Lathe angle compound slide for the mill - video

[Karl_H]

What am I missing. I did not see anything there that could not have been done just as easily by clamping a lathe tool in the mill vice. I often use the mill as a lathe and I see no benefit in this device. I need educating.

As I see it, he has coupled the movement on the X & Z axis to one dial. To do so by simply holding the lathe tool in a mill vise, you would have to turn 2 handles at the same time, at specific a ratio, to achieve the proper angle.