| 48KG·CM STALL | 0.090S/60° NO-LOAD | 16.8V RATED |
| 69G WEIGHT | StainlessGEARTRAIN | 360°TRAVELCustomizable |
Overview
The BLS348HV is the high-voltage build of the 48 kg·cm low-profile servo: same 41 × 20.5 × 28.5 mm case and 69 g as the BLS348, rated for 4S packs. At 16.8 V it delivers 48 kg·cm at 0.09 s/60°; at 8.4 V the same servo is a 30 kg·cm unit.
The geartrain is stainless steel on two ball bearings with a 25T-φ5.96 mm spline and a POM horn. There is no mechanical stop on the output, and the case is a CNC aluminium block with fins cut into the sides rather than a plastic shell.
This page covers the PWM build: a standard 50–333 Hz pulse input, 1500 µs neutral and a 3–4 µs dead band. It is the version to pick when the servo hangs off a receiver or a flight controller and you want nothing between the two.
Performance at each supply voltage
| Supply | No-load speed | Peak stall torque | Idle current | Stall current |
|---|---|---|---|---|
| 8.4 V | 0.140 s/60° (429 °/s) | 30 kg·cm (2.94 N·m / 417 oz·in) | 190 mA | 3.5 A |
| 12 V | 0.110 s/60° (545 °/s) | 37 kg·cm (3.63 N·m / 514 oz·in) | 220 mA | 4 A |
| 16.8 V | 0.090 s/60° (667 °/s) | 48 kg·cm (4.71 N·m / 667 oz·in) | 250 mA | 5 A |
Control specification
| Item | Specification |
|---|---|
| Command signal | PWM |
| Amplifier | Digital controller |
| Pulse width range | 800–2200 µs |
| Neutral position | 1500 µs |
| Dead band | 2 µs |
| Rotating direction | CCW (1000–2000 µs) |
| Travel | 360°, customizable |
Mechanical specification
| Item | Specification | Item | Specification |
|---|---|---|---|
| Dimensions | 41 × 20.5 × 28.5 mm | Case material | Aluminium, CNC |
| Weight | 69 g | Geartrain | Stainless steel |
| Bearings | 2 × ball bearing | Motor | Brushless |
| Output spline | 25T-φ5.96 mm | Horn | Plastic, POM |
| Lead / connector | 300 mm, 3-wire | Mechanical limit | No limit |
| Operating temperature | −15 °C to 65 °C | Storage temperature | −20 °C to 70 °C |
| Ingress protection | Splash resistant (customizable) | Travel | 360°, customizable |
What’s in the box
- 1 × XQ-BLS348HV servo
- 1 × POM horn set
- 1 × mounting screw pack
Optional: metal horn, sold separately.
How to size it
Torque follows the rail: 30 kg·cm at 8.4 V, 37 at 12 V and 48 at 16.8 V. If the machine runs 4S, size the linkage at 48; if it is a 3S machine, this servo will behave like a 37 kg·cm unit and the standard BLS348 is the cheaper match.
Stall current is 5 A at 16.8 V against 250 mA no-load. On a 4S pack a BEC that also feeds four of these sees 20 A at stall — check the BEC before blaming the servo for brownouts.
FAQ
What is the difference between the BLS348 and the BLS348HV?
The winding. The HV build is rated to 16.8 V and gives 48 kg·cm there; the standard BLS348 reaches 48 kg·cm at 8.4 V. Same case, same geartrain, same 25T spline.
Can it run on 2S?
Yes, but you are leaving torque on the table: at 8.4 V it is a 30 kg·cm servo at 0.14 s/60°.
What pulse range does it accept?
The inspection sheet specifies a 500–2500 µs window (800–2200 µs on the 9130/9150) with 1500 µs neutral, both customizable at order. Feeding it outside that window is out of spec.
Can I drive it from a normal receiver?
Signal-wise yes, but check the supply. This servo wants 8.4–16.8 V, not a 6 V receiver pack, so the power rail has to be separate from the receiver’s.
Downloads
- XQ-BLS348HV inspection specification (PDF, 662 KB)
Torque, speed and current at each supply voltage, mechanical data, control specification, mounting dimensions. - 2D dimension drawing (image)
Mounting hole positions, case depth and overall height; the same drawing is inside the datasheet.
