maximum tabel size ?
 

whats the longest table i can build can it be 20 feet long and how much more will this cost other than the steel

Let me ask what you have planned for your machine:

• Materials cut
• Size of materials

Here is a 20' long MechMate <-----link

The length of table is virtually unlimited since all the intelligent motors and electrics sit on the gantry - the table is very dumb.

Once you go over about 12ft long, start thinking of more legs bolted to a concrete floor.....or, increasing material cross-sections of the longitudnal frames.

The costs escalate for the steel, but also for the cables, cable carrier (e-chains are not essential), gear racks.

Handling a dust collection hose of that length could become a big problem. If you have a lot of ceiling height above, you could think of suspending a hose (plus the cables)......

David one of the things i would like to do is route stair stringers
which i can get 9 .25 inches x 20 feet

Let the internet be your friend.... search around and you'll find some stuff like this:

http://www.talkshopbot.com/forum/mes...tml?1201906860

http://www.talkshopbot.com/forum/mes...tml?1082996801

You could easily build a 10ft machine and cut the 20+ft stringers.