Quote:
Originally Posted by jester_assault
As a part of team 357, I have been working with my team on different variations of Mecanum wheels for the past three seasons. One misconception we have found is that mecanum wheels cannot push or will be pushed very easily. However, we have found that mecanum wheels are good for what they are designed for. For example in 2005 we wanted a fast, highly maneuverable robot. We decided to use mecanum wheel with a fast drive train. Our design worked very well for us ad we were very happy with the results. In 2006, we modified our design to accompany a ten inch wheel, up-sized from our six inch wheel in 2005. By enlarging the wheel we got a much larger contact patch with the ground. As a result we found that we could push many robots, in all directions. In one competition we were able to push one robot, then another at the same time, preventing both from scoring in the upper goal. While mecanum wheels are not usually designed for pushing and are well known for their maneuverability, if they are designed right, and for that purpose they can be pushing force to be reckoned with, as well has having the known maneuverability of traditional mecanum wheels. If you want more more information our team is always glad help at www.team357.org or you can PM me. |
Contact patch has nothing to do with pushing force.
Coefficient of friction (CoF or Mu) is what gives you your pushing force and maintaining contact with the surface allows you to sustain that pushing force in a shoving match.
More than likely your wheels were made of a different material (better CoF on carpet), you had a better suspension (able to maintain contact with the carpet) or just had more power (more motors or lower losses in the transmission). Because of the accuracy needed to shoot into the upper goal, in 2006, just a small ram (momentum only) was needed to ensure difficulty in shooting.
Mechanums, by nature, do not have the pushing power because the bearings allow for translation from an outside source (IE low CoF when being pushed).