The Ball Blocker

This little gizmo attaches to the ball trough under the apron. When you raise the playfield, the flag pops out and keeps the balls in the trough, instead of dive bombing your plastics. The design works for most WPC games.

Here it is in the down position. The balls can get out of the trough. And this is the up position. The playfield is vertical, the camera is contorted but the magic of computers makes the trough look level. But you can see that there is a ball trying to escape, but held back by the flag, which has deployed under the force of gravity.
First, remove the apron. Here you see teh ball blocker, waiting to be installed. Remove the highlighted screws, and the trough post. The ball blocker flag will replace the post, so put the post inside the machine for safekeeping.
Now, put the ball blocker over the trough holes and replace the screws. Put the apron back on, and you are done!