While the BB Controller has 4 axes, it only has limited support for rotary motion. The ability to turn a specific number of degrees is not implemented. For rotary motion, you would have to configure it to think the angle traveled is actually a linear distance. For instance, for a metric program, you would configure the axis to move 360 degrees in one revolution. That way, when you tell it to move by 45 mm, it would turn by 45 degrees.
This would work until you tried to run a program that runs with imperial units. Then you would have to reconfigure the axis for 360 inches per revolution.
This can work pretty well if you just use your rotary axis to do rapid turns to a new position.
Another thing that is missing is the ability to maintain a constant feed rate as the distance from the center of rotation changes. In other words, the rotational speed needs to be slower as the distance from the center of rotation increases, otherwise the feed rate will increase and possibly mess up your cut.
Change the axis from Y to A. Change your “travel-per-rev” to 360. This will have to be the case for all rotaries for our controller as it is. Change the “step-angle” to whatever is mentioned for your rotary, mine was stated to be 0.3 degrees.