Summary

65mm oversized USB volume knob. Uses all Adafruit gear: rotary encoder, trinket & gemma (temp till rev 2), and 16 pixel NeoPixel ring.

Instructions

Print all three files: knob,base and cover.
If using a NeoPixel ring for illumination, print the knob in a natural/clear filament.
For the knob I suggest concentric infill and concentric top and bottom fill patterns.
Obtain parts from Adafriut:
Trinket: (trinket, trinket pro, gemma, flora etc)
https://www.adafruit.com/products/1501
Rotary Encoder:
https://www.adafruit.com/product/377
Optional:
NeoPixel Ring:
https://www.adafruit.com/products/1463
Gemma/Trinket
To program and wire I used Adafruit's tutorial:
https://learn.adafruit.com/trinket-usb-volume-knob
Use a little hot glue to secure the neopixel ring in the recess, trinket to the base cover and the cover to the base.

Large computer volume control knob