I successfully got one to move by tricking it with a flashlight.
Before the lights came on, I set a flashlight on the glass lid directly over the top of the rbta. After about 15 min I moved the flashlight so it was over the edge of the rbta's disk in the direction I wanted it to move.
Sure enough, got it to move right where I wanted about 2" to the left.
Note: this was done about a week after adding the nem.