Assignment #4 - Modules Phase

MEGR 2156 Portfolio

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Problem Statement:

I regularly use my bicycle for exercise, transportation and leisure. While driving may be more comfortable and in some instances faster, cycling is far less expensive and far kinder to the environment. On the flip side, cycling is not always permissible regarding a weather and safety standpoint, and also may not always the most convenient means of transportation. As storage, comfort, and capability/ease of use through unsuitable situations and terrain are characteristics that may be improved upon, I am developing improvements and technologies that will make cycling more user friendly and attainable on a regular basis.

I have chosen to focus on a strategy that solves the difficulty I find when pedaling from a stop. Using caged-pedals to make for more efficient pedaling is common among road cyclists. Unfortunately caged pedals are sometimes difficult to use as the cage sits forward of the pedal, upsetting the balance and resulting in the pedal resting perpendicular to the road as opposed to a typical pedal that rests horizontally to the road. Such an imbalance creates difficulty of sliding your feet back into the cage, creating difficulty starting and stopping the bicycle, which can lead to nerve-wracking and sometimes even dangerous situations. To address this issue, creating a design to act as a counter-balance to offset the weight of the cage would create a safer, easier and more enjoyable cycling experience while maintaining the benefits of using caged pedals.

Build dimensions must be logical and consider performance and simplicity:

 The thickness/depth of the design to consider the ground clearance of the bottom of the pedal to the road, allowing adequate space so the design will not catch or make contact with what is below the pedal. The design must also be developed in mind to counteract the weight offset of the cage to create a resting angle of the pedal no more than 45 degrees above or below the horizontal axis to the road. The design dimensions will also consider simplicity and using minimal material to attach/ integrate the pedal of a bicycle with minimal fasteners and effort to ensure ease of installation and maintenance. Dimensions must also consider an appropriate size and shape that lies within the size of the pedal as not to make contact with the frame of the bicycle or any other components. Dimensions of the design must not extend outwards more than 2" from the flat-face of the pedal.

  Assumptions:

For this design, I may assume any material and manufacturing process may be used this early in my design process. The design will suit all of the parameters mentioned in the problem statement and address the needs of cyclists ranging from commuters to average/recreational and to active and competitive cyclists. The design will fit a set of pedals with specific construction/hardware. The design is also assumed to act as a counter-balance for a specific cage design and weight.



Updated Gantt Chart



In my Gantt chart I made some changes. In Assignment 5, I shortened the time required for determining a problem statement and extended the required time for determining necessary concepts and analyzing potential models. In Assignment 6, I shortened the time necessary to finalize the bill of materials and extended the time required to redesign and modify, and the time required to check my problem statement.

Updated FRDPRC Table




Decision Matrix

The Decision Matrix operates within six criteria: cost, weight, simplicity, stability, and space efficiency. Each category was evaluated and assigned a value between 1-5. 1 being associated with the lowest rating and 5 being associated with the highest rating given for each concept when assessed against their respective evaluation metrics. Thereafter, each rating is multiplied by the weight of the metric in the design, which are summed to equal the sum total rating. Stability and space efficiency being rated at 25% are the highest weighted considerations as it is important for the design to not only be able to withstand large forces and quick changes in direction while remaining stable and not falling apart, but also must stay compact and space efficient to avoid collisions with the pavement, the bike itself, and the rider. Cost was considered to be the second most important metric at 20% because low part and production costs are important to keep the price of a product low enough to profit on. Finally, weight and simplicity were rated both at 15% as the robust design of the part will likely have to do away with lightweight materials and simple construction, so they were both weighted equally to complete the table.

Relating back to the FRDPARCC tables of earlier assignments, strategy #1: the laterally adjustable pedal counterbalance was chosen as a result of good ratings in weight, simplicity and cost. The functional requirements of strategy #1 were: a mount to an underside pedal, the ability to produce a suitable counterbalance, and to avoid conflict with the asphalt. The concepts above were created with these functional requirements in mind, as they all serve the purpose as making a counterbalance adjustable. Also, the functional requirement of avoiding collision with the pavement carried to the design of the concepts in the form of space efficiency as an evaluation metric in the matrix above.




Multiple Solutions and Calculations


Module 1: Shaft Locking Pins




Module 2: Shaft & Set Screw





Module 3: Ball Quick Lock on Shaft






You can find and download the part files and assemblies here!

Click here to be directed to a shared google drive folder



Time Activities and Management Table

New Lessons learned:

As I have updated my Gantt chart and made a decision matrix to decide on a concept, I have learned as tedious and sometimes monotonous as they seem, following through the design process has made my progress much easier and I feel far more confident in my project and how I am progressing. I have also noticed the streamlined flow of the design taking shape, and I am beginning to appreciate the use of a Gantt chart and my decision matrices as much of my decision making in my design and progress in the modules and concepts of my design have been made much easier as a result.



Comments to Advisees:

Benjamin Ayala:

  • Great formatting and organization. 
  • Assumptions and problem statement were definitely improved.
  • Could use a little more color.
  • Could expand a little more on decision matrix explanation.

Mark Mcnerney:

  • Websites is very impressive, set up very well
  • All images and text was set up very very well.
  •  Was unable to access your assignment 4, was directed to assignment 3.


Undergraduate Mechanical Engineering: University of North Carolina at Charlotte