| 54KG·CM STALL | 0.108S/60° NO-LOAD | 8.4V RATED |
| 81G WEIGHT | StainlessGEARTRAIN | 360°TRAVELCustomizable |
Overview
The S8050TTL is the largest in this series with a serial command layer: 54 kg·cm at 0.108 s/60°, 81 g, 20 × 40 × 41 mm, addressed over a TTL bus instead of driven by a pulse train. Mechanically it is the S8050D — same motor, geartrain, spline and case height.
The 41 mm case is the one dimension that changes against the rest of the family, and on a bus-driven machine it matters twice: you are usually fitting several servos into the same structure, so a 2.6 mm difference compounds across the assembly.
Performance at each supply voltage
| Supply | No-load speed | Peak stall torque | Idle current | Stall current |
|---|---|---|---|---|
| 6.0 V | 0.158 s/60° (380 °/s) | 41 kg·cm (4.02 N·m / 569 oz·in) | 350 mA | 4.4 A |
| 7.4 V | 0.132 s/60° (455 °/s) | 47 kg·cm (4.61 N·m / 653 oz·in) | 390 mA | 5.4 A |
| 8.4 V | 0.108 s/60° (556 °/s) | 54 kg·cm (5.30 N·m / 750 oz·in) | 450 mA | 6.2 A |
Control specification
| Item | Specification |
|---|---|
| Command signal | TTL serial (addressed over a bus) |
| Amplifier | Digital controller |
| Dead band | 1 µs |
| Rotating direction | CCW (1000–2000 µs) |
| Travel | 360°, customizable |
Mechanical specification
| Item | Specification | Item | Specification |
|---|---|---|---|
| Dimensions | 20 × 40 × 41 mm | Case material | CNC aluminium |
| Weight | 81 g | Geartrain | Stainless steel |
| Bearings | 2 × ball bearing | Motor | Coreless |
| Output spline | 25T / 5.94 mm | Horn in box | POM plastic |
| Lead | 300 mm | Travel limit | 360°, customizable |
| Operating temperature | −15 °C to 65 °C | Storage temperature | −20 °C to 70 °C |
| Ingress protection | Splash resistant (customizable) |
What’s in the box
- 1 × XQ-S8050TTL servo
- 1 × POM horn set
- 1 × mounting screw pack
Optional: metal horn, sold separately.
How to size it
Torque budget = load at the horn × horn length from spline centre × 1.5 safety factor.
Worked example: an 8.5 kg surface with its centre of pressure 35 mm from the spline centre needs 8.5 × 9.81 × 0.035 × 1.5 ≈ 4.38 N·m. The S8050TTL delivers 5.30 N·m at 8.4 V, about 21% headroom. On a bus with several nodes, budget the supply for the sum of the stall currents (6.2 A here) rather than the sum of the idle currents.
FAQ
What command set does it use?
TTL serial with a factory-fixed frame. Request the command set before integrating; the physical layer is not the protocol, so do not assume Modbus.
Can it share a bus with the smaller models?
Yes. The S8035TTL, S8045TTL and S8050TTL are individually addressable on the same multi-drop bus, which is the usual way to build one assembly with mixed torque requirements.
Can I drive it from a normal receiver?
No. Use the XQ-S8050D if your controller only outputs a pulse train — same 54 kg·cm, same case, PWM input.
Will it fit where an S8045TTL fits?
Footprint and spline yes; height no. The case is 41 mm against 38.4 mm, so check clearance above the servo rather than the mounting pattern.
Can I run it directly from a 2S LiPo?
Yes. 8.4 V at full charge is the top rail in the sheet and the rail the 54 kg·cm figure is measured at. Stall current at that rail is 6.2 A.
Does it rotate continuously?
Travel is 360° when commanded over 1000–2000 µs, as a factory customization. On the serial build the same range is commanded over the bus.
How much is 54 kg·cm in oz·in?
About 750 oz·in, or 5.30 N·m.
Downloads
- XQ-S8050TTL inspection specification (PDF, 857 KB)
Torque, speed and current at 6.0 / 7.4 / 8.4 V, mechanical data, control specification, mounting dimensions. - 2D dimension drawing (image)
Quick view of mounting hole positions and case depth; the same drawing is inside the datasheet.
