Servo Life

[Andrew McKelvey 1]

How long should a servo last?
 

I have read a number of old posts to try and find an answer but most seem about how to test, do you use a tester or radio but my question is this.

 

You are doing your preflight check and your aileron servo is a bit jittery, never was in the past so you abort flying today until you check it out but you think back that plane is 15 years old and the servos are the same age, it is an easy job to stick a new servo in but not nessesarily of the same type, but what of the old servo, I have in the past stripped a servo down given it a spray with electrical cleaner around the pot and brought it back from death..would you trust it.

 

Also I swapped a servo of a different brand into a wing the other day of my glider, not really thinking much about it, but same orientation horn on the same side and did a preflight check and it rotates in a different direction than the original, never seen it before. Have I just been lucky?

[ken anderson.]

suppose the thing is ...is it worth trying to revive a servo that has the ' Jitters' and risk using it in a model which has cost you a few bob....could be false economy.

 

ken anderson...ne...1...throw it away dept.

[Geoff S]

I'd only use a 'revived' servo for a non-critical application like on-bench testing or perhaps a parachute drop control that wouldn't affect flight. 

[J D 8 - Moderator]

 I have some servos still in service much older than 15. If they are not misbehaving let them be. Other wise it is by by, already old after all.

  What radio are you using? Just a case of needing to needing to program "reverse" in for that channel? 

 

[Andrew McKelvey 1]

Futaba on FASTT, 6Ex, 7C 8FG, I think it was the y lead because I put the servo on the tester and it was perfect, sprayed contact cleaner on the terminals of the lead and tested using radio and no sign of glitching, even flown it this afternoon with no issue.

[Andy Gates]

Could just be a dirty connection in the Y lead so removing and replugging the servo back in effectively wipes the contact surfaces.

[Robin Colbourne]

To try and put a figure on this is ignoring all the different factors which could affect the life of a servo.
 

• How has it been stored?  In a warm, dry, heated house or a damp garage or shed exposed to wide variations of temperature and humidity?
• How has it been used?  In an IC model exposed to engine vibrations, an electric model with minimal vibration or a glider with no vibration.
• How many abrupt arrivals has it had?
• Was it mounted correctly on its anti-vibration mounts and were the brass ferrules the right way up?
• Has the wire been tugged at the pug or circuit board, weakening the solder joints?
• Was it on a throttle so the potentiometer brush was usually at the ends of its travel, plus random points inbetween, or on a control surface with the brush at the mid-point most of the time?
• How hard was it having to work when in use?

[Brian Cooper]

There is no definitive lifespan for a servo. Some last longer than others depending on each individual servo and the application it has been employed to do. . Some have a harder life than others. 

 

However, in the grand scheme of things, servos are not hugely expensive. So while it can be inconvenient to have to replace them, it does at least give peace of mind. 

 

It is arguably best to treat servos as a "consumable" item, rather like tyres on a car. 

They don't last forever and when they wear out, or become "moody", they should be replaced. 

 

 

 

[PatMc]

I agree with Brian but add that if the servo is one of a pair I'd replace both, since they will have had the same wear & tear.