported |
| unspecified | — | 3,980 | 5.46 | reported |
| unspecified | — | 3,493 | 5.80 | reported |
| unspecified | — | 3,074 | 6.19 | reported |
| unspecified | — | 2,752 | 6.49 | reported |
| unspecified | — | 2,527 | 6.72 | reported |
| unspecified | — | 2,317 | 6.99 | reported |
| unspecified | — | 2,043 | 7.32 | reported |
| unspecified | — | 1,724 | 7.96 | reported |
| unspecified | — | 1,504 | 8.36 | reported |
| unspecified | — | 1,274 | 8.86 | reported |
| unspecified | — | 964 | 9.96 | reported |
| unspecified | — | 741 | 10.54 | reported |
| unspecified | — | 540 | 11.27 | reported |
Compatible accessories
Parts this catalogue holds that fit this component, and the evidence behind each pairing. Fit is inferred from published specifications, not from having tried it. Confirm mounting and clearance before you buy.
rule of thumb The size conventionally run on a stator this big. Not a measurement -- check clearance and current draw before flying it.
| Accessory | Type | From |
|---|---|---|
| APC Propellers 18x10 propeller | propeller | A$20.00 |
| APC Propellers 18x5.5 propeller | propeller | A$24.00 |
| APC Propellers 18x8 propeller | propeller | A$26.00 |
| Xoar 18x10 propeller | propeller | A$37.00 |
| Xoar 18x6 propeller | propeller | A$37.00 |
| Xoar 18x8 propeller | propeller | A$44.00 |
| Master Airscrew 18x10 propeller | propeller | A$47.00 |
| Master Airscrew 18x8 propeller | propeller | A$47.00 |
| Master Airscrew 18x6 propeller | propeller | A$47.00 |
| Master Airscrew 18x12 propeller | propeller | A$47.00 |
| APC Propellers 18x12 propeller | propeller | A$49.00 |
| Xoar 18x13 propeller | propeller | A$53.00 |
CAD model
No CAD model linked yet.
How the metrics are calculated
TWR is max thrust divided by motor weight, motor only, static, excluding propeller and ESC. EFTWR scales that by hover efficiency and RPM headroom, so it equals TWR for a motor at 8 g/W and 10,000 RPM. Full methodology and the whole catalogue →