I have acquired the necessary electronic components to implement my plan for automating the traverser. Working with stepper motors is a new thing for me so I wanted to start in on that sooner to qualify the technical risk aka figure out if it can be done. In the interests of speed, I decided to go with fast and effective for the prototype.
Initial major components are:
- A NEMA23 stepper motor which the size typically used by small CNC machines. The traverser table will be rolling on drawer slides and hopefully this motor will have enough torque to move the table when loaded with cars and loco.
- A Big Easy Driver board to control the motor. This motor can draw up to 2 amps so you can’t drive it directly from microcontroller PWM outputs like a small servo. This driver is one that has good Arduino support.
- An Arduino Uno R3 microcontroller board. This is major overkill for this application in terms of processor power and functionality but the quickest to get something running. Final version will probably be an Arduino mini but that board doesn’t have on-board debugging support so I wanted to defer that until later.
I am going to use the Arduino development environment with its associated cornucopia of software and community support. I would not base a commercial product on Arduino but nobody is paying me for this so I am trying to focus on the model railroad goal and avoiding the temptation to start from scratch firmware-wise.