Infinite Rotators?

Hey, quick question for you more experienced folks out there.

Is it possible to make a rotator spin infinitely in one direction, without it being set to free spin? (In SimplePlanes for example, one could set the rotator's input value to something like Time and it would just spin perpetually in one direction as the input "value" forever increased.)

I'd like to put a rotating beacon on top of my lander so I can see it more easily from a distance, but I'm not sure if there's a way to do that easily or not. (I'm playing in career mode by the way, so without tinker panel shenanigans).

Thanks!