Saturday, February 23, 2008
10 hours later....
I ended my Thursday with an idea of how I was going to make the ball ejector for getting the marbles out of the ring at the top. I had something started, and spent that night thinking all I had to do was go ahead a finish it. Unfortunately, it did not work out that well. I worked on that particular design until about 3:00 pm, on Friday - I wanted to give up as it just did not work. In fact I remade that part 5, count them, 5 different times. All a failure. The main problem being the wire that was supposed to push out the marble didn't travel into the hole far enough. The secondary problem was I had to make it work, at any cost of time. Finally I scrapped what I had, and after something to eat, tried again. After all of the problems I had been having with the first design, I was starting to get an idea of what I needed to change to make it work.
This picture (above) shows the ejector pin fully extended into the hole. You can see that the pin coming out from the wood ring is just about to pass the lever, and let it fall back to it's resting position.
This is design that works. There is a pin sticking out under each hole. This pin pushes into an arm, that in turn pushes into the bottom of the three white bearings. Since the fulcrum is off-center, the top will move farther than the bottom is pushed. Meaning: The bottom is pushed in about 3/4", and the top will move out 1 1/4". This shot (above) shows the pin just about to push into the lever.
This photos shows the pin fully extended into the hole in the ring. The 1/4" rod that is now straight out is a counter weight. It's weight will make the arm return when the pin passes. It will work better than a spring because it will have less pressure, and gravity will never fail. The rubber is to keep it quiet when it drops back to it's resting position.
Finally, here's a view from the top. The white bearing on the right is to keep the ring in the same position at the top, and so that it cannot shift and rub on the ejector pin. Lots of testing and retesting to get to this point, but well worth it. It works flawlessly, and is a joy to watch. (now that it works!)
Now on to track, track and more track. : )