Max Servo Wire Length

How far can I place a servo from the servo controller?

I’d like to use the “Serial 8-server controller” to open and close dampers on my HVAC system. Some of the dampers may be as far as 20 feet from the controller. Will this work?

I suspect the answer isn’t a simple yes/no, but rather depends on the cable used and possibly the servos in question. Any guidelines or suggestions will be appreciated. (Could I use cat-5 cable to supply signal and power to a servo 20’ away?)


I have used regular servo wire… about 5 meters long.
which is about 15 feet without any problem.
I have tested on 5 different Hitec servo and futaba.

I don’t think you have a problem if you use less than 8 meters (24 feet) any longer you may need a servo cable booster. They are pretty cheap not too expensive.

I built a servo robot a few years ago with a 20-foot-ish tether using standard ribbon cable for the signal lines, and common power/ground bus. Everything worked great while the controller was turned on, but when the servos were powered and the controller was off, the servos tended to pick up phantom signals and twitch or drive themselves to extremes, which at one point damaged the body of the robot.

You’re also going to start to notice a voltage drop across your length of wire, but the larger diameter the wire, the less of a voltage drop you will see. I would guess that 22 gauge shielded cat-5 cable would do just fine, and be impervious to environmental interference, but you should try and see.


Hi nexisnet

Do you remember which servo you used?

We switched the kind of servos we were using at some point, and I forget if it was before or after building this robot, but it used either the FMA Premire Series metal gear servos (more likely) or the Hitec HS-645mg.