After some improvements the timelapse dolly is more stable now. Due to the four wheel steering it can run in very small circles and with the differential it brings the power to the wheels correctly. By exchanging some of the cogwheels it is possible to change the speed of the dolly. From very slow to veeeeerry verry slow. I got it from 10cm in 3 minutes to 10cm in 2 hours.
I am very surprised by the batteries. I am using regular AA batteries and they are lasting for more than 8 hours of constant driving right now.
Hopefully I find the time in the near future to make some timelapses that show the advantages of this rail-less dolly a little better.
how to build: vimeo.com/37669400
more Lego crazyness: Lego filming gear