Hello Micha

Sorry for being late on replying to your nice solution, yes it is true that point73 is outlier, how I couldnt notice it.

Thanks a lot for your effort I highly appreciate it.

Can I ask what Nx, Ny, Nz, α are refer to cause I know that Mx, My, & Mz is the centre of the cone.

Are there any formula for cone in 3D space or can I do my least square my solve. I need to understand the matrix how it was build in to least square solution.

Many thanks for you, I really appreciate your contribute and your answer...

Regards