The second picture is how the disc should sit when catching balls. The first picture is about how it should be when ejecting them.

This whole mechanism is nothing more than a flipper. Instead of a flipper bat you have that moon disc. You loosen the pawl nut to rotate and adjust that disc.

The absolute biggest issue with this whole mechanism is the return spring. It needs to be stiff enough to catch fast moving balls but weak enough to allow the plunger and pawl to rotate. A standard flipper return spring is too weak. You have to get a fairly sturdy extension spring and play around with shortening it to increase tension. May want to get a few in case you mess up.

What a cool mech

For this assembly, the manual shows a system 11 style flipper mech with a compression spring around the plunger (between the pawl and coil). I swapped mine out for the external WPC style return spring and used an extension spring that was a bit too weak to hold a fast moving ball. I kept cutting it shorter to provide more force to reach that spot where it would catch the ball. I remember putting in a really stiff spring that I had kicking around. It definitely caught the ball; but was too strong for the mechanism to rotate to release locked balls.

This is the biggest pain in the ass to adjust on FH. I just had to keep tweaking and tweaking, using a stick to reach under all the ramps to push the wheel a fraction of an inch further, then tightening and testing in gameplay. And as soon as you think you've got it, you realize you didn't tighten the nut enough and it goes out of adjustment.

I just live with it on my game. It's not a difficult game so bounce outs make it just a little more challenging. I do wish there was an easier fix for it and the mechanism wasn't so damn hard to access.