Presentation on theme: "CNC Programming “Milling” Module Objectives: 1) To use Topmill 2)To create NC programs for different milling operations."— Presentation transcript:
CNC Programming “Milling” Module Objectives: 1) To use Topmill 2)To create NC programs for different milling operations
G-Codes FunctionDescription G17,G18, and G19Working plane selection G40Cutter radius compensation OFF. G41Cutter radius compensation ON Left. G42Cutter radius compensation ON Right. G70Input system inch G71Input system metric G00, G01, G02, G03, G04, G54, G90, G91, G94 and G95 Are the same as explained in module 4. New important G codes:
G-Codes FunctionDescription G111Polar coordinate interpolation G147Approach with a straight line. G148Leave in a straight line. G247Approach with a quarter a circle. G248Leave with a quarter a circle. The following G-Codes and their relative slides will be used as a reference when solving some practical tasks in this module.
G17, G18, and G19 Used to select the working plane G17 XY Plane G18 ZX Plane G19 YZ Plane The tool axis is vertical to the working plane
What Is The Correct G-code To Select The Top Surface Of The Workpiece As a Working Plane ? G17
G41, G42 and G40 With G41 / G42 the tool traverse at equal distances to the programmed contour along its path. This distance is the dimension of the radius of the cutter. If the cutter is left to the contour this is programmed by G41 (This called cutter radius compensation left).
G41, G42 and G40 If the cutter is right to the contour this is programmed by G42. (This called cutter radius compensation right) To cancel the radius compensation use G40
G70 / G71 G70: The controller of the CNC milling machine reads the input values in imperial system (Inch) G71: The controller of the CNC milling machine reads the input values in metric system (mm)
G111 If we want to use polar coordinate system to move the tool, we need first to locate the pole (zero point of the polar coordinate system) measured from original workpiece zero point, this is done by G111. Then write the required movement in polar system by specifying the Angle (AP) and the radius (RP). Example: G111 X30 Y40 Z0 G01 RP=40 AP=60 F300
G147, G148, G247 and G248 Soft approach and leaving commands. The function of soft approach and leaving serves to approach the starting point of a contour tangentially irrespective of the position of the initial point. The function is mainly used in connection with the tool radius correction; however, it is not obligatory.
G147, G148, G247 and G248 G147 Approach with straight line G148 Leave in straight line. G247 Approach with a quarter a circle G248 Leave in a quarter a circle
Cycles CycleDescription Cycle 81Drilling; to make a hole in one phase. Cycle 83Deep Drilling; to make a deep hole, which requires introducing the tool with several phases. (Chip-breaking and chip removal). PocketTo engrave a circular or a rectangular area on a surface. HolesTo repeat a drilling operation following circular or linear contours.
Cycle 81 – Drilling Cycle To make a hole in one phase
To make a hole in one phase Example: Make a hole at point X20 Y20 to a depth = 10mm
Example of CNC Programming What Must Be Done To Drill A Hole On A CNC Vertical Milling Machine? Given That: Absolute Positioning Mode, Cutting Tool No. 1, Spindle Speed 1000 RPM, Clockwise Direction Of Rotation At Feed Rate 200 mm/min. Hole Position X10, Y12, And Depth Of Hole 10 mm.