well this is for the "I have to know how it works" guys. the tower is a metal tube. I glued HO gauge rails to the sides. there is a set of wheels inside the cabin that guide the cabin up. inside is a small radio controled servo that picks up power through the rails. this is what turns the cabin. the cabin is made from plastic and plumbing parts. on the bottom of each step (where the door is) I have a magnet glued to the bottom. at the base of the tower I have a reed switch that is hot all the time. as soon as the cabin lifts, it starts to turn. when it comes down, it will stop when one of the magnets trips the switch.
the lifting is done with a radio controlled servo. I removed the stop control and circuit boards so that they just turn. I then built a wood barrel to wind up the string on. the string is heavy duty sewing thread. there is a bolt attached to the end of the barrel and there is an aluminum slider that contacts two switches. these are the bottom and top limit switches.I used an 8-32 bolt and it turns 17.5 times from bottom to top.
the PLC reads the bottom limit switch and starts a loading timer. then it turn on the servo and starts to raise the cabin. once the magnet disengages the reed switch, the cabin spins. when the top limit switch is contacted, the PLC starts a timer that lets it spin for a certain time. I need to increase that a hair as the real one turns 3 revolutions. then the PLC turns on a DPDT relay that reverses the servo motor voltage and turns on the servo, lowering it. when the bottom limit switch is hit, and the magnet goes over the reed switch the cycle starts again.
so that's how the whole thing works. everything is made by hand and it took me about 5 months to work out the details and build.
I'm glad you like it and I have to thank everyone that has given me helpful advice on the coding. I built it, but you guys made it work!
Bob.........
