I usually eyeball my end mill to the front left corner of my stock, usually carefully rotating the mill by hand to make sure it’s centered over my intended origin. Then I realized I have one of these, which comes apart to reveal this other pointy thing. Turns out the pointy thing has a 1/8 inch shaft, so it can go into my Nomad’s collar and when it does, I can see EXACTLY where it’s pointed and thus were my spindle is located. Then I set my zeros. Anyway, thought somebody might find this helpful. 'Course, once those new touch plates from C3D come out, this may be less relevant.