A Braille printer forms dots in paper, which are read by blind people. The dots are produced by hammers, which basically consist of a spring loaded moving core that is excited by electromagnetic forces. The system is characterised by non-linear properties such as electromagnetic forcing and impacts. Problems with quality, high temperature and noise limit the operating speed of the printer. To investigate if printing quality problems are caused by the non-linear dynamics in the system, one existing design is modelled and used for evaluation. The simulations show that some mechanical parameters are critical in order to get satisfactory quality on the Braille text.