Blue Bird BMS-125WV+ Servo – 7.1Kg.cm 0.09s 11.3g 10mm

The Blue Bird BMS-125WV+ is the highest torque servo in the new Blue Bird BMS-125WV+/126WV+/127WV+ range of 11g servos. At 8.4V the torque of the BMS-125WV+ is a massive 7.1 kg.cm. The speed is lower than the other servos in the range but is still 0.09 seconds per 60° of movement, which is fine for 99% of models. It is suitable for all control surfaces on lighter F5J models and most gliders up to 4 m wingspan. At 10 mm thick it is suitable for mounting in small fuselages and thin wings and tails.

The WV in the name stands for Wide Voltage, indicating that this servo has wide range of acceptable supply voltages and is suitable for 1S LiPo, 4 or 5 cell NiMH and 2S LiPo operation.

The + plus moniker on these servos is to indicate this version is an upgrade on the BMS-125WV we previously sold. Some of the photos still show the BMS-125WV as apart from the label the new servo looks identical.

The Blue Bird BMS-125HV+ is a great servo built to the same space saving form factor as the MKS DS6100 and MKS HV6100. It is similarly precise, with no free play in the geartrain, and it is much more powerful and faster than the competing products. The large output spline is identical to Futaba 25 tooth splines, so replacement output arms are readily available. Note the output spline is not the same as MKS so the servo cannot be used with most MKS accessories.

Although it looks like the BMS-105HV the BMS-125 WV+ uses new components, better bearings and an improved internal design and does not suffer the longevity problems that affected some high hours BMS-105 installations.

Blue Bird BMS-125WV+ Servo Specifications
Body dimensions	23.2 mm wide x 10.0 mm thick x 23.0 mm high	0.91″ wide x 0.39″ thick x 0.91″ high
Max dimensions	32.0 mm wide x 10.0 mm thick x 25.0 mm high	1.26″ wide x 0.39″ thick x 0.98″ high
Stall torque (3.7V)	3.6 Kg.cm	50 oz.in
Stall torque (6V)	5.5 Kg.cm	76 oz.in
Stall torque (8.4V)	7.1 Kg.cm	99 oz.in
Weight	11.3 g	0.40 oz
Lead length	16 cm	6.3 in
Operating speed (3.7V)	0.2 sec/60°
Operating speed (6V)	0.13 sec/60°
Operating speed (8.4V)	0.09 sec/60°
Operating voltage	3.5V to 8.4V
Operating temperature	0 to 40 °C
Bearings	2 ball bearings
Gear material	Metal alloy
Case material	Nylon
Motor type	Coreless DC motor
Working frequency	250 Hz
Dead band/resolution	2 µs
Pulse width for ± 60º	(L) 900 µs – (0°) 1520 µs- (R) 2100 µs
Digital	Yes
Programmable	No
Position feedback	Potentiometer
Supplied accessories	2 plastic output arms, 1 arm retaining screw, 4 mounting screws, Blue Bird sticker
Optional accessories	Ply Frame for BMS-125WV, Integrated Drive System/Mono for the Blue Bird BMS-125WV, Frame with bearing for the Blue Bird BMS-125WV