This short video shows a very simple way to motorize a tripod track dolly using friction between two wheels. In the video below i've modded the Cinerails Snaptrack kit.
The main parts are a simple DC motor and Speed Controller from Servo City, and small venom 11V 3S Lipo battery. I mounted the Speed Controller up top so I don't need to bend over to change speed or direction. I mounted the motor just over one of the track wheels, and used washers to get the right amount of spacing.
Unfortunately these were spare parts laying around my house, so I don't have the exact part numbers. While I work on getting that together, here's a few links to get you started. I'm sure If you contact ServoCity.com they can probably help you out with an entire kit.
This looks like a fun project. David Sawyer has modified an electric trike to perform long tracking shots with a few DSLR or GoPro cameras hard mounted [Thanks David]. The agility of the electric three wheeler allows for some very tight maneuvering and interesting camera footage.
Here's a look at some images David has shared with his modified Three Wheel Electric Trike.
The Electric Trike David uses is of course a more expensive high end version with a front electric hub, but if you're looking for a cheaper Electric Trike Scooter solution about $350 bucks, there is a stand-up TRX electric scooter that should have no problems mounting a few small cameras to it. That's about the price of a Canon 50mm F/1.4 lens, check out the item below.
Thanks to YouTube member dim3m for sending in this fine example of a modified Pico Flex Dolly. [Thanks dim3m] The rear trailer contains the servo, servo controller, batteries, etc. The laser alignment shows you the cross point reference for the center of rotation. Having motorized control gives you more consistent movement across the entire rotation. Aside from fancy rotating shots, the Pico Flex can mimic side to side slider shots, or push / pull dolly shots. Especially useful for B-Roll, cut away, or pick up shots with small product reviews. For more information on the Pico Flex Skater Table Dolly check out PhotographyandCinema.com.