I'd like tubes for the motor wiring
to travel inside of

Just a thought, Tim.

Several years ago we needed some very light, thin and very flexible
wire to connect sensors on the pick-up-head of an old pick-and-place
machine. The wire was subject to a lot of torque as the head rotated
to the correct theta to place the part. Original wire was unobtanium.

I found a source of two conductor litz wire on Ebay. It was from
England and was for hi-fi record pick-up heads. I think I ordered it
from them a couple of times. It had one copper wire and one gold wire.
The copper was insulated and the gold was twisted around the copper.
The guy sold it by the meter and a meter was good for a couple of
years for us. Something like this would power your fan motor and not
add much weight to the arm. I am sure this will be a question in the
near future .

Paul