Mr. Rupert, thanks for posting the link to a very interesting video. It is really good food for thoughts. 
It uses the same physical principle – the law of reflection – as my laser goniometer.
Laser goniometer is not my invention, it is used in Catra instruments and was also described by US steel expert prof. Verhoeven. His paper inspired me.
As mentioned by Mr. Grepper, the you tube design may require more precise geometrical setup to estimate the bevel angle correctly. But on the other hand it has some advantageous also. Definitively inspiring for me.
When the reflection takes place on a hollow or convex grind, than the reflected laser line is not a single line, but a bunch of lines. The width of this bunch is given by the curvature of the grind.
It uses the same physical principle – the law of reflection – as my laser goniometer.
Laser goniometer is not my invention, it is used in Catra instruments and was also described by US steel expert prof. Verhoeven. His paper inspired me.
As mentioned by Mr. Grepper, the you tube design may require more precise geometrical setup to estimate the bevel angle correctly. But on the other hand it has some advantageous also. Definitively inspiring for me.
When the reflection takes place on a hollow or convex grind, than the reflected laser line is not a single line, but a bunch of lines. The width of this bunch is given by the curvature of the grind.