We've received the tapered aluminum section of our spar mandrel from a flagpole and lighting manufacturer. The mandrel is a straight length of tube around which we”ll wrap prepreg carbon fibre (carbon fiber tape pre-impregnated with epoxy resin). The carbon/mandrel combination is then cooked in a long custom-made oven to produce our rotor spars.

Much of yesterday and all of today were spent polishing the mandrel in order to ensure our carbon spars can be removed once they have cured. Take a look below for a quick time-lapse of (some of) the polishing process.