My Challenge to Make a Marble Run Machine – Think, Think

A new idea always comes to mind in the middle of the night. I don't know why. 

Two days ago, I woke up in the dark and suddenly an image of a new idea popped into my mind. I got up, grabbed a pen, and drew a rough sketch. I thought the idea was brilliant. However, I knew I tend to overrate my ideas, especially an idea I think of in the middle of the night.
It's because I've been thinking about the mechanism of the marble run machine for a long time and couldn't find a good one at all. Therefore, I have a tendency to pin my hopes on the new idea I had just thought of. The idea I had thought of was my light of hope, but it was too early to rejoice.

The following day, I reconsidered the idea of my light of hope. I thought of various issues that could possibly come up. After consideration, my light of hope, which was supposed to be a giant light bulb, shrank to a small bulb placed 10 m away. Things like this have always happened.

Having said that, I may find a function I can use if I devise this idea. It's the most likely idea I've ever had. All right, I won't give it up yet.

Today is my birthday. I want to give myself the best gift, a mechanism that works perfectly. If I could solve this issue, it means I solved the most difficult part of the mechanism of my marble run machine. I want to change a small bulb into a bright big bulb.

Every time I cannot solve an issue, I recall one of the movies I saw a long time ago. It was the movie in which comedian John Candy acted. I don't remember the title of the movie. In the movie, he was in a critical situation, hanging from a rope and said, "Think, think."
Now is the time for me to think.

Let me start by drawing a picture of the mechanism on 3D software and make sure whether it works or not. I hope it works well.