Pedal Base
Concept
The pedal base is just a mechanical gain platform for me to attach other tools to.
Design
I currently have to competing designs
Bike Base
Buy a cheap bike (salvage or craigslist) and take off the front and use the back wheel as the drive. For this I would add concrete to the spokes of the wheel to act as a flywheel.
Belt Drive
I could also make one myself out of wood using belt drives. This is mechanically much simpler, but slightly less efficient.