I drew a horizontal line from the outside top right to the center of the pull.
Made a circular array of copies. Rotation center at the left end of the line, Rotate Copies box checked, 41 copies, Total Angle 184.5. Node edit to be sure the start point is on the outside end of each of the lines.
1. The fluting toolpath causes the center of the bit to follow the vector. So, if you use a 1/4" end mill, it will cut 1/8" beyond the end of the vectors. If you want the pull to have a radius of 1" and you are using a 1/4" end mill, the vectors should be 7/8" long. And the length of the pull will be 1 1/8, not an exact circle.
2. When you use the fluting toolpath to cut a curved surface like this, I've found that if the maximum distance between vectors is about 1/4 of the end mill diameter, the resulting surface is satisfactorily smooth. You can experiment with other vector spacing if you wish to reduce the cutting time.
3. The circular array leaves a space after the last vector. So to get a full array of vectors, the total angle has to be Angle desired + Angle/(no. of vectors - 1). In this case, it was 180 + (180/40)
4. The picture used 61 vectors, but 41 vectors should be satisfactory and take less time.
Good judgement comes from experience.
Experience comes from bad judgement.