[EricH]

Originally Posted by rachal

4. Heavily dependent on the game and your machining/designing skill, and in most cases no. For example, we were able to align ourselves with ramps without wasting too much time maneuvering behind the home zone line, but we got pushed around too much out in the middle of the field. So even though we could easily get in front of another bot to block, if their arm was long enough to score over us they could just shove us into the rack. Definitely not worth it for the 2007 game. However, building a holonomic is a really fun experience. Everyone should try it once, even if not for the actual competition bot

We tried it in 2005, and if you looked closely, the robot had space for another set of trannies. We weren't sure until Week 5 or 6 whether or not we were going to use mecanums or 6-wheel, so we designed for both. We ended up going with the 6-wheel, for reasons you found out. (I think we were one of the teams that went over you this year.) Testing revealed that a simple 4-wheeled robot could (without turning) easily block a mecanum from going through a small target area.

Originally Posted by rachal

One of the downsides of mecanum is that if a wheel stops working/loses contact with the ground, the exerted forces no longer balance out, but you can still drive with two. So at some point, our programmer added code so that if a wheel went offline, its mirrored wheel would shut down.

Another downside happens when you have a decent weight held away from the robot. You effectively lose two wheels, and may start turning unintentionally while going sideways. Not good. It wouldn't have had as much effect this year, as a tetra is significatly heavier than a tube, but it is something to consider.