OK, you asked about the internal workings. I'm not sure if you mean the mechanicals, or the electronics. But, they have to work together, and the stepper motor is the fundamental basis around which most of these machines are made.
The mechanical parts are simple...if it moves by turning a handle, it can move by turning a motor. It's just how you index the rotation of the motor that becomes an issue. The stepper motor is the solution.
A stepper motor is a special kind of motor that moves 1 "step" on command. The step is a precise portion of a full rotation, often 1.8 degrees. (200 steps per revolution) Your computer sends out a bit pattern through the parallel port, consisting of 1s and 0s...this instructs a "black box" driver circuit to make your motor move 1 step at a time, and in a certain direction.
Do you want to build your own driver circuitry, or do you want to buy it? Lots of good companies make them...one of the best is Gecko, run by a guy named Mariss Freimanis. He goes out of his way to help people.
Are you capable of building the mechanical parts of the machine? They're not that complicated...if you're mechanically inclined. One of the best resources on the net is run by the guy who inspired a lot of us...he has projects called "routezilla" and "morph." He shows LOTS of pictures, and sells plansets for his machines, as well as a well thought of driver circuit which uses a PC power supply for power. It's called the Piker. A quick search on google will turn up his name and his site URL.
If you give us a starting point for discussion, we can all be of help.
-- Chuck Knight  |