Why do my servos keep frying?
 

I just fried a JR 9100 servo on my throttle. This is the second servo in the past couple months granted the first one was poor quality. Anyway, I saw smoke coming from the servo seconds before it died. It got stuck at 3/4 throttle so i had the pleasure of chasing my car around the track before smashing it into a wall :flaming: to finally get a hold of it. Now on my controller the throttle servo setting it set to "reverse" could this be a possible cause for burning this servo out? (the reverse setting on my controller allows for the servo to function is its normal manner) Also, i did not have to use the reverse setting until i bound my controller to another car. (this car has steering, throttle and aux all in the normal positions). Thanks for reading.

What car is this in, what kind of radio you using, and have you adjusted your endpoints?

could be to much brake epa or just a bad batch of servos like i had with hitec with centering the cheaper ones, do u use a lipo as a reciver battey

I use the spektrum receiver and had a similar problem a couple years back. The problem was with the receiver. I had a JR9000T for steering, and it fried. I replaced it with a brand new 9000T and it also went poof in less than 1 tank. Frustrated, I replaced the receiver with another new one and the problem went away and I haven't replaced another servo since. If you have the opprotunity to change out the receiver, I'd try that as well. I had all my end points set, so it wasn't a end point issue. Even after I replaced the receiver, I didn't change the end points cause it was still good. Hope this helps. btw, the receiver I had last almost a year and a half in my LSP. To me, it was a decent life span for a large scale nitro vehicle that I used twice a week for almost the entire duration.

I am running a losi 8ight 2.0 with spektrum dx3s controller. I did make some adjustments to my endpoints, but I cannot confirm i adjusted them correctly as I am still fairly new to all this.

losi servo death machine strikes again!

sorry to hear it man. Horizon has good customer service. i just sent a 9100 in recently and they replaced it 100% free. good luck

Check and make sure the throttle servo is not hitting the mud guard. I had to shave down the guard on my 2.0. I went through 6 servos when I first got the 2.0 until a losi team driver pointed it out to me. Check it out and I bet it's hitting the side mud guard.

To set you end points especially on the 8 take off your filter assembly and pull full throttle start backing of the end point untill you have a small amount closed. What i do for brake may be different for others but I start the car and run it full bore and start putting end point where the tires lock up on pavement. That is enought brake for me.

When you adjust your throttle, you want to adjust the end point while you are pulling full throttle, set your epa around 50% throttle, and with your airfilter off, see how far that opens your carb. If it opens all the way, then check to see if the carb is pulling on the motor and putting tension on it. If it is, then you lower your epa. If the slide carb is not fully opened, then increase the percentage until it opens all the way. After you have it open all the way, make sure the motor is not being pulled by the carb and servo at full throttle. You want the slide to open, but not to pull the entire motor. The easiest way to see it is if you put the truck on your starter box or something pretty solid. Pull the throttle and see if the cooling head moves. If it does, then you have too much throttle. If it stays put, then you are set. If you are just starting out and the track is pretty tame, lower you throttle epa so that the vehicle is more controllable. The only time you would want to have full power is if you have jumps where you need full power to clear. If this is the case, then you will need to learn throttle control while you learn to drive.

For the brakes, you don't want a full lock setup. You can either do this with the car running or not. I like to have the car running, drive it around and then at throttle, try to bring your car to a stop. It should not lock up your tires wildly. If you lock your tires up, then you may want to reduce the brake epa so that the vehicle comes to a little more controlled stop. This is easier on the servo and the car and makes it a little easier to drive.

Good luck and I hope this helps.

Once you learn how to properly set EPA, invest in a pair of Hitec 7955, 7950, or 7940 servos and you'll be good for the next... 10 years!!!! :smile:

Yup, everyone has their personal favorites. I used to run JR's but I really like the Hitec series alot. Plus hitec's customer service is top notch as well. JR's are good in my book, but the Hitecs are a little better spec wise and warranty wise as well. But these are just my opinion.

Thanks for all the replies, especially gotspeed_2000 concerning the setting of the endpoints. Frank L, you were right, the servo is contacting the mud guard :mad: wish I would have had a little more attention to detail, oh well, guess you gotta learn.

if your buggy is set correctly you the buggy should not cause the servos to burn.... now what i have found drive LOSI for the last couple years is that I was buring servos not from the tray or chassis fault but my linkage was set wrong...... got that fixed and running hitec servos - no more DNFs because of servos...........

The spring on the throttle arm should not be compressed all the way.....

I had a 2.0B....my tx epa's and carb linkage setup was dialed and checked by all the fast guys at my track and I still managed to lose a HiTec 5955.

Hey Frank, how could you tell it was rubbing? I tried to look but I couldn't quite see. How much did you shave off?