Ok! So, almost one year after I'm going to resume the operation "homemade bridge". I'll actually start over. I didn't like the angle of the edge I pointed out and the sharp corner in the middle of the plate. This time I'll also use this aluminum profile. And I didn't saw until both sawing lines met. I stoped earlier and broke the piece of. I wanted to sand a bigger and smoother radius where the two diagonals meet.