Hi

Thanks for your reply Jonathan. To add a second rail, i was going to set it up and level it following your excellent instructions, then use the level surface prepared for the first rail, to mark the second. I was thinking of adding the second rail 90deg relative to the first ( on the side ) for the reasons stated in JAZZCNC above.

In fact, if i get the first rail level, and use it to mark the second, it would be quite hard to make it to far out ( as long as am carfull ). The main reasons i require stiffnes to the gantry is so i can add a B/C head or plate if needed. Am also adding a turret/lathe to the bed.