Oke , it’s not a beauty but it works very well.

So, let’s start.

Place a square piece of material in a 4 chuck.

Drill a hole in the middle.
And make it, in my case, 20 mm.

and make a chamber for a ball-bearing

Make a flat cylinder. The cam in the middle is for the ball-bearing. The thickness of the edge is the same thickness of what left on the plate.

Place the cylinder in the 3 chuck of a milling machine.

Make a slot in it.

place it in a bench-clamp and make sure that the slot is horizontal. Make with a flat cutter 3 holes in it. After this, drill 3 M8 screw holes till the slot.

Drills a hole for a long bolt. Do it not at the same side as the 3 holes.

Make a L shape of steel with the thickness of the slot in the cylinder.

Put all 3 parts together and place it on the lathe and mark the height of the L-shape.

Make with a milling machine the height .

drill 2 holes for the cutter.

Place the L-shape in a clamp and rotate the clamp for 30 degrees

make a rhomb shape.

clamp the pieces together with a countersink bolt.

Now you are ready to use