Concrete Volume Control Knob

thingiverse

I wanted to build a concrete volume control knob for my computer. I had found some had done so with paper molds and although they seemed to work well they I was looking to do something that was overly complex so I made my own. I also wanted to do something a bit different (again, think too complex for my own good) and have a free floating button in the center of the knob to mute the volume. I ran through several designs before I came across one that worked well. The mold takes the form of several pieces which allows for the center button, a curved top and an easier removal from the mold pieces. I smoothed out the mold interior surfaces with some primer filler and some light sanding. I used some light Vaseline as a release agent. Once dried (slowly) I coated with a few coats of poly to finish. Here's a note, when you fill the mold with concrete make sure you vibrate it enough to remove as many air bubbles as possible. Gently bang the mold on a hard, flat surface to help accomplish this.