Pick a scale that matches planned throughput. General hardware rules—ramps, drainage, aeration, shelter—are in the tank design article. Build steps and bills of materials live with each design, not duplicated here. Format policy (SVG, CSV, OpenSCAD—not proprietary CAD as source of truth).
Scale glossary
- Lid kit — BSF-5G-LID: largest hinged sub-lid the stock lip lid allows (molded handles opposite the hinge; kitchen collection and rack modules share it).
- Collection bucket — intact 5-gal shell (no drain/harvest holes) + lid kit; kitchen / route pickup; dumps at the hub.
- Rack bucket — BSF-5G-RACK: drilled process shell (low-corner drains, side/upper aeration (off bottom curve when tilted), adult ports under 1 cm, near-rim threaded harvest) + lid kit; sits in a cradle.
- Bank — one modular rack assembly (e.g.
BANK-5G-8= 24 rack buckets, ~19 kg/day mid). - Municipal — many banks plus logistics (routes, wash, roof), not a different larva machine.