DIY Laser levelling using webcam and laser level

[devmonkey]

Hi guys,

Fixed some UI issues so it should work on a 1024x768 laptop screen (just for you Kit). I've also added linear regression to the measurements taken. This is because the best way to use this imho is not to try to align to the reference plane (the laser) rather to calculate the error to the reference plane and then to shim or scrape such that these errors lie in a straight line. Please let me know if this makes sense to you. It is kind of a fudge and only works because given our vertical resolution is only +/-1mm and we are using it over a range of over 1000mm (or however long your x rail is) giving a worst case divergence angle of ~0.1degrees, i.e. the laser and the linear regression are very nearly paralllel. This implies a worst case vertical error of the residual caused by the divergence of the regression line from the laser is a rather small 1 nanometer, 1000x smaller than our sensor resolution.

The app now plots both the absolute and residual errors and tells you how much to shim or scrape at each point. So this is everything we need to level a rail, and when operated with a vertical laser line everything we need to straighten a rail. When I get around to it I will add two further measurement types, one for getting two rails planar, the other for tramming the spindle.

https://github.com/betzuka/laserleve...r.zip?raw=true


Cheers, Joe