I haven’t been too happy with our worm bins. (From Magic Worm Ranch). The drain seems to stop up, the worms don’t seem to thrive, and harvesting the worm castings takes an hour or so of manually fishing out worms.
After looking around, I bought a Worm Factory from Composters.com. It’s a five bin tower. You keep putting kitchen scraps and roughage (shredded paper for us) into the top bin. Hopefully by the time you get all five bins filled the worms have finished with everything yummy in the bottom bin, and moved on. So you empty the bottom bin and make it the top. Meanhile, there’s a reservoir with a spigot in the base, which accumulates the worm tea.