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Technical Specifications
Last Updated: 2026-09-13Disclaimer: Most data is sourced from the manufacturer. Some data is sourced from our loyal community and with the help of AI. We aim for accuracy but are not responsible for inaccurate information.
Class Comparison
| Torque | Average Stronger than 53% of 75 Analog Mini servos at 4.8V |
| Speed | Above Average Faster than 80% of 75 Analog Mini servos at 4.8V |
| Weight | Above Average Lighter than 69% of 155 Analog Mini servos |
| Running Current | Average Lower draw than 47% of 50 Mini servos at 4.8V |
| Stall Current | Below Average Lower draw than 19% of 27 Analog Mini servos |
Performance Analysis
| Shaft Power | 0.61–0.86 W |
| Power Density | 1.353 W/in³ More power-dense than 85% of 153 Analog Mini servos |
| Torque Density | 2.1687 oz-in/g Stronger than 64% of 75 Analog Mini servos |
| Torque-to-Volume Ratio | 56.44 oz-in/in³ Denser torque than 61% of 75 Analog Mini servos |
| Speed-to-Weight | 0.54765 (1/sec·g) Faster than 70% of 75 Analog Mini servos |
| Speed-Torque Trade-off | 3.96 Better balanced than 32% of 75 Analog Mini servos |
| Current-per-Torque Ratio | 0.0417 A/oz-in More efficient than 13% of 81 Hitec servos |
| Idle-to-Running Current Ratio | 0.041 Lower idle draw than 47% of 61 Hitec servos |
| No-Load vs Stall Current Spread | 6.82 Narrower current spread than 51% of 56 Hitec servos |
| Torque Gain per Volt | 13.89%/V More voltage-responsive (torque) than 50% of 55 Analog Mini servos |
| Speed Gain per Volt | 18.52%/V More voltage-responsive (speed) than 67% of 55 Analog Mini servos |
| Voltage Range Width | 1.2 V Wider voltage range than 77% of 85 Analog Mini servos |
| Dead-Band-to-Pulse-Width Ratio | 0.0067 Finer dead band than 11% of 20 Analog Mini servos |
Notes
This servo comes in a metal gear version that has been discontinued, HS-81MG.
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Reviews (21)
Includes 17 reviews aggregated from around the web.
There are few reviews for this servo on the web. Buyers describe good price-performance and consistent quality for park flyers, small helicopters and tight installs. Nylon gears are a durability limit under shocks.
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wally
June 17, 2016Application(s): 1500mm warbird
Comments: These are cheap so i guess you get what you pay for. The gears strip easily. Had a crash and both ailerin servos striped.
Trick Wings, Zagi
February 4, 2014Application(s): The HS-80 and later the HS-81 has been used for elevon servos in the Zagi THL and all of the electric flying wings for 15 years.
Comments: The way we rate servos is by service, availability and price. The HS-81 rates high for our mixed elevon application. Very few returns or user issues. It's a reliable servo.
Gary Parker
January 13, 2012Application(s): Mid-size power planes and gliders
Comments: I have been disappointed by these servos. Sure, they are cheap, but they develop slop, and they strip easily. Hitec HS-85MGs are the same size but are far stronger and better. But then again, 85s cost around twice as much.
RocketGuy
November 7, 2009Application(s): Elevon control, CombatWings MiniXE (100mph 34"flying wing)
Comments: A solid well modulated servo. Quick, precise, and crash resistant. Very impressive for a micro servo. I frequently had roll rates exceeding 600deg/sec and yet was able to instinctively enter level flight at will.
