[Chris Fultz]

A few months ago, Cyber Blue began working on designing a crab drive system. We have always been impressed with the teams that do crab / swerve drive and do it well and have talked about creating a design for several years, but until this summer, we had not done any serious work on a design. We knew that to be successful, we would need to have a summer and fall development project before we could even consider putting a crab drive onto a competition robot.

We were evaluating our options and had studied several successful designs – looking closely at the Team 111’s (WildStang) drive and two of Team 118’s (Robonauts) designs. We intended to learn from these and create our drive. ("we stand on the shoulders of giants", as the saying goes)

A few weeks into our project, Anthony Lapp (Team 221 LLC) posted information about his Wild Swerve drive. We talked to Anthony and reviewed the information on his drive system.

Then we met and talked about our options as a team. In effect, we worked through a process which is common in product development companies, called “Make / Buy”. We evaluated the “pros” and “cons” of each of our options (design and make vs. buy and integrate). After continued discussions with Anthony, we agreed on a purchase of 4 “pre-production prototype” Wild Swerve drives. Through this summer and fall we will be designing a chassis system around these drives and working on programming and control.

During this process, we will provide regular feedback to Anthony so that any issues or concerns on the drives can be addressed before he begins full-scale production.

We are also going to document and publish a white paper on our work, starting with our initial review of designs this spring and following though final integration of the drives and the controls and programming to create a total system. We think this will be a significant benefit to other teams.

We will do mini-updates along the way, sharing what we are learning.

We also realize there is ongoing debate on the merits of “make / buy”, especially on a system such as this. As is often the case in FIRST, this debate is echoed in product development companies as well. Each new project involves decisions on what components to buy and use “off the shelf”, what components to buy and customize, and what components to design from a clean sheet of paper. Each option has merits based on cost, schedule, capability, intellectual property protection and corporate knowledge. There is never an absolute right or wrong answer. Each organization makes their own decisions based on their final situation, vision and strategy.

For now, we have selected this path and will share what we learn along the way.