My designs are original and I soon hope to make the product as it is quite cheap and easy to make.
There are numerous uses to this machine, you can not only store things but you can transport heavy cargo, treat it like a remote control car, scare the neighbor kids with it by covering it up with a halloween costume.
As for my designs, here is what the final model looks like
Here is the .123dx file: https://dl.dropboxusercontent.com/u/18723152/a.123dx
There are more pictures on the last step
Step 1: The Chassis
Sorry if gears appear in earlier stages, the program crashed few times
Step 2: Gears
delete all gears except for the second smallest one
duplicate (copy+paste) and move them around.
Step 3: The Motors
I duplicated the altered model and placed it where the motors should go.
Step 4: Battery & Cover Plate
There is also a transparent pvc plate that goes on top of all the motors and holds the battery in place
The pvc plate should be thick so it can handle heavy cargo
As you can notice, I took the liberty to color in the meshes
Step 5: Final Product
The little cones on top are switches that operate the motors, you can also use servo switches (shown in my other instructables)