Use of epoxy for levelling

[mitchejc]

Regards not using a bridge can I ask how you know there is no difference in height between one side and the other.? Ie both rails on same plane.?

Jazz, the way I see it the X rails don't have to be on the same horizontal plane as long as the two planes are parallel ie. if rail X1 is 2mm higher than X2 it must be 2mm higher everywhere along the length. There's probably other ways to do it but I epoxy casted a T shape reference surface on my base and used that to set up my Y and Z. The machine in the extreme example below will cut perfectly well as long as the y rails are parallel to the ref surface who's horizontal plane is parallel to the two x-planes. Mine, does not look like this as the x height difference was minimal:-) I used little skrew adjusters and then epoxy putty to shim my gantry bottom parallel to the ref surface and gantry front perpendicular to the ref surface and also used the ref surface to set up my Y rails and Z. Casting the ref surface does add a bit of extra work but once its there its very easy to set up Y and Z as opposed to some other methods I've seen.