1. Introduction 3. Kinematics 4. Prototyping & Building 5. Results & Discussion
MATERIALS
To design this mechanism, I embraced the concept of bricolage, or designing and building with whatever materials are available. Before considering any design ideas, I searched my house for materials that could be useful. I knew that I would need gears to produce an appropriate fan speed. I found two sets of gears in a manual lawnmower (Fig. 1), various gears in our Roomba (Fig. 2), and gears from an extra bike cassette. I also found PVC pipes, dowels, and scrap wood to build a linkage mechanism and supporting structure (Fig. 3). I knew I would need joints for gears and linkages to spin smoothly. I decided I could use nuts and bolts as revolute joints, although the movement would be less smooth than using shafts and bearings (Fig. 4). I did not have properly-sized shafts for gears. To solve this problem, I wrapped dowels in duct tape to fit them into lawnmower gears and used small nails for the Roomba gears.
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Figure 4: I experimented with making joints out of assorted nuts and bolts.
1. Introduction 3. Kinematics 4. Prototyping & Building 5. Results & Discussion