My Othermill is great for making PCBs, metal and plastic parts at home, but with a 26k RPM spindle, it can get quite loud. In order to improve the quality of life around here while it's doing its thing, especially on long aluminum jobs, I built a sound-dampening enclosure for it. The cabinet was cut out of a single 4' x 8' sheet of 3/4" thick plywood at UC Berkeley.

The panels I'm using for sound dampening are from McMaster-Carr, PN 5692T15. I 3D Printed orange nuts to hold them in place without having to glue them. In order to hold the door shut, I cut and bent two simple aluminum brackets, which hold a stretchy band between them. I used a tablesaw to cut 1/4" polycarbonate for the window, which is glued in place with hot glue.

Milling in progress on a 4' x 8' Shopbot Router.

Gluing it all up.

One of the panels with sound-dampening foam installed. The orange parts are 3D Printed with an M4 threaded insert installed for fastening to the wood.

Closeup of the simple door lock. The handle on the door had two small holes drilled into it for retaining the stretchy band with a cable tie.

Milling in progress.