Using a 12v DC motor and a 12v acid battery, Joakim Fjedli built a nice automatic pull for his slider. String pulls the camera from one side of the slider to the other. He used a voltage controller to adjust speeds. It takes 8 minutes at 12v and 16 minutes at 6v. This seems to work really well with timelapses. He features a beautiful one in the video. A pretty nice DIY solution for a motorized slider.
Thanks to DIY Photographer for the story.