6.1 Project Proposal

Introduction: 

The motivation for our project originated from a desire to assist people with limited mobility in the cast and reel motion of using a fishing pole. With this in mind, our team did some research and was able to find an automatic fishing rod that was made for people who could not reel or cast the rod.

Fig 1. Inspiration - (https://youtu.be/tgfRZYOleIs?si=Lt5Dp_RUUNt5rQ-O)

Our idea is an automated fishing rod that could reel itself all while having smooth motion throughout the casting. However, we want to recreate this on a smaller scale. Our automated mechanism would have a fishing rod that can exert some force to throw the finishing line and after some time, reel in the fishing line. If time permits, we intend to have a bucket of “live” fish that would be paired with the rod which would create the scene of a fishing rod aiming at the bucket and retrieving fish. 

Problem Statement: 

For this project, we plan to use a 5-bar mechanism to swing the rod forward in a manner that will replicate the full casting motion. The hook must be propelled with enough velocity and with the correct path of motion to be thrown at a distance similar to that of a person traditionally casting a rod. Additionally, we will aim to incorporate intermittent motion to mimic the waiting period between subsequent casts of the rod.

Mechanism: 

We plan to use a 5-bar linkage to recreate the motion of the tip of a fishing pole during a full cast. The arc of motion must account for the motion of the swing as well as the bending of the pole. The slotted link will be driven by the linkage connected to the input motor to achieve a rapid-release motion, which will then be translated to a ternary link whose path will trace the motion of the fishing rod tip (see figures [2] and [3] ). We plan to include a geneva mechanism to achieve the desired intermittent motion, which, if successful, will produce enough time between swings to properly imitate the waiting period for a fish to bite.

Fig 2. Preparing the Cast

Fig 3. Resting Position

Proposed Scope: 

Our plan throughout the semester involves research and conceptual design development (we are currently here), preliminary prototyping, designing on CAD, preliminary fabrication, developing code, integration and testing, and aesthetics. 

A rough timeline detailing our intended process throughout the project is as follows:

Week 1-2: Outlining our goals and researching mechanisms fit for the design. Prototyping with objects that are accessible such as cardboard, paper, rubber bands, and string. 

Week 3-5: Designing a model on CAD that is inspired by our prototypes. During this time we will be 3D printing and fabricating some parts as well as modifying the design for our needs. We need ample time for manufacturing and modifying the design in case of failure.

Week 5-6: Developing a code that can automate our fishing rod and integrate all our parts together. This step will involve testing of the code and making sure all parts are working properly.

Final week: This week will involve final touches and working on aesthetics to make the final product more presentable.

Prior to fabrication, we will analyze the motor output to determine if they are powerful enough to throw the rod forward with the required force. Additionally, we will research material selection to determine which materials will meet our strength criteria. Most importantly, we need an analysis of the forces and conditions needed when we want the rod to stop being thrown and begin the retrieval process. Some additional steps we could take to fully address our problem include researching how much force it takes a human to be able to throw a rod, how far we want the line to be cast, and where we can use gears to facilitate out motions should the force generated from the motors prove insufficient. 

Our group will aim to completely solve our fishing rod design problem and, time permitting, we seek to challenge ourselves by including an additional component to add an artistic element to our scene: a fish rotating in a “bucket”. This motion will roughly resemble a carousel and serves as a purely aesthetic addition that will allow us to incorporate a different complex motion.

Preliminary design work:

Using MotionGen, we came up with a 5-bar linkage mechanism with a slotted joint as shown above. It has 1 degree of freedom. The kinematic diagram is shown above as well, showing the paths of the joints of the mechanism. The input link is allowed to make one full revolution so it is considered a Grashof Type I mechanism.