I'm trying to decide whether I can get away with a 3" ball or if I will need the extra room that a 2 1/4" ball will give me on my control panel. The dimensions of the panel are 25" W x 7 1/2" D. Expanding the width of the panel is not an option for my design.
Golden Tee type game will be on this machine, but obviously wild power swings will be limited by space on my configuration. Mainly the trackball will be used for gentler controlled games like Centipede, Crystal Castles, Missile Command, etc...
Here is a scaled mock-up of the two options...

I'd be interested to hear from others that have trackballs on similar sized panels.