Hi chuck,
Here is the info, if you decide to build one.
Electronics
Encoder: LPA3806 Rotary Encoder two phases 600 pulses/rotation
Arduino: Pro Mini Atmega328P 5V 16 MHz
Display: Max7219 8-Digit display module
Power Suppy: 5 Vdc 1 A min
Programming:
USB Serial: FT232RL Usb to Serial adapter
Hardware:
Pulley
Spring
Bearing
Timing Belt
Timing Pulley
Arduino Code:
Attached file MillDROZ.txt (copy it to your Arduino system folder and rename it to .ino)
Drawing:
Attached file Encoder.txt (rename it to Encoder.dxf - the forum don't allow dxf files...)
Diagram:
You will need to download the Arduino IDE platform and learn the basics of it.
The Arduino Pro Mini is a simplified version of the traditional Arduino UNO. It has no USB port (cheaper and much smaller), but needs a adapter for programming, the FT232.
The USB to Serial adapater FT232 is used only for programming the Arduino Pro Mini. It is not used in operation; you will need only one for all your Arduino Pro Mini projects.
Wagner