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Figure 1: Completed Prototype with Separated Wheels |
Figure 2: Completed Prototype with Joined Wheels |
Abdominal Roller
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Figure 1: Completed Prototype with Separated Wheels |
Figure 2: Completed Prototype with Joined Wheels |
Murshed Khadija
Summary:
I designed and built an abdominal roller because I wanted a cheap way to improve my stomach muscle appearance. I saw an advertisement on TV that was trying to sell an expensive gear driven abdominal roller. I decided to make something that was simpler and a lot less expensive.
To begin the design process customer and engineering requirements were defined. Some of the major requirements are small size and being portable. It had to have a small weight yet still be durable. It had to be comfortable to use, and it could not damage the floor. All components of the prototype had to be readily available and easily repaired.
Next in the design process came the need to determine the functions that the design must perform. Ideas were then brainstormed that could solve the individual functions. By combining different ways to solve different functions together, many potential design concepts were obtained. A decision matrix was then used to compare the concepts and to determine which concept was most suitable to pursue.
The actual prototype fabricated ended up being very different than the concept that the decision matrix suggested. It consisted of a ½ inch steel rod that was cut to a length of 24 inches. Two six inch lawnmower wheels that contained bearings were placed on the steel rod. E-rings were used to keep the wheels in place along the shaft. While the E-rings successfully held the wheels in place they had the ability to easily slide along the bar with minimal user effort so as to adjust the wheel placement along the rod. Four inch long bike grips were placed at either end of the rod to ensure the users comfort during use. The grips had an inner diameter of ¾ inches. Rubber hosing that had an inner diameter of a ½ inch, and an outer diameter of ¾ inches was cut to four inch lengths and placed in the grips, before the grips were placed on the end of the rod. To use the prototype one simply kneels on the floor and holding onto the grips, rolls forward and then rolls back into a kneeling position, using his/her abdominal muscles in the process. Figures 1 and 2 are photographs of the completed prototype.
