The cable winding pulley was the most complicated part of the machine due to it’s multiple set screws, flat surfaces, precise bore, and threading. One set screw holds the pulley on the shaft. The other set screw holds the cable firmly attached to the pulley.
Here is a picture of the pulley mounted to the DMM Tech Servo Motor. In the background you can see the cable go up through the top of the machine, over the free pulley, and back down to hold the main slider mechanism.
Today we devised a way to (hopefully) raise the marbles from the bottom of the track to the top using a servo motor. It is rather obvious at this point that we did not plan our initial track high enough and the end of it is too low. Oh well, version 1 is usually that way, right?
The kids and I are building a Arduino powered marble roller. It is a “demo” project for us to learn how to use servos, steppers, input, output, lights, transistors, h-bridges, and so on and so forth.
Hot-glue and foam-board are a great prototyping material!