CAIBI project benchmark: Precious Plastic Shredder 3.3
Prompt version 1.0

Help me build Precious Plastic Shredder 3.3 using the existing creator project at https://community.preciousplastic.com/library/shr---33-. This is a CAIBI benchmark adaptation of the project build brief, not a claim about how the creator used AI.

Project context:
- An open-source workshop machine that reduces sorted plastic waste into flakes for later recycling processes, with downloadable fabrication files and a documented safety-focused 3.3 revision.
- Build context: Shredder 3.3 laser-cut/machined metal parts and fasteners from the official BOM; Shaft, knives/spacers and bearing assemblies from the source package; Fabricated steel frame and hopper/guarding components; Geared electric motor and drive/coupling components specified for the chosen configuration; Contactor, overload protection, safety switching, emergency-stop/control hardware and enclosure components; Wiring, terminals, protective earthing and other electrical hardware specified by the source/manual and local requirements.
- Where AI helps: Explain the supplied CAD, drawings, BOM and assembly sequence, Help organise fabrication packages for outsourced laser cutting or machining, Cross-check dimensions and documented tolerances against the source files, Help create inspection and commissioning checklists from the official manual, Troubleshoot non-safety-critical assembly observations against the documentation.
- Physical work: Decide whether you have the fabrication and electrical competence to build this machine at all, Source or subcontract the metal cutting, turning and welding, Select and install the correct motor, contactor, overload protection and controls, Fabricate and assemble the frame, shredder box, bearings, shaft and drive, Install and verify guards, safety switching and emergency-stop provisions, Inspect alignment, fasteners, electrical protection and rotation before commissioning, Read and follow the current operating manual and local machinery/electrical requirements, Operate only with suitable sorted plastics and keep hands/tools away from the cutting chamber.
- Main limitation: The shredder combines fabricated steel parts, bearings, a high-torque drive, exposed-workshop fabrication processes and motor/control electrics. The current 3.3 revision was specifically changed around safety, but following an open design does not itself certify a home-built machine. Guarding, interlocks, electrical protection, emergency stopping, alignment and safe operating procedures require competent human judgement and local compliance checks.

Read the source first. Use its published design, files, dimensions and parts as the baseline; do not redesign it unless a missing detail requires a clearly labelled proposal. If you cannot access a source or verify a revision, say so.

Provide one practical build package:
1. Design and files: explain the source design, link the original editable files, and identify missing files or modifications.
2. Parts and fabrication: give quantities, exact variants and compatibility, plus a cutting or printing list where applicable. Preserve source dimensions; flag anything unconfirmed.
3. UK and US purchasing: direct product links, checked dates, stock, pack sizes, taxes, delivery and regional costs. Mark unverifiable details as unknown; do not invent links, prices or availability.
4. Assembly: an ordered guide covering fabrication, fitting, wiring or software as applicable, setup, checks and troubleshooting.
5. Cost and time: separate parts, fabrication, delivery, hands-on time and machine time, with assumptions and exclusions.
6. Function and ease: a test plan for the project's stated purpose, likely difficulties, required skills and any corrections or limitations.

Keep source facts, your proposals and items needing physical verification distinct. An estimate is not a measured build result. Do not claim to have built or tested hardware. Include failed attempts and omissions. If a section does not apply, say why.

Use the source as accessed during this run and record its revision or access date. The prompt is fixed; the linked source can change.