We got one of the fancy ones just for convenience. The stacking ones use the worms natural hatred of light to help separate them from their castings when you’re ready to use it. Several use three trays. You start with one, and add the second and then the third as the trays fill up. When full, you take the bottom one and put it on top without the lid. The worms wil move down into the lower trays to escape the light. After a couple days, the worms will have moved down and you can dump it in your garden or make potting soil. Put the tray back on top with the lid on and fill it up again, then repeat. You can definitely make something similar with a few old plastic bins.
