Saturday 21 November 2009
DIY CNC Mill Controller for Stepper Motor Milling Machine
This addon to our CNC mill was made to allow manual control of the mills cnc stepper motors using a pair of 2 axis joysticks obtained from a broken radio control plane radio transmitter.
The circuit uses a 12 series PIC processor to sample the joystick position and determine a center point. This then sends one output to the mills motor controller for the direction which switches between 0V and 5V via a optical isolator and the second output from the PIC Processor gives a voltage which corresponds to the joysticks position between 0-5V which goes into a voltage to frequency chip which sends a pulsed output to the mills motor controller for the speed. This is also isolated using a a optical isolator to protect this new circuit when the PC is controlling the mill.
The finished hand controller with the 2 joysticks which came from a old RC plane controller.
The rear of the joysticks, we are only using 3 of the 4 channels for this project.
One of the three pcbs for the control box, we had a problem with the pcb layout software getting the output pins on the optical isolators backwards so they had to be mounted vertically and the wires crossed.
The mill motor controllers with the computers parallel port connection visible on the left side.