I'm looking at buying a small benchtop CNC milling machine to primarily do 3D carving of custom generative art, similar to this example. I would have no problem sticking mainly to softer materials like foams, plastics, and soft woods, but it would be fun once in a great while to do some hardwoods or even aluminum (rarely).

Trouble is, I live in apartment with neighbors above, below, and on one side of me, so I want to make sure I've done my homework on noise reduction before I make the purchase. In my experience, I never hear vacuums running in my neighbors' units, though the wheels running along the floor I do hear once in a while. So using that as a sort of benchmark, if I can get the machine running at about the volume of a household vacuum (or less, for my own benefit) I should be OK!

Originally I was looking at Inventables' Carvey (now discontinued) and Carbide3D's Nomad 883, but now I'm strongly considering the CNC Piranha FX, though I'm wary of its closed-source control module (a topic for another thread maybe). The vendor (Next Wave Automation) also sells this nice (albeit a bit overpriced, IMO) see-through enclosure that I'm very interested in for dust containment and slight noise reduction. I'd LOVE to use this enclosure, but I'm not sure that it would provide the level of sound dampening I need on its own (or would it?).

The obvious solution here is to build a custom wood enclosure with sound-dampening acoustic foam or DIY alternatives, and maybe even inner walls with an air-gap. However, I'd love to be able to look at and film the machine from multiple angles, so the idea of locking it away in a wooden box with tiny windows and LED lighting wouldn't be ideal.

Here are some ideas I have for reducing noise. Do you think the combination of some or all of these would be enough to let me get away with using the plexiglass enclosure I linked to? Do you have any other ideas for reducing noise, even in small ways?

  • Mechanically isolating the table from the floor using rubber mats to reduce vibrations transmitted to the apartment below.
  • Using a 500W, or even 300W, air-cooled spindle instead of a trim or palm router. Specifically I'm looking at this one.
  • Always using less aggressive milling strategies like small step down and low feed rates. Basically "optimizing" toolpaths for low-noise, not production speed.
  • Running the dust collection vacuum only intermittently. Building a wood enclosure with acoustic foam for this would be OK too, if needed.
  • Sticking primarily to soft materials and 3D carving, so the noisest operations (like first-pass stock clearance) would only last for the first few minutes or hours.