How To Make (Almost) Anything Neil Gershenfeld

MCKENZIE ROSS HUMANN

MIT Department of Urban Studies and Planning

FINAL PROJECT PLANNING

09.14.22

Brainstorming

For years, my husband and I have had worm composting in two home depot buckets stacked on top of each other. But when it comes time to harvest the castings (the finished compost), it's a real pain because we have to dump out all of the worms + worm castings and individually pull out all of the worms... It's fun, but takes a long time!

There are a couple different versions of vermi-compost bins than the one we are currently using. Right now, stackable bins are popular, but still face design issues for usability and worm health. Instead, I want to make a single compartment flow-through (SCFW) vermi-composting bin that is usable inside an apartment.

SCFW bins are often used outside or in barns for industrial sized composting operations (e.g. farms). But the mechanism and design does not necessarily require this large scale to work properly. Instead, the design needs to accommodate enough airflow and ensure an easy process to add food as well as to harvest castings.

While vermi-composting does not need any fancy monitoring, at such a small scale it will be helpful to keep close monitor of moisture-levels and acidity/alkalinity. It could also be interesting to keep track of how much food the worms are able to process over time by weight.

Our current worm composting set up. Two bins stacked on top of each other: the top bin is where all of the action is and has holes at the bottom for leachate to flow into the bottom bin. You can see my harvested castings in the mason jar on the left.

The main components are a top bin where the worms live and feed off of food scraps and paper-products, a harvesting mechanism, and a castings drawer.

The top bin needs to have screens for airflow, an easy open lid, and needs to remain relatively dark.

At the bottom of the composting bin, there is a harvesting mechanism. To harvest the worm-castings, you can roll the rake-like pole that lies on-top of a grate across the grate to loosen up any castings. The castings will then fall down through the grate into the harvesting drawer. The harvesting drawer pulls open and closed and can be used to store castings long-term.