yeah its the crystal trackball. the size of the tube was 2 inches. any larger is too much. i got a lot of reveal from the setup i used. i was pleasantly suprised. i did something a bit different than the instructions on this site.
*i will include pictures of some of this when i get home - it may be a little confusing until then*
first i used a 2-1/4" hole cutter in my drill to make the hole. then i took the pcb for the trackball, flipped it over and laid it on a piece of paper. i then traced around all of the parts that were raised (the wheels, rollers, etc...) and the outside of the board. you dont have to be perfect, you will have to make changes as you cut anyway.
next i cut holes in the paper along the lines i traced. then i laid it on the bottom of my cp and traced along the cutouts so i knew where to cut.
****MAKE SURE you line this up perfectly centered with the hole for the ball. otherwise you will have to enlarge all of the cuts so you can move the board and center it and you might not have anyplace left to screw into****
what i did next was, using a dremel tool with the drill saw and depth guide, made cuts about 5/8" deep in the underside of the panel.
my cp is 3/4" thick so your depth may need adjustment. i did this where anything was raised up on the pcb board and after, the board could sit a LOT closer to the cp. this meant that the ball could come through more on the other side.
then i just drilled some holes on one side and used a bracket on the other to hold the pcb up to the bottom of the cp. i also used some washers as spacers to make it sit a tiny bit lower so the wheels wouldnt rub the wood at all.
all i have to do now is glue the plastic ring on and it holds the ball in perfectly. im not doin that till i put somethin on top of the panel of course.