Steering trim problem

[Destroyer]

Hello!

I've just got a new Slash VXL 4x4. After playing less than hour and no serious crashes the car's steering became strange: there is no matter if I turn the steering wheel left or right and then release it - the wheels do not go back to zero position, they may look left or right. And every time it is different. I try to ajust zero position with steering trim, it works, but after using steering wheel ones more - zero position is gone.

It is not a machanical problem, because I see how servo works, servo saver works fine it is not loosen or screwed. The problem is - every time I release steering wheel servo stops at different position. I guess that I need to setup something in TX or RX to solve this problem?

My car is new out of the box, I don't think that I need to replace something.
For better explanation I made a small video:

Zero position is impossible, it is unstable. If I manage to set it, even little hand touch of steering wheels make servo turn wheels right or left (.
That is the problem.
I've already done a TX reset to factory defaults.

Any advice is appreciated, thanks.

[50togo]

My friend had the same type of problem changed the servo to a hitec and no problems since

[Destroyer]

Thanks for the reply. Do you mean servo motor 2080 from this chassis assembly (http://traxxas.com/explodedviews/700...-Slash-4X4-VXL) ?
To my mind servo motor is ok, because it is working, but VXL-3m Electronic Speed Control gives it wrong commands. Is there any way to check it?
Can anyone tell or give a link to the theory of servo control (a suppose there is no angle encoder and it is a step motor)?

[joe831]

I have the same problem, makes lining up jumps very annoying. I think it is because the wheels have play or slop. See for yourself, you can wiggle the wheels in your hand right? Many different things contribute to this.

[Destroyer]

To my mind slop and wiggle of wheels do not influence on servo at all. Servo must stay at zero position no matter what happens to wheels (for example the car runs over the stone).
Still need help with this problem.

[50togo]

Try replacing the servo saver

[joe831]

Think about it this way: if the wheels have slop then even with the servo pointed straight ahead 0*, the wheels could be pointing anywhere from say -5* to 5*. If the wheels are straight ahead 0*, then you turn left 45*, then when you return the servo to 0* to wheels will stay at 5*, they wont come all the way back to 0*. Same if you turn left -45*, then release to bring them back to 0*, the wheels might only come back to -5*. Sorry if it's hard to understand, but that's what I concluded. I have the exact same problem, and I have an aftermarket ESC, an aftermarket servo, an aftermarket TX, and an aftermarket RX. I was also going crazy uselessly adjusting the trim. Yes slop does not influence the servo at all, but even if the servo does return to center, the wheels do not, and you will not be able to drive straight.

[Destroyer]

joe831, I understand what you are saing ). You are telling about playing steering parts, but if you saw my video, servo doesn't come back to zero. For successive steering first of all servo must come back to zero.
It seems that servo's potentiometer is bad.
Can I replace this potentiometer (where can I get it)? Or I can replace only the whole servo (what model)?

Thanks.

[joe831]

Oh, sorry, you are right. I didn't see the video. Seems your servo is definitely messed up. Almost everyone on here reports problems with the stock servo at some point. I would upgrade it, a favored choice on here is the ******* 390. It is what I run. I believe its metal geared and stronger, but its not waterproof out of the box.

Sent from my DROID4 using Tapatalk

[50togo]

Back to what I said with my friends servo!

[Petertje60]

Seems like a servo failure. But it might aswell be the transmitter or receiver. If you throttle works good, you could try to swap the servo and ESC plugs in the receiver. If the servo works normal on the throttle signal, you can rule out the servo.
You can also try to reset the transmitter.