DSSERVO BLS3225 Brushless Digital Servo, 25kg Class

Description

BLS3225 brushless servo by DSSERVO is a 25kg-class high-speed digital servo for RC vehicle steering and robotics projects. The manufacturer datasheet lists stall torque up to 25 kg·cm at 8.4 V. The 25kg model class is the top-voltage stall rating; torque and speed change with operating voltage.

Brushless motor, metal gear train and IP67 rating

The BLS3225 uses a brushless motor and a stainless-steel gear train, with double bearings, waterproof gaskets and a CNC aluminum middle shell shown in the product images. The manufacturer datasheet identifies IP67 waterproof performance. This listing reports the stated rating and does not extend it to conditions beyond the manufacturer’s product information. Keep the connector and cable entry protected in the installed system.

Torque, speed and current by voltage

The allowed operating range in the datasheet is 4.8–8.4 V. At 8.4 V, the listed stall current is 6.2 A, so choose a receiver BEC or regulated supply capable of handling the expected load and current peaks. Do not power this servo from a microcontroller GPIO pin. Stall torque and stall current are locked-shaft figures; the no-load speed values are measured without an applied mechanical load and are not continuous-load guarantees.

Dimensions and mounting

The manufacturer datasheet lists a 40 × 20 × 37.5 mm body, 60 g net servo weight, 175:1 gear ratio, double bearings and a 300 ± 5 mm connector lead. The dimension drawing shows 54.5 mm overall mounting-tab width, a 49.5 mm mounting reference and a 42.5 mm maximum height including the output spline. Use the technical drawings to check mounting-hole spacing, spline clearance and available enclosure space before ordering. Confirm the servo horn fits the output spline and that the linkage can move without binding.

The supplied product illustration identifies a stainless-steel output gear, precision steel gears, aluminum middle shell, waterproof gaskets, bearings and top and bottom covers. Secure the mounting tabs without distorting the case. Correct horn alignment and linkage geometry help prevent mechanical overload and excess current draw.

PWM control and wiring

The BLS3225 uses PWM position control with a 500–2500 µs pulse range, 1500 µs neutral position, 2 µs deadband and a listed operating frequency of 50–330 Hz. The manufacturer diagram shows 180° or 270° travel over the pulse range. Actual travel depends on servo configuration and controller endpoints, so verify the required movement before attaching the horn to a constrained steering or robot joint. The datasheet lists counterclockwise rotation when using the 500–2500 µs control range.

The connector image identifies a JR-style 3-pin, 2.54 mm connector. For the cable versions illustrated, brown or black is ground, red is positive supply, and orange or white is signal. Wire colors can vary between production batches; follow the product wiring diagram and confirm pin polarity before applying power. Reversed polarity may damage the servo or connected electronics.

Typical uses and setup

The product graphic names 1:8, 1:10 and 1:12 RC cars as target applications. This brushless servo may also suit robotics projects where its dimensions, voltage range, torque, speed, spline and control travel match the design. Check the load at the servo horn rather than selecting by the 25kg class label alone. Vehicle mass, tire grip and steering geometry affect RC steering loads; arm length and payload affect robot-joint torque.

For initial setup, use a supply within the 4.8–8.4 V range and test direction and endpoints with the linkage disconnected or mechanism unloaded. Adjust the controller so the linkage does not push against a mechanical stop. The high stall-current figures make power capacity important, particularly when several servos share a receiver supply. Avoid prolonged locked-shaft operation.

Package contents

The BLS3225 supplier quotation lists one BLS3225 digital metal servo, one 25T adjustable metal servo arm and one accessory set as pictured. The quotation does not enumerate each accessory or its quantity. The product images show several horn shapes and mounting parts; confirm a particular screw, arm style or quantity before purchase if it is essential to your build.

Frequently asked questions

Is the BLS3225 a 25 kg·cm servo at every voltage? No. The datasheet lists 15 kg·cm at 4.8 V, 22 kg·cm at 7.4 V and 25 kg·cm at 8.4 V under stall conditions.

What is the 7.4 V speed? The listed no-load speed is 0.055 sec/60° at 7.4 V. Actual movement speed depends on load and the power system.

Is it a brushless servo? Yes. The manufacturer datasheet identifies the motor as brushless.

Does 180° or 270° travel work automatically? The diagram shows both control options. Actual travel depends on the servo configuration and controller pulse endpoints; check the mechanism before use.