It always was difficult for me to make the holes parallel in the axle. I made a little jig to solve this problem.
From plywood I made a 100% right-angle “jig”. On this plywood I put two wheels The screw in the “middle” of the wheel has an offset from 2 mm. By turning the wheel I can clamp the axle. Below you can see how it worked out:
Below is the situation on the drill press:
-- My englisch is bad but how is your dutch?