HS-77BB Low Profile Servo

Part No: 31077S

Product Description

With its low profile design and strong standing torque, the HS-77BB is a great choice for wing or tail mounting in aircrafts up to 1.20 size. Submarines, boats, cars and trucks can also benefit from this servo’s strength and compact size.


  • Low Profile Compact Design
  • High Torque Three-Pole Ferrite Motor
  • Durable Nylon Gears
  • Top Ball Bearings

Related Products (Right Column)

Programmer (if applicable), Gears Set, 1st Gear set (if applicable), Case Set, Applicable horns and mounting hardware.

Downloads (Button Below Charts)

2D Drawings, output shaft 2D drawing, available horns 2D drawings

Programmable Functions

List of programmable features and interface type

HS-77BB Servo Specifications

Performance Specifications Min. Max. Unit
Operating Voltage Range 4.8 6 V
Speed 0.18 0.14 Sec @ 60º
Maximum Torque 61 76 oz / in
4.4 5.5 kg / cm
Current Draw at Idle -- 8 mAh
No Load Operating Current Draw -- 250 mAh
Stall Current -- 800 mAh


Physical Specifications   Unit
Dimensions (W x D x H) 1.73 0.90 0.98 in
44.0 23.0


Weight 1.23 g
35.0 oz
Motor Type 3 Pole Metal Brush Ferrite --
Gear Material Nylon --
Bearing Type Top Ball Bearing --
Output Shaft STD 24 --
Dust Resistance IP 63 --
Water Resistance N / A --
Control Wire Gauge / Strand Count 25 / 40 AWG