Linear polymers of glycerol can prevent or delay ice nucleation in a variety of contexts. The light-output system comprises a plurality of individually controllable light-output devices arranged in an array of light-output devices with a light-output device pitch, and an optical system arranged between the array of light-output devices and the projection plane. Additionally, a rust-resistant attachment mechanism is used attach the drill bit assemblies to the auger head, which makes the drill bit assemblies easier to remove and replace.