Please educate me on servos

[GAJ]

specifically, what kills them. By reading posts, I see that servos do die, and that the original HPI servos may not be the best. I have a few dead servos laying around, no gear issues, all electronic related. What is it that dies in the servo, what causes it, and is it repairable?

I have a stock HPI 2.4 radio, no end point adjustments. Am I best to upgrade servos first, or radio first? Should I run good servos with stock radio, or am I putting good money at risk?

Am I correct that if the servos are making noise at the end travel of the throw, they are still trying to move. Therefore wearing them out/damaging them? When I first turn the truck on, the steering chatters a bit until I lift the front and set it back down, is this acceptable?

Thanks

 

[olds97_lss]

Water, too weak for the job, wear.

Probably 90% of the time the gears strip or it gets wet. I could see a servo failing if it was to weak for the job at hand and you were stalling the servo all the time due to linkage adjustment or just not strong enough to work. Also, they do have a little motor in them which over time/use will eventually wear out.

 

[Rolex]

Throttle servos are rarely a problem since they don't have to work very hard to open or close the carb and apply braking. Now, the steering servo is almost always a problem since the manufacturer tries to keep down the cost. Most of us pull that servo out and replace it with one that has lots of power and metal gears. Most stock servos can not move the steering from full left to full right while the truck is on the ground, and that's probably what's causing them to keep trying to reach their end point. The twitch on startup is normal.

 

[olds97_lss]

If you running an MT, the throttle servo does take quite a bit of abuse as far as brakes are concerned. Also, 99% of the time, the t/b servo is standing upright so it's more susceptible to getting water in it down the input shaft. I used to buy the hitec 985MG, but it doesn't exist anymore. Was around pre-digital servos, but was fairly strong and fast (172oz @6V) and it has o-rings on the output shaft, case halves and case screws. I run one in all 3 of my MT's for t/b and in one of them (big block revo), I also use one for steering. Have had all three for many years and they work fine still.

I have a hitec waterproof HS-5646WP in my 1/8th buggy for steering just as a trial. It does ok, but I doubt I'd use it on an MT for steering. It would probaly be strong enough for t/b though. I think I have a traxxas high torque 2075 Digital for t/b on it. I use the same 2075 Digital for both steering and t/b on my jato. I'm only using the traxxas ones because they are waterproof, strong enough for the jobs I'm using them for and cheap to buy on ebay. They are plastic output shaft and gears though, so they aren't the strongest.

 

[Rolex]

it's more susceptible to getting water in it down the input shaft.

Who runs in water? I don't even run in dust. I've never had a problem with carpet lint in my servos.

 

[olds97_lss]

Who runs in water? I don't even run in dust. I've never had a problem with carpet lint in my servos.

Your probably the exception. Then again, taking them into the bath with you is probably hard on the servos. So you may want to upgrade too.

 

[GAJ]

Thanks guys.

 

[Rolex]

taking them into the bath with you is probably hard on the servos.

LMAO! You have a point there.