Swindle Ball Tray

A Con Effect with a FANTASTIC Suprise Ending!
Extremely clever self-contained gimmicked tray controls the vanish & appearance at all times.
A tray, three cups (non-gaffed) and a ball are shown. The ball on the center of the tray is covered with one of the cups. The remaining two cups are placed on each side of the hidden ball.
Now, in the classic three shell and pea con, the cups are moved around. When the cup is lifted the ball is not there.
Another cup is lifted to show the location of the ball.

This repeated as many times as you want using the same or different spectator(s).
No matter how hard they try the ball is never where they think it is.
Now for the KICKER Ending: a ball appears under each cup!
The tray measures: 14" x 9"x 6".
You provide the cups.