siku john deere wheels have stopped self centreing

[thomas]

hi   , do you know why the wheels would stop self centreing on this rc tractor .

thanks 

[RC Tractor Guy]

Are they locking hard to one side or jittering and shaking?

If you use it quite a bit the first thing to check is dirt on the rack and pinion or if the servo wire has come loose from the control board which might result in noise but unlikely. More likely is a problem internal to the servo, either the gearing is worn/dirty or there is a problem with the potentiometer.

To test, take the tractor apart and hold the servo free from the tractor then operate the steering, you say it self centered before so if the problem is in the servo it wont self center when free from the rack, if it does self center then the problem isn't in the servo. Let me how you get on with that.

[thomas]

Hi I took it apart but still the same . Why is there four wires going to these servos , any servos I have worked with before only have three thanks

[RC Tractor Guy]

Oh that is strange alright, I would guess that two wires are the motor and two are some sort of encoder. What does the main control board look like? Can you see where the PCB traces go and if they go to a chip can you see any identifying numbers?

You might just have to chance taking the servo apart and looking for signs of wear or dirt making it hard for the motor to turn.

By the way did you know you can order some replacement parts from the website here www.siku.de/en/shop/sikuparts/2/sikucontrol32.html

[Bill]

Hi Thomas,
Have you found out why there is 4 wires to the servo?