6.4 Implementations

Manufacturing

All the gears and linkages are made in-house. We chose to make the gears using FDM 3d printing. We chose this method over laser cutting to save time. For laser cutting, we must fit the gear directly onto the D-shaft of the motor. We have to account for the KERF of the laser and it will give us different thickness around the motor shaft. This will be hard to secure onto the shaft and we may need to use bonding agent to secure the gear onto the shaft. Since acrylic is a brittle material, too much torque applied to a thin sheet of material may introduce cracks. 

Instead, we used FDM 3d printing to manufacture the gears. This allowed use to include a set screw hole on the offset of the gear to account for shaft slippage.

The linkages and baseplate were laser cut, since it provided more accurate hole locations and more reliable press fit with the bearings. 

The motor housing and mount are also 3d printed. The housing hugged the motor, and we used 3 screws on one side to clamp down the motor to secure and for easy removal.

Assembly

Once everything is manufactured, we started putting the mounts and the vertical plates on the base plate. Then we inserted the shafts and bearings onto the 6mm rods. Using shaft collars, we were able to secure the gears and bearings into place. The battery fits perfectly inside the motor mount. After running the mechanism for the first time, we found that the rod is swinging to fast due to the battery. Using a breadboard and a 330 ohm resistor, we were able to use a simple voltage divider circuit in series to lower the voltage delivered to the motor to ensure that it does not run too fast to avoid the fishing rod’s motion to be unnatural.