Hacked HX12K servo - erratic behaviour.

Hi, I’m new to this forum and am a novice when it comes to electronics in general.

I acquired a remote controlled tank that my uncle put together using a radio receiver and 2 hacked hex Teck HX12K servos. I am trying to instead run these servos off of an arduino UNO instead on the radio receiver. The problem I am having is that the servos run erratically as soon as the myservo.attach() executes. The servos will begin to spin in one direction, hold still for a moment and spin in reverse for random duration’s and in a random order.

I’ve tried to write to the servos using the myservo.write() command with various values and tried to use capacitors and a pot to find the null position but, alas, get the same result. there doesn’t appear to be any pattern to the movements and my google search has yielded no solution.

I know the servos can work as they respond to the remote control as expected. If it is of any use, the radio receiver is a HK60F 6 channel receiver, and the servos are powered independently via a transformer connected to the mains set to 6V.

Could anyone possibly shed some light on what the issue could be? any direction would be immensely appreciated.

Many thanks.

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