I want to build a RC control 2 motor set which can be attached to 2 wheels a large frame such as a baby stroller/shopping cart and can carry weight of 30 kilograms and move at variable speeds of approximately 20kmph. No axle needs to be built.
Have a look at the attached page and video, it shows what I want to build. [login to view URL]
I will source the parts for you online once you specify what would be required to build a larger version of what is shown on the page mentioned above
In my college days I designed a bot for Robowars, where wheel dia is important factor for motor selection then electronic components for that motor controller unit so first specify wheel dia then I'll give motor specs like speed and torque then controller components