4´x 8´router build

[lamicron]

Hi all, I ´ve alr¡eady build two CNC 4´8 plasma tables, now building same size router, the question is: i was going to use rack and pinion (20 pitch, 20 tooth due to the length, Is it better to use ball screws for this length , which diameter will be the best? If it is best rack ansd pinion wichich pitch.
I´ve seen a biesse router from italy (big one!!!) with gear rack module 2.5
Anyone have build something like this?
Thanks for help
Luis

[harryn]

Are you happy with the result of your plasma table - for accuracy, speed, durability, etc ? If so, then maybe the easiest way is to just improve on your current projects.

[contactirfu]

look at www.mechmate.com, they use all rack and pinion and have specified the exact sizes.