I've been thinking about actually using this system to level the X beams (80mm steel box section) on my new machine, I will outline my current thoughts on the process and welcome your criticism.

I'm thinking the basic process would be:
1. Deposit a 30-40mm wide strip of machinable rail bed material on top of the beams where the rails will go.
2. Use the laser system to level a piece of milled aluminium plate with a window cut in it over where the rail will go. The plate could be clamped and brought into plane with the laser using 3 jack screws bearing on the steel beam.
3. Take a trim router and using the plate as a router guide mill the rail bed down to height. Move the plate along the beam, rinse and repeat, then repeat for the second X beam.

The trim router would be height locked throughout the whole procedure, potentially tape could be used on top of the router guide for a roughing cut, then removed for a finish cut. The laser would also have to remain in location.

For the rail bed I'm thinking of polyurethane metal filler laid to a depth of 1-2mm, hardens quickly and is fairly easy to machine.

I don't have a trim router, although I don't mind picking one up. Does anyone know what sort of Z-play units like the small Bosch or Makita have?

Thoughts on success of this process?