ENGS 21: A Solution to Rolling Dumbbells

[et_pb_section admin_label=”section”] [et_pb_row admin_label=”row”] [et_pb_column type=”4_4″][et_pb_text admin_label=”Text”]

From Thayer’s course description: “The student is introduced to engineering through participation, as a member of a team, in a complete design project. The synthesis of many fields involving the laws of nature, mathematics, economics, management, and communication is required in the project. Engineering principles of analysis, experimentation, and design are applied to a real problem, from initial concept to final recommendations. The project results are evaluated in terms of technical and economic feasibility and social significance. Lectures are directed toward the problem, with experiments designed by students as the need develops.”

The Team

With Prof. Scott Snyder teaching us in our 23W term, a trusty group of 5 was formed—myself, Wendell, as the team treasurer and rapid prototyping lead, Erich Woo ’23 as our lead test engineer, Pam Pitakanonda ’22 as our need-finding and design lead, Dak Black ’24 as the X-Clip CAD lead, and Will Dinauer ’23 as the V-Clip CAD lead. Despite our specialties, we often traded ideas and gave each other suggestions in our respective portions of the project.

Ideation and Need-Finding

During the ideation phase of our project, Dak brought up a common annoyance he had while working out with dumbbells—circular dumbbells roll around very easily. From our research, we found that almost all commercial gyms purchase circular dumbbells, not hexagonal ones, leading to our problem statement:

Runaway dumbbells cause frustration and pose an injury risk to the user and bystanders, and people using circular dumbbells need a way to prevent them from rolling away unintentionally.

Team X, ENGS 21 Proposal Presentation (2023-01-19)

Initial Prototype Development

A variety of cardboard functional mockups of the initial ideas we had for the project are shown here:

^{From left to right, top to bottom: the V-Clip, X-Clip, HexSleeve, Flexagon, and BuckleStrap in their initial prototype states. I personally worked on the Flexagon, which did not perform well in benchmark testing.}

Based on testing against the specifications we came up with, we decided to move forward with the V-Clip and X-Clip into the next round of prototypes.

Prototype Iterations

We next began to rapidly iterate on the V-Clip and X-Clip, using the 3D Printers available to us to our advantage, with myself taking the lead on taking the CAD files that Will and Dak produced into the physical models themselves using Prusa Mk 3 printers.

We went through a series of iterations before settling on the design which we will move forward with using a final material selection of steel:

As for the X-Clip, we went through a similar process with Dak CADing it while I printed it, though with slower iteration turnarounds. Plus, due to user feedback, we decided not to continue pursuing the X-Clip due to the bulkiness and lack of durability when faced with drop testing.

Next Steps

We plan on conducting user tests again with our finalized metallic V-Clip prototype. We will also conduct drop testing to test the V-Clip’s durability, an important specification when we decided on metrics for our product.

There is also the possibility that we will contact local gyms for purchasing agreements, along with a patent filing for IP protection purposes.

You can read the final report of our project here as a google doc, or below as a PDF:

[/et_pb_text][/et_pb_column] [/et_pb_row] [/et_pb_section]