DIY Laser levelling using webcam and laser level

[Kitwn]

Joe,
Whilst replying on your build thread an idea came to me. I'd be interested in comments on it's practicality:

Could your laser leveling camera and software, possibly using a taught wire as John is doing, be used to measure the height errors as a gantry machine moves along it's imperfect rails and edit the Z axis G-code to correct for them in much the same way as a probe is used to measure and correct flatness errors in PCB cutting?

In this way a machine of modest accuracy could be used to build parts for a better one. I'm thinking specifically of jobs like grinding the top of gantry profile as you have done for your build.

Initially I'm thinking of only flattening a linear cut as above but since your stated aim is making planar measurements is it reasonable to think of correcting over an area in order to turn plain old ally plate into something approaching tooling plate or even turn a piece of granite worktop into a reasonably accurate surface plate?

Kit