Designing a Free Degrees Abdominal Wheel Roller Fitness Training Device

Project Info


Our client requested designing a customized Free Degrees Abdominal Wheel Roller Fitness Training device. The main feature of this device that made it distinguished from the existing devices was that it was to be used in pairs with each hand having its own roller device.


The main requirements for the design were the following:

  1. Free angle movement
  2. Comfortable
  3. Produce the maximum work-out result
  4. A locking mechanism with one finger without releasing the device
  5. Heavy duty
  6. Simple
  7. Practical
  8. Cost-effective


The initial design was composed of three parts including top, middle core and the bottom part; however, since the device was to be produced by injection molding and for cost issues, the initial design was later changed to two parts, i.e., the top and bottom section as a whole and the middle core with wheels. To make the body of the device heavy duty, Plexiglas which is a hard plastic was used. Also, to meet the client’s changing requirements, first a PoC prototyped was made and after some requested modifications, a fully functional prototype was built.

The other features of the final product included the followings:

  • Since the device was to be used both as a roller as well as a push-up stand, a switchable locking and rolling mechanism was implemented. The final design included four legs for locking the device with 6 wheels for the ease of movement in all directions without losing its strength
  • In the design, no metal parts were used in the wheels except for the central pin which was not heavy.
  • With regards to the choice of 6 wheels, calculations were made to make sure that the wheels will not increase the stress on wooden surfaces.
  • Also for the ease of using, a round-handle with finger grooves was implemented.

The product took about two months to be designed, prototyped and shipped to the client. The final functional prototype met all the requirements and was satisfying for the client.

I. Bedford
January 28, 2019
Mechanical Engineering