mwp, check out the Thompson site, when using their shafting they recommend laying the shaft on a bed of epoxy that is on the support rail. You can use the same technique to linear rails...unless you have access to a huge mill where you can machine the surface where the rail will be mounted.
The next problem will be in adjusting the linear rails so that they are co-planar...fix one rail, and make the 2nd adjustable....I would level the 2nd rail using a rigid straight edge with a machinist level.....unless you have a perfectly straight - straight edge mark the spot where you place the level and where the straight edge meets the linear rail's trucks. |