Juicing without electrical power can be done with a heavy duty hand operated hydraulic floor or shop press. As an example, these are sold by Harbor Freight Tools, (800) 423-2567. They range from 6, 12 and 20 ton sizes and prices from $70, $120 to $230. They are floor mounted and weigh 62, 112 and 200 lbs respectively. There are often on sale in their stores for much less. One would need to build or purchase several stainless steel plates or small cooking pans (one to fit inside the other) to press the juice between. These two thin plates are used with a slightly smaller size but thicker steel backing plates. This is so the thin stainless doesn't bend. A drain in the lower stainless plate would allow the juice to run into a container as the two plates or pans are pressed together. The lower plate or pan needs to have some low sides to it to guide the liquid to one outlet. I plan to juice grass and weeds using this approach when electricity is not available. It is also, good for juicing herb plants (roots included) for medicinal purpose. I recommend going for the 20 ton one if you can afford it.
Offered by Mike.
I began to think about the possibility of using an old hydraulic cylinder as the vessel. Clean it up take off the retainer at the piston end for easy placement of the food to be juiced into the cylinder, then use your operating press cylinder to squash the contents of the lower cylinder. Most of these cylinders are stainless inside and there is a hole at the lower end that would have been used to operate the cylinder in the opposite direction for draining out the liquid. if you didn't have an operating hydraulic cylinder you could simply set up a lever system to push in the piston, sort of like a giant garlic press.
Offered by Michael.