A typical jambtype tilting garage door opening mechanism is

A typical jamb-type tilting garage door opening mechanism is illustrated below: (Fitmaster Tilt-A-Dor^TM, http://www.world-business.net/australia/Tilt.htm accessed 10 April 2016) Point G is the centre of mass, and point H is the fixing point for the garage door opener. theta is the angle between AC and horizontal, co is the corresponding angular speed. In this assignment you are required to write a report concerning the planar mechanism in the figure above. In your report, you must: Describe the links and pairs and calculate the mobility. Draw a fully dimensioned drawing of the mechanism shown, making reasonable estimates of all dimensions necessary to define the location of all points A to G. Estimate the mass of the door. You may assume that other mechanism components are massless.

Solution

Assume dimensions of the garage door = 4 m * 5 m * 0.025 m

Density of typical wood = 400 kg/m^3

Mass of the Door = Density of wood * Area of door * Thickness of door

                           = 0.4 * 10^3 (kg/m^3) * (4 m * 5 m) * (0.025 m )

                           = 200 kg