mecanum vs. omni

[Alex.Norton]

The difference between holonomic and kiwi is the number of wheels. A kiwi drive uses three wheels that are set up 120 degrees apart. A holonomic drive uses four wheels set 90 degrees apart. A kiwi drive is easier because of control and the physics of a holonomic but a kiwi inherently unstable because it is a tripod (how many three wheel cars do you see? They tend to be too tippy).There was another team that used a kiwi drive the first year that we used a holonomic but they where very tippy and didn't drive very well.

The reason that side forces aren't a problem with omni is that in an ideal omni wheel you can't have side force since there are rollers in that direction. People use them in tank drives to turn the robot easier because they don't create any lateral force in almost every situation. They only case that creates side force on the wheel is when the side of the wheel contacts something without contacting the roller. I could use 1/16th in acrylic to captivate my wheel because it didn't create side force. That is what I like about them, I only needed one strong piece for mounting my wheels (hub).