Newbie looking to run two 8.4v servos with Arduino

Using Arduino Motors, Mechanics, Power and CNC
1

Greetings to all,

I'm looking to run a simple program such as "sweep" with two 8.4v servos:

-I am using an Arduino Uno, powered via usb from a computer which is connected to a power strip.

-The 8.0v is provided to the servos by a BEC that is also plugged into the same power strip.

-The signal wire to the servo is connected to pin 9 on the Arduino Uno

Attempting to run the "sweep" with the large servos doesn't work. If I connect a smaller servo it works. The smaller servo has a signal wire connected to pin 9, and the power and ground is connected to the Arduino Uno 5v power and ground.

Any advice would be greatly appreciated.

2

Is the negative from the 8.0V servo supply connected to the Arduino ground?

What is the current rating of the 8.0V BEC? The servos have a stall current of around 6A so it should be at least that much.

Steve

3

My BEC can support up to 12.0A

However, I did not connect the negative to Arduino ground. Will try!