And by "en-masse", I mean roughly enough to be able to chew through enough fruit to easily give me 2-3 gallons of juice.

I understand cooking the fruit down will also yield more juice, but for products such as "fresh-squeezed" orange juice or lemonade, doing such a thing isnt as ideal seeing that it would partly take away from its "freshness".

We have tried two mechanical citrus juicers - the kind with a pull down arm like a slot machine. The arm broke off from both after a few weeks. Now we just don't juice.

Here is a link that might be useful: The type which broke