Why is the Roomba so expensive? Why are the knock-offs so cheap?

What happens when all the engineers from Delve's three offices gather in Madison? We buy stuff and tear it apart to understand how it is made. Our product of choice? The robotic vacuum. We picked two competitors – the Roomba from iRobot that created the category and the Pure Clean knockoff.

Time-lapse of our little experiment.

We had two goals for the activity:

  • Identify the top five ways that Pure Clean achieved their low price point ($93 retail for the Pure Clean vs. $248 retail for the Roomba 675)
  • Get inspired by clever design solutions in each robot.

    Within about 20 mins the difference between the two products was pretty clear. The Roomba is larger, more powerful, smarter and more fully functioned than the Pure Clean. Winning on all of these fronts costs money and the top five contributors to Roomba's cost were:

    1. The part count is more than twice that of the Pure Clean and it is physically much larger. This part count drives expense both in cost of goods (COG) and assembly time.
    2. The battery is twice as powerful, leading to better suction and longer battery life. The battery is also much more advanced, with a sophisticated power board and presumably better- quality cells.
    3. The “motherboard” is twice as large with a better processor and much more input/output (I/O), suggesting superior firmware and significantly more effort was involved in hardware and software engineering.
    4. It incorporates a larger number of sensors (proximity, impact, etc.) with a significant amount of wiring and assembly.
    5. The packaging is sophisticated and the overall user experience is much better. For instance, the Roomba comes with an app and a dock while the Pure Clean requires you to plug the robot into an outlet with a power adapter and has no app.
      12 Article Jesse Roomba B @2X

      After we agreed on the cost drivers, each engineer found a part that intrigued them and shared the part with the team so we could each see the “magic” that was built into the projects. We all get into design ruts and start designing products the same way every time. Seeing clever manufacturing and design solutions helps broaden our engineering toolbox. Here are a few of those “magic parts” and what we think is cool about them. Probably because the Roomba does so much more than the PureClean, only one of these parts comes from the PureClean.


      The simple axle in a plastic hole (below) runs incredibly smoothly. It is a lesson in surface finish, material selection and dimensional tolerancing to reduce part count but not sacrifice quality.


      The filter door below was molded at a 45-degree angle to allow a simple open-shut mold and then bent on a living hinge to create an overlapping assembly. Clever use of a single plastic part.


      The rotating brush bristles below are assembled and stitched into place (likely the bristles are bent in half so the middle is captured by the stitch). The bristles would likely be hard to “shut off/on” with an insert mold. It is also surprising that there is a left and right brush to create the directionality of the bristles likely the result of many iterations of prototypes to get good dirt collection performance.

      12 Article Jesse Roomba K @2X 1
      12 Article Jesse Roomba L @2X

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