6in WCD vs KOP

I worked on a 4in WCP single-speed drivetrain over in the offseason based on the request of the software team to add precision to their auto program. We have been using the KOP drive prior to this point. Because of the constraints of this year’s game, it is not really ideal to cross the borders with 4in wheels. We were thinking to change the front and back rails of the drivetrain from 1’‘x2’’ to 1’‘x1’’ or change to 6in wheels. However, my team is questioning the necessity of building a 6in wheels WCD, which doesn’t seem so different compared to the good old KOP drive. We are also worried that having 6in wheels would lose the precision and the whole point of building WCD. What do you think of the difference between KOP and 6in WCD, and should we go with 6in WCD?

The biggest difference I find personally is ease of maintenance with a WCD and that you can customize everything with a WCD.
That being said, have you built and used a WCD during a competition? If not I’d stick with KOP which is still plenty good

If you are trying to decide between a custom drive base or the kit at this point, and you have a kit available to build, you should build the kit.

There will be many, many WCD robots on the field this year with 6" wheels, however, so that’s not a reason to reject that style of drive base. WCD isn’t about precise driving so much as it is about increasing real estate inside the perimeter, and making wheels easy to fix or swap.


I am a little confused by this. Why do 6 inch wheels lose precision? Why do 6 inch wheels defeat the purpose of a WCD? Both a WCD and a KoP chassis work with 4" and 6" wheels, so I feel like in this scenario the frame choice and wheel choice are fairly independent.

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The software team asks for smaller wheels to maneuver more easily, so that’s our main goal during the offseason when we start doing a WCD with a low-gear ratio gearbox and smaller wheels. Now if we are changing the wheels to 6in, we are not sure of the difference between WCD that all good teams are advocating for and KOP. What does the WCD specifically accomplishes that KOP can’t? We seem to struggle learning the core idea of this decision.

Wheel size has relatively little effect on maneuverability, all things considered. The primary factors are center drop, robot mass, friction coefficients, and drivetrain power/ratios.

A west coast drive has three advantages over the kitbot: it’s lighter, has easier integration, and more easily serviced. Since you have control over the frame rails, you can add whatever mounting holes you want. Also, the wheels are cantilevered so that they can be swapped or replaced with ease.


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