My name is Kayla Lenz and I am studying Mechanical Engineering with a concentration in Biomedical Engineering. I chose this field of study because me favorite subject has always been math and I love being able to utilize creative problem solving. I am most excited to learn about the biomedical realm of engineering, including prosthetic development and at home health assesment devices.

Three most significant engineering inventions from the last 150 years?

I believe that refridgeration, automobiles, and cell phones are the three most significant engineering feats of the past 150 years. These products completely changed our way of life and gave us more flexibility with important tasks.

Design Analysis of a Dumbbell

In analyzing the design of a simple dumbbell, there are a handful of features that stand out as vital to the overall functionality of the weight. First, the two ends were likely designed as hexagonal prisms to ensure heavier dumbbells could be rolled on the ground if need be but the dumbbell would not roll away just by setting it on the ground, like between sets for example. Chamfered edges on the hexagonal prisms give the dumbbell a more appealing look. The diameter of the handle also had to be carefully chosen to provide optimal grip for the largest range of hand sizes possible. My analysis considers a fixed dumbbell, where the handle does not move, but some newer models feature an adjustable handle to provide ease of motion in exercises that require greater wrist flexion.

Dumbbells are typically made from iron and the end hexagonal prisms may be coated in rubber. Other materials such as plastic can be used to make dumbbells, making them cheaper and resistant to rust damage. Other solutions to the same problem that dumbbells solve (providing a functional weight for resistance training) include various models of kettlebells, fixed barbells, wrist weights, etc. Dumbbells are manufactured all across the world, and the process is described by Google Patents as selecting the raw iron and rubber materials, melting and casting the iron onto a model, cooling, polishing, and pouring melted rubber onto the outer shell. There is no patent for the standard dumbbell because it is thought to have originated from the Ancient Greeks. However there are many patents for the new adjustable models that have gained popularity in the fitness industry.