IPAN 4th Project Meeting Lisbon, 10th until 14th of March 2014 …teacher Workshop 1

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project CNC Fundamentals (Milling) 1. The CNC Milling Machine - Application; Task sequence; Main Components 2. The Axes System - Direction & Senses - Datums: Machine & Workpiece reference point - Type of coordinates: absolute and incremental (Exercise 1 & 2) 3. Programming -Program format -Program begin; Definition of workpiece blank; Technological data; Geometrical data; Program end -Key data & format -Preparatory function; feed function; Spindle function; Tool function; Miscellaneous function -Interpolation Functions -Positioning (rapid traverse) -Linear Interpolation (Exercise 3) -Circular Interpolation (Exercise 4) Workshop 1

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project E xercise E xample just take your notes Pratical work (do it your self) step by step (all together) Lets break some tools! M achining What does it means… Symbols

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals CNC technology has reached a stage of having become omnipresent. A lot of people can hardly imagine how important these technologies are in their lives: it is present in products and objects of everyday life as e.g. cars, airplanes, components of machines of all types, moulds for tools used for household machines, cell phones, toys, medicine prosthesis, etc. CNC Technology includes machining tools such as lathes, multi-axis spindles, wire electrical discharge machines and milling machines, where the functions formerly performed by human operators are now performed by a computer-control module. The professionals associated to this skill use computer numerically controlled (CNC) machines to cut and shape precision products, as mentioned above. To form a finished part the cutting process can be started from a solid block, premachined parts or castings. Thus the abbreviation (CNC) refers to a computer ("control") that reads instructions ("G-code") and drives the machine tool, a powered mechanical device ("milling machine"), used to fabricate components by the selective removal of material. A programme with “G-codes” is required and generated manually and/or automatically using CAD/CAM software followed by the necessary machining operations. To achieve the finished part the CNC Milling professionals undertake a sequence of essentials activities:. Interpret engineering drawings and follow the specification.. Generate a program (logical, process plan) with a CAD/CAM system and/or G-code.. Set-up the tooling, work holding device, and work piece on the CNC machining centre.. Manipulate cutting conditions, based on the properties of metal and tooling.. Operate, inspect and maintain the accuracy of dimensions within the tolerances.. Optimise the process taking into account the production type: large quantities of one part, small batches or one-of-a-kind items. Today a wide range of industries require CNC milling professionals to program, operate and keep sophisticated milling machines running in an efficient and reliable way. Large enterprises such as automobile, medium-sized enterprises, such as mould making and small enterprises on maintenance field are some of many examples where the CNC milling professional plays a key role to the success of metalwork industry. “Text taken from the technical description (Skill07 – CNC Milling) of the Worldskills competition” Thus the abbreviation (CNC) refers to a computer ("control") that reads instructions ("G-code") and drives the machine tool, a powered mechanical device ("milling machine"), used to fabricate components by the selective removal of material. A programme with “G- codes” is required and generated manually and/or automatically using CAD/CAM software followed by the necessary machining operations.

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals CNC Technology (a wide application) Milling Measuring Welding Robot Laser Sheet Metal Punching Sheet Metal Painting Robot

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals Application… To produce different types of parts such as: <moulds for tools used for : Household machines, cell phones, toys, etc> The process… By removing/cutting material knee prosthesis Femoral component Initial data… … a paper drawing … a digital drawing … a prototype

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals Tools & Cutting Data Machine Tool Power, axes travel range, etc Machine Tool Power, axes travel range, etc Inspect Maintain the accuracy of dimensions within the tolerances Inspect Maintain the accuracy of dimensions within the tolerances Machining Features (operation) Clamping & Workholding device Engineering drawing interpretation

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals Tasks Sequence… Interpret engineering drawings and follow the specification Process Planning Programming Machining. Identify main dimension and secondary dimension. Identify the standard. Identify ISO standard for surface finish. Identify ISO standard for form and positional tolerances. Identify and set the different machining features and its executional sequences. Correctly select the type of fixture system that best suits the operational requirements. Adequate selection of the cutting tools, for machining the required material and operation. Defining the cutting parameters as a function of the operation sequence, material type and type of operation. Select the best methods according to the production type and part specification. Create a program using G-Codes. Create a program using a CAD/CAM system taking into account the format of the initial data:. Start with a drawing in paper format - creation of the geometry in wireframe and/or surface and/or solid. Start with a file in wireframe and/or surface and/or solid and import it to CAD/CAM system. Using the parametric programming system. Use the stipulated processes for mounting the tools and accessories on the equipment.. Identify and designate the different machining processes on CNC milling machine. Identify and designate the functional parameters for operation on CNC milling machine. Defining and adjusting of cutting parameters as a function of the operation sequence, material type, type of operation and CNC machine tool. Use of the different programming techniques for CNC milling machine (CAM included) “Text taken from the technical description (Skill07 – CNC Milling) of the Worldskills competition”

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals Picture from Heidenhain HIT Software The CNC Milling Machine Display unit and keyboard, electronic handwheel Control ATC – Automatic Tool Change Working table Linear Encoder Recirculating ball screw 55 Convert a rotational movement into a translational one Motor Spindle Head Machine Base

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals How it works in general…

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals The axes system… Direction Right-Hand Rule of Coordinates Senses Thumb (X-axis), Forefinger (Y-axis) and Middle finger (Z-axis) 3-axis Milling Machine: - The +Z-axis points into the spindle Machine coordinate system is described based on Cartesian system X, Y, Z

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals The coordinate system… Coordinate at any time is designated in one of two ways: Absolute Coordinate System:. Calculate the distance relative to the origin (X0, Y0, Z0) Incremental Coordinate System:. Calculate the distance relative to the last point (2,3) (-3,1) (-1,-2) y x (0,0) A B C (1,1) (-4,2) (1,-5) y x (0,0) A B C yByB xBxB yCyC xCxC

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals XYXY Abs.Inc. E xercise 1

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals E xercise 2 XYZXYZ Abs.Inc.

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals Datums: Machine & Workpiece reference point All CNC Machine Tools require a reference point to calculate the coordinates! The Machine Datum M is the origin for the machine coordinate system. It is defined by the machine tool builder. The dimensions of the path measurement system refer to this point The Workpiece Datum W is the most important datum for NC programming. The machine operator sets it to a useful position on the workpiece

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals Program format: Processed one line (*) at a time sequentially (*) Line=Block Common Format of a Block Block number N10G90 G01 X20 Y56.89 F300S3500T04M03 N10 G90 G01 X20 Y56.89 F300 S3500 T04 M03 Preparatory Function G words specify the mode in which the milling machine is to move along its programmed axes. Dimension Words Distance or position in X, Y, Z direction F – Feed rate (inches per minute or millimeters per minute) Rate at which cutting tool moves along an axis. M – Miscellaneous functions M words specify CNC machine functions not related to dimensions or axial movements. Spindle Function S – Spindle speed (rpm – revolutions per minute) Controls spindle rotation speed. Tool Function: T – Tool number Specifies tool to be selected.

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals Conversational 0 BEGIN PGM 7777 MM 1 BLK FORM 0.1 Z X-50 Y-50 Z-20 2 BLK FORM 0.2 X50 Y50 Z0 3 TOOL CALL 3 S L Z+80 FMAX M3 5 L X+10 Y+10 FMAX M8 6 L Z-2 F200 7 L Y30 F L X40 Y45 9 L Z50 FMAX 10 M30 11 END PGM 7777 MM ISO G-codes Program format: Two different examples N0 7777; N1 G90 G94 G54 G80 G40 G21; N2 M6 T01 N3 M3 S5000 N4 G0 Z+80 N5 X+10 Y+10 M8 N6 G1 Z-2 F200 N7 Y30 F1000 N8 X40 Y45 N9 G0 Z50 N10 M30 Block Number Preparatory Function (geometrical commands) Dimension Words Spindle Function Tool Function Miscellaneous Functions Feed rate Function

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals Programming – Conversational Heidenhain The command syntax: BLK FORM 0.1 Z X Y Z BLK FORM 0.2 X Y Z BLK FORM 0.1 Z X______Y _______ Z_____ BLK FORM 0.2 X ________ Y _______ Z______ BLK FORM (definition of the workpiece blank) 1 Picture from Heidenhain HIT software

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals Programming – Conversational Heidenhain Tool Definition 2 The command syntax: TOOL CALL Z S F TOOL CALL 2 Z S 3000 F 150 The main functions The main miscellaneous functions (M codes) (Spindle CW) M3M4 (Spindle CCW) M8M9 (Coolant ON)(Coolant OFF) M13=M3+M8M14=M4+M8 M30 (Program END) M6 (ATC-Moves the tool to the Spindle )

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals Programming – Conversational Heidenhain Linear Movements 3 Rapid Positioning (Tool movements outside the workpiece at a rapid Traverse FMAX) Linear Interpolation (Linear movements parallel to the axes or diagonal at a defined feed F) The command syntax: L X____Y____Z____FMAX L X34.56 Y Z-10. FMAX L X____Y____Z____F____ L X34.56 Y Z-10. F3000

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals E xample 1 (step by step) 1 y x x z Raw size Contour 10x10 0 BEGIN PGM EXA1 MM 1 BLK FORM 0.1 Z X-10 Y-10 Z-20 2 BLK FORM 0.2 X70 Y70 Z0 3 TOOL CALL 2 Z S L M6 5 L X10 Y10 FMAX M13 6 L Z5 FMAX 7 L Z-10 F50 8 L X10 Y30 F200 9 L X30 Y60 10 L X60 Y60 11 L X60 Y30 12 L X30 Y30 13 L X30 Y10 14 L X10 Y10 15 L Z50 FMAX 15 L M30 16 END PGM EXA1 MM

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals E xercise 3 Tool: Drill Dia. 8mm; S=2500; F120 Raw size: 100x100x20 Programme name: EX3

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals Circular Interpolation 4 Programming – Conversational Heidenhain Circle with Radius (circular movements in clockwise or counterclockwise direction at a defined feed F with a preset radius. ) The command syntax: Clockwise direction = DR- Counterclockwise direction = DR+ CR X____Y____R+/-___ DR +/- F___ CR X10 Y20 R20 DR- F300CR X30 Y10 R20 DR+ F300 ClockwiseCounterclockwise R + IF the range is less than 180º R - IF the range is greater than 180º Picture from Heidenhain HIT software

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals Circular Interpolation 4 Programming – Conversational Heidenhain The command syntax: Circles (circular movements can be programmed by entering the center point, end point and direction of rotation at a defined feed F ) CC X____Y____ (center point of the arc) C X ___ Y____ DR +/- L X10 Y14 F300 CC X25 Y25 C X36 Y10 DR+ Example: Picture from Heidenhain HIT software

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals E xercise 4 Tool: Mill Dia. 6mm; S=5000; F100 Raw size: 100x80x20 Programme name: EX4

4 th Project Meeting Lisbon, 10 th until 14 th of March 2014 IPAN Project Workshop 1 – CNC Fundamentals M achining Now, lets machine something!