Its taken a few months but finally got the head of the Tuxedo cat moving automatically with a Zene Bricks motor off an inbuilt powerbank.
The power bank was problematic. I had a couple of years old ones from Lidl. One fitted perfectly but transpired not to be powerful enough. The other was too big and I incorrectly assumed it would be simple to find one that fitted.
Eventually realised the wider one I had was too wide by the thickness of the case on one side. One side cut off and the power bank then slid into the top part of the body
It is accessible for charging via the hinged part of the body.
Made USB leads I found were too bulky. A bare usb plug used to form the connection from the power bank. As this power bank automatically switches on once it is connected an on off switch was immediately incorporated. The switch being fitted to a modified 1x4x1 panel with M2 plastic bolts and nuts, and then glued to the 2x 8 Techic plate with holes fitted at step 310 so that is also accessible through the hinged part of the body.
Via a connector then come 3 electronic modules: a power bank keep alive, a radio control on off switch and a timer. The timer is linked to via the Zene Bricks connector to the motor.
The modules with suitable insulation slipped over two of them fitted into a vertical opening inside the body.
The timer module is giving the shortest of ouputs meaning the head is turning only very slightly and then there is a wait of nearly 2 minutes before a further movement.
The radio control on off switch allows for a remote operation without having lift the hinged part of the body to operate the on off switch beyond the initial switch on, and final switch off.