I shoot quite a few motion timelapses. I started out with a telescope motor which was cool but ended up breaking and was limited to daytime stuff with short exposures. If you try to shoot stuff at night the motion is too much for the shutter speed and you end up with blurs. This goes for dollies and pan/tilts. I worked for a company that bought me a mumford timemachine/sherline motor setup for a project. It looks kind ghetto with cords running everywhere but works awesome. The controller acts as your intervalometer for your camera and also tells the motor when to move. So the move happens, it rests for a second, it tells your camera to fire and so on. So you could be shooting a 5 minute star exposure in the middle of the night with absolutely no bluring. I use the motor on a tripod and on a ladder dolly I made. The setups aren't cheap though, the motor and controller are about 1400 bucks I think.