If you want one that rides on a small piece of rod, you would have to drill a hole in it(about 5/16 inch diameter is about right)
and several inches deep before machining the shape which is just a simple process using x and y axis to carve out the desired
shape. One can hold the handle to the rod(grooved) with a set screw or I have used a small plastic cylinder affixed to the end
of the rod that has a tight sliding fit into the handle. The drilling and machining is best done in one set up for concentricity.
I put a dab of grease in the hole before assembly.