An exciting project with many challenges: The swing-up inner flip provides ideal conditions for welding as well as grinding. In addition, a construction site helmet was integrated and a swivel mechanism for the complete welding mask was developed. With so many moving parts, comfortable operation is crucial, for which the acceleration sensor of the smartphone was also used at times to analyse the impact of the inner flip on the welding mask (third picture). The construction site helmets were simulated and then tested on the test rig in our office according to the common standards.