| 48KG·CM STALL | 0.090S/60° NO-LOAD | 8.4V RATED |
| 69G WEIGHT | StainlessGEARTRAIN | 360°TRAVELCustomizable |
Overview
The BLS348 is the 48 kg·cm member of the low-profile brushless family: the same 41 × 20.5 × 28.5 mm case as the BLS325, 4 g heavier at 69 g, and nearly double the torque. Same mounting holes, same 25T spline, same 20.5 mm profile.
Going from 25 to 48 kg·cm in the same envelope is a gear-ratio and motor-wind change, and you pay for it in speed: 0.09 s/60° at 8.4 V against 0.07 s/60° on the 325. For 1/10-scale steering or a large control surface that is the right trade; for a fast cyclic load it may not be.
This page covers the TTL build: the same mechanics, commanded over a serial bus so several servos can share one signal line and be addressed individually. Useful when the actuator count outgrows the PWM channels available.
Performance at each supply voltage
| Supply | No-load speed | Peak stall torque | Idle current | Stall current |
|---|---|---|---|---|
| 6.0 V | 0.140 s/60° (429 °/s) | 30 kg·cm (2.94 N·m / 417 oz·in) | 190 mA | 3.5 A |
| 7.4 V | 0.110 s/60° (545 °/s) | 37 kg·cm (3.63 N·m / 514 oz·in) | 220 mA | 4 A |
| 8.4 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 | TTL serial |
| Amplifier | Digital controller |
| 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-BLS348TTL servo
- 1 × POM horn set
- 1 × mounting screw pack
Optional: metal horn, sold separately.
How to size it
48 kg·cm at 8.4 V is the headline; on 7.4 V it is 37 kg·cm and on 6.0 V it is 30 kg·cm. With 5 A stall current at the top rail, two of these on one BEC will pull 10 A at stall — size the BEC for the transient, not the average.
Because the case is the same as the 325’s, the mounting and the clearance are identical. If you are replacing a 325 with a 348 for more torque, nothing in the bracket changes; if you are replacing a 348 with a 325, you lose 23 kg·cm and gain 0.02 s/60°.
FAQ
What is the difference between the BLS325 and BLS348?
Torque and speed: 48 kg·cm at 0.09 s/60° against 25 kg·cm at 0.07 s/60°, same 41 × 20.5 × 28.5 mm case, 69 g against 65 g.
Is the case really the same?
Yes. The 348 shares the 41 × 20.5 × 28.5 mm housing and the 49 mm mounting span with the 325, so brackets and clearance are interchangeable.
Is the pulse width table valid for this unit?
No. The microsecond window printed on the inspection sheet belongs to the PWM build of the same servo. This unit is commanded over the serial bus — ask for the command set and register map before writing firmware.
How many can share one bus?
The limit is the address space and the current budget of the shared supply, not the signal pair. Keep the bus ground common with the power ground at a single point.
Other interfaces
Downloads
- XQ-BLS348TTL inspection specification (PDF, 419 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.
