Hobby CAD, CNC machining, and resin casting (2015)

Original Article ↗ Hacker News Discussion ↗

Longevity of the Guide & Updated Resources

  • Many readers still find the 2015 guide highly relevant, but note some links/products are defunct.
  • Successor resources and wikis are mentioned (Shapeoko-related docs, Reddit CNC wikis, newer A‑to‑Z guides).
  • Several people report following the guide successfully, especially for wax machining and resin molds.

CNC vs 3D Printing & Resin Casting

  • Multiple comments emphasize that resin casting from CNC‑machined molds yields much higher precision and better mechanical properties than FDM printing.
  • FDM can be tuned but struggles with surface finish and reliable ±0.1 mm accuracy; CNC in hobby setups can achieve ~±0.02 mm.
  • Modern SLA/MSLA printers narrow the gap, but surface quality for casting and long runtimes remain issues.
  • CNC is described as far less forgiving than 3D printing: more ways to crash tools, mis-zero, or mis-fixture.

Tools, Materials, and Capabilities

  • Hobbyists describe machining aluminum reliably on small machines; steel and titanium are seen as much harder and often impractical at this scale.
  • Detailed discussion of how to create hex holes (rotary broaching, milling approximations, punches, or manual filing).
  • Knife blades and small tools are feasible: usually machine soft steel, then heat-treat. High-end steels and complex lock geometries push toward more serious setups.

Hobby CNC Machines & Designs

  • A DIY fully enclosed sub‑$1,000 mini CNC optimized for aluminum is described, positioned as an alternative to 3018‑class machines and larger desktop mills.
  • Debate over cheap 3018/3030 routers: some claim they can cut aluminum with upgrades, others report persistent chatter and poor results.
  • Commercial options like the Milo and Carvera (and Carvera Air) are praised for capability; concerns center on footprint, rigidity, spindle power, and especially software.

Workholding, Process Complexity, and Cost

  • Workholding is highlighted as a major, often under-taught challenge; clamps, vises, soft jaws, jigs, and fixtures dominate real setups.
  • Tape-and-superglue workholding is mentioned as a convenient alternative for some jobs.
  • Consumables (end mills, vises, collets, stock) and tool breakage make CNC notably more expensive than hobby 3D printing.
  • Some suggest outsourcing to services (waterjet, laser, machining bureaus) when local shops won’t take small jobs.