MEG 320

Spring 2001

Project 1

The figure below shows a concept for an elliptic exercise bike (click here to see animation of the motion). The height of the slide can be varied between 0.1 m and 0.6 m to change the difficulty of the exercise. The dimensions of the bike, as shown in the figure below, does not necessarily produce an acceptable performance.

Modify the design, while maintaining the concept, to ensure that motion can be completed within a comfortable range of motion fro the user. Assume that the upper body does not move. The following are suggested steps:

i. Find out the ranges of motion of each joint involved in the motion.

ii. Draw the corresponding mechanism.

iii. Identify the loops, joints, and the number of degrees of freedom.

iv. Should this mechanism be a quick return mechanism? Why? If so, design it for an acceptable time ratio.

v. Modify the design according to the criteria specified before. Check the mechanism at both extremes of the slide height.

vi. Use Working Model to show your final design. (Remember to plot the path of the foot to ascertain if it really an ellipse) (Click here to load the file)