Just one piece of advice with the Robo - use a scissors and manually cut off all the long hairs when you first get your hair system. Making the Robo do all this is ridiculous and is a waste of time and effort, and will probably make the gearbox break down faster.

Leave 3 inches and then start to cut with Robo. If you need a longer style, then leave it longer but give the Robo some help at the start.