Hello,

I bought an old e-revo that came without a servo, and I finally received the servo today.
I plugged everything in, the servo seems to be working normally when it has nothing connected to it, but when I connect the servo horn it doesn't really work (I works more or less if I hold the car in the air, but impossible to move when the tires hit the ground).
When looking at the servo horn (after trying to turn with the car on the floor) the screw turns but not the servo horn.
I don't want to break anything, should I really tightened the screw fast, use another servo horn, servo arm??
Here is what it looks like now :

http://www.hostingpics.net/viewer.ph...977IMG1953.jpg

It is my first non rtr car, and don't really know what to do

I am using a Hitec HS 7955TG on a e-revo 4s Orion R8 and no BEC.
Also the servo is making a lot of noise (I heard that a Buzzing sound is normal) but it really sounds like a "bad sound".


Thanks very much for your help

If you can see the screw turning but not the horn, it sounds like the servo horn is stripped out. With the wheels off the ground there is not much resistance for the servo so even a worn servo horn would possibly grab. Get an aluminum one.

The horn should have splines on the inside of it. If there is none or the splines are to many, you'll have to find the proper insert that matches how many splines your servo has. Most new horns come with 3 other inserts numbered with 23, 24, and 25 splines. Find the one that fits your servo. Perhaps a fellow racer/hobby shop could help you with this. The sound you hear is probably the servo splines stripping inside the horn.

Thanks for the advices guys!!

So I also have this bag of parts that came with the servo :

http://www.hostingpics.net/viewer.ph...314IMG1954.jpg

Am I supposed to build something with these parts?
And replace the entire Revo "turning system"?

No manual came with the Servo

A majority of the things pictured there are generic and can be gotten rid of. The disc horn, the double-sided horns, the screws and the brass sleeves can all go away. It's just stuff that is put in with a servo so it can be used in pretty much any scenario (planes, cars, etc).

You should take the servo and horn (or the whole truck if you rather) to your local hobby shop and have them match something up for you. Just looking at the pictures, I don't think you have anything on hand that will help your situation.

Thanks !!
I think I found the solution though, I used a nut with the Aluminium horn and it seems to be working just fine.
Only things that worries me is that the horn was very hard to put on the servo, I pressed quite a lot and it didn't go all the way, hope it will hold on, didn't wanted to break it ;(

The aluminum horn should have a number stamped on it somewhere in the long arm, backside? 23, 24, etc. You may have missed the proper one by one spline and that's why it went on part way and hard. Have to find out how many splines are on the servo. If you purchased it new, there should be some info. on it in the pkg.

Wish Servo Database included spline counts. Would be a great addition to a useful site.

Don't sound right, I would def look into geting the right one or it will cost u more in the long run if u screw sumn else up!

HiTec servos are a 24t horn. Also, HiTec servos make noise, nothing to be concerned about, but adding a BEC should make the noise a little bit quiter.