I am in the process of connecting up 18 Tower Pro SG90 servos to a Pololu Mini Maestro 24 controller to complete my build of a Plen 2 (Custom redesigned to fit the above servos and allow space to carry the controller).
I am using an adjustable power supply that has voltages of 3, 4.5, 6, 7.5, 9 and 12vdc. The label says that the output is 300mA 3.6 VA max. I am suspicious this could be my problem detailed below.
If I add the servos one at a time (I do this whilst the board is connected to USB and PSU) they all initialise to the correct position as detailed in the Pololu controller software. I have successfully got up to 7 or 8 servos connected and done a restart to reset positions. If I add any more the legs just cave in and go into a kind of spasm with one leg going straight and the other curling up and the servos buzzing. At that point I disconnect power and USB and move the servos manually to the correct position then try power again but still get same result. PICTURE ATTACHED.
I suspect that this may be a PSU issue. Possibly not enough milliamps. Can anyone advise what power supply rating I would need if indeed this is the problem?
Forgot to add that the voltage I have set the PSU to is 6vdc.
A link to the Plen robot is below
A link to the servos is below
A link to the controller is below
All advice is greatfully accepted.