Hi Jim,

The slip ring seems to be a method to transfer current to a rotating element, overcoming the twisting of the cables, is that so ? Ten cables go to the motor ? So many leads,  merely for redundancy, no other purpose ? A small motor doesn't draw a lot of wattage, does it ? How big is this whole assembly ? The two pins attached to the motor connect with the driving wheel is made by you for the purpose I assume. Is the weight of the display wholly borne by the three tyred wheels ? 
You made this whole assembly in a hurry, did you manage to get a business to hire it ? Well done.
Regards,
Gus

Keep Safe