5. Results & Discussion

1. Introduction     2. Design Considerations     3. Kinematics     4. Prototyping & Building

This mechanism did not fulfill its purpose of driving a fan with a bike trainer for two primary reasons 

1) I was unable to drill straight holes through boards and PVC pipes, making motion wobbly and not smooth. Thus, I was never able to successfully drive the mechanism with the bike trainer itself, although I think it might work with better manufacturing techniques and less friction. The apparatus designed to fit into the bike trainer frequently fell out and the axle was not parallel with the spinning of the wheel, producing erratic movements. 

2) The parallelogram mechanism was not actually a parallelogram. While I measured link lengths carefully, the movement of the lawnmower wheel was out of plane due to wobbly rotation. Moreover, the shaft rotated by Link 4 was not exactly perpendicular to the planar mechanism and produced even more wobbly movement. Finally, the PVC links did not slide smoothly past eachother. Thus, the shaft rotation changed direction at toggle points, producing a fan motion that stopped and changed directions frequently. 

The following videos document the final results:

Despite the overall failure of the mechanism to achieve its desired result, I am satisfied with the outcome of the project because I successfully reassembled the Roomba.

1. Introduction     2. Design Considerations     3. Kinematics     4. Prototyping & Building