DSSERVO BLS3325 All-Metal Brushless Digital Servo, 25kg Class

Description

BLS3325 brushless servo by DSSERVO is an all-metal digital servo in the 25 kg·cm class, intended for RC cars and robotics. The matching manufacturer datasheet lists 26 kg·cm stall torque at 7.4 V and 30 kg·cm at 8.4 V. Stall torque is a locked-shaft specification, not a continuous-load rating.

All-metal construction and IP67 rating

The manufacturer identifies the BLS3325 as an all-metal brushless servo with double bearings and IP67 waterproof performance. Product images show a stainless-steel gear train, an aluminum middle shell and waterproof gaskets. IP67 is the stated rating for the servo; protect the connector and cable entry in the installed system and do not assume the complete vehicle or robot is waterproof.

Torque, speed and current by voltage

The stated operating range is 4.8–8.4 V. At 8.4 V the listed stall current is 6.2 A, so use a receiver BEC or regulated supply sized for expected load and current peaks. Do not power the servo from a microcontroller GPIO pin. No-load speed is measured without mechanical load, and prolonged locked-shaft operation can overheat the servo or power system.

Dimensions and mounting

The matching BLS3325 datasheet lists a 40 × 20 × 38 mm body, 85 g net servo weight, 183:1 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 45.5 mm maximum height including the output spline. Check the drawing against your mounting holes, enclosure clearance and horn spline before ordering.

Mount the servo tabs without distorting the case and align the horn and linkage before applying load. Adjust controller endpoints so the linkage does not bind or force the output against a mechanical stop.

PWM control and wiring

The BLS3325 uses PWM position control with a 500–2500 µs pulse range, 1500 µs neutral position, 2 µs deadband and a listed 50–330 Hz operating frequency. The manufacturer diagram shows 180° or 270° travel over the pulse range; actual travel depends on configuration and controller endpoints. The datasheet lists counterclockwise rotation for the stated pulse range. Verify direction and travel with the linkage unloaded before installation.

The wiring illustration shows a JR-style 3-pin, 2.54 mm connector. The pictured cable versions use brown or black for ground, red for positive supply, and orange or white for signal. Confirm connector polarity before applying power; wire colors can vary by production version.

Applications and setup

The product graphic lists 1:8, 1:10 and 1:12 RC cars, as well as robotics. Choose the servo based on actual steering or joint load, horn length, geometry, power capacity and travel rather than the 25 kg class label alone. For setup, test direction and endpoints with the mechanism unloaded and leave clearance at both travel limits.

Package contents

The BLS3325 supplier quotation lists one BLS3325 digital metal servo, one 25T adjustable metal servo arm and one accessory set as pictured. It does not enumerate each accessory or quantity. Confirm a particular screw, horn style or quantity before purchase if it is essential to your build.

Frequently asked questions

What does the 25 kg class refer to? The product is marketed in the 25 kg·cm class. The matching datasheet lists 26 kg·cm at 7.4 V and 30 kg·cm at 8.4 V under stall conditions.

Is it compatible with 8.4 V? Yes. The datasheet lists a 4.8–8.4 V operating range; at 8.4 V it lists 30 kg·cm stall torque and 6.2 A stall current.

Does IP67 rate the whole RC car or robot? No. IP67 is the stated servo rating. The installation, cable entry and other electronics need their own protection.

Does the servo always move through 180° or 270°? The diagram shows both control ranges. Actual travel depends on servo configuration and controller pulse endpoints.