Another alternative to create driving shots resp. moved backplates and spheres is this up to 4m long camerarail.

The fast connection system of the 1m sections enables any desired length for even long exposure runs.

Precise speed of the sledge is guaranteed by the motor control. To avoid unnecessary retouch, a cameraboom can be attached to the sledge.
The whole Rail weighs approx. 28kg and fits in a box with 1,15m length.