My Hypothesis is that I can catch leprechaun using a pulley in my trap.
First the leprechaun will climb up the ladder. Then he will step on the pressure pad. I have hook under my pressure pad and the pressure will make the string detach from the pressure pad. Then it will go up the pole and make the cup fall on top of the leprechaun.
I had to change the way my pulley worked.
My conclusion is I was wright about the pulley I just needed a pressure pad but,I didn't catch a leprechaun.