common tasks individual work

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2 Course is focused fundamental possibilities of automatization of machine tools and automatization of programme preparation for CNC machine tools. 1+2, CA classified assessment - 3 credits Presentations Exercises common tasks individual work

3 Project work will be explained during exercises evaluation (work must be completed and evaluated by more than 50%) Test from knowledge presentations and recommended literature test itselft more than 50% total is a sum (50 50%) from both

4 1+2, 1 hour of presentation, 2 of exercise => weeks (13+26) => 6 presentations + exercises. presentation explain the work on exercise => presentation will be together on the beginning of the semester and later during semester. and then you will have time to make the task and individual work!

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6 Work on conventional machines is replaced by automated work on automatic machines. These machines are working without human control with higher speed, precision, safer and more productivly than humans. But where did it start?

7 Is connected with the rising demands of society and industry development. Is the way to intensification of manufacturing increasing productivity, improving quality and lowering costs Is the way to improvements in manufacturing technology, spreading the technological possibilities and way to make the inovation cycle faster.

8 Tool management Tool change Tool movements Spindle start, devices start Material loading Finished piece remove

9 Machine tools: general-purpose, manually operated (conventional); - The leading power is the worker

10 Machine tools: automated: a) fixed automation mechanisms: cams, gear wheels, links, levers, arms; mechanical stops, limit switches, etc. b) flexible automation program control, numerical control

11 NC/CNC machine consist of 3 basic elements. List of instructions NC code a mix of alphabecial and numerical information. Contaion information about movements, feed, speed, tool change and other machine functions (cooling, measuring) Control unit - control system converts the program into signal for machine and send them to machine (PLC controller) NC code Control unit (system) Machine Drive motor Sensing device

12 NC/CNC machine consist of 3 basic elements. Machine tool fitted with drive motor to operate slides, support and spindle. Also with switches to start/stop specific functions Sensing device optional(closed circuit)- sensing device control if a specific demand was fullfilled. Support feed, Table position etc. NC code Control unit (system) Machine Drive motor Sensing device

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14 Three types of motion 1) point-to-point motion tool is moved to specific location, path or speed of move between location is not controlled. (drilling) 2) Linear control movement along one of the axes of the machine. 3) Contouring control movement can be made in two or more axes simultaneously.

15 Point-to-point control Linear control Contouring control (continual) drilling milling machines, lathes machining c.(milling, turning)

16 MC combine a number of different machining processes in one operation

17 Programming of machine tools

18 Machining on CNC machines is controled by a NC code. NC code is a list of instructions for the machine and also for the operator. Instruction are executed in time order. NC code must have a specific format so that the control system of machine is able to read it.

19 The tool in machine is moving in workspace. The position of the tool is given by coordinates. We are using different coordinate systems. If we set some coordinates in NC code, the machine moves the tool to the specified place.

20 Basic is orthogonal system Z Y X

21 Z axis is usually axis of spindle a X axis is the working axis, or the longest! Z Y X

22 Z axis is usually axis of spindle a X axis is the working axis diameter!!! X Z

23 To set the position we can add rotation along the axes. Z Second set of coordinates U,V,W resp. P,Q,R etc. C Y B X A

24 Refernce point a specific point on machine with given coordinates. Not always in the workspace of machine. A special commang G98

25 Ways how to define a movement a) Absolute programing position is in all point expressed as a distance from zeropoint b) Incremental programing position is expressed as a change from last postion

26 Absolut G90 X0 Y0 Z50 G0 X15 Y70 Z50 G1 X15 Y70 Z0 G1 X25 Y70 Z0 G0 X25 Y70 Z50 G0 X0 Y0 Z50 Incremental G91 G0 X15 Y70 Z0 G1 X0 Y0 Z-50 G1 X25 Y0 Z0 G1 X0 Y0 Z50 G1 X-45 Y-70 Z0

27 Structure and form of NC code is standardized by international standard - ISO 6983 Numeric control programs formating Differences between different control system manufacturers and differences between versions.

28 Lines (blocks) Words Word has a meaning and value part S 1500

29 ISO is standardized code (G code) Some manufacturers devoloped their own standard for NC code native standard Mazak Mazatrol Heidenhein itnc Siemens - Sinumeric

30 Heading lines Definition of relation between coordinate system of CNC machine and program, type of programing, work mode, working conditions Program body Cutting and non-cuting moves, main program and subprograms, tool changes Ending lines Tool return to home point, change to first tool, coordinates reconstruction

31 Subprograms A link to another then the following line is entered into main programm. This subprogram is executed. After finishing this program we return to main program a we contiue until end of main program(m30)

32 Manual/Hand programing Shopfloor programming Automated programing

33 Editors are used. Program is written manually (by hand) line after line. Used for simple parts (but complex too) Toolpath is exactly defined Program can be adjusted to save time Can use canned cyles Can be parametrized Used in mass production

34 We need to know the functions: (many more function exist) Movement functions: G00 rapid movement G01 linear interpolation/movement G02/03 circular interpolation G40 diameter compensation off G41 diameter compensation on /right handed G42 diameter compensation on /left handed Support and help functions: M06 tool change M03/04 spindle start CW/CCW M05 program stop M30 program end

35 Specilzed editors Predator G-code editor G Wizard Mikronex

36 Somewhere in between manual and automated Uses cycles with parameters We have to edit these parameters manually But the NC code is generated automatically No postprocessing

37 Control system use programming on machine - No costs (together with machine) - Fast use (macros) - Time waste (program x work) - Comfort (on machine x in office with PC) - Shape limitations Heidenhein

38 Work with the sequential NC code preparation Uses CAM (Computer Aided Manufacturing) software For all parts including complex shapes We dont need to compute the toolpath We need correct postprocessor

39 Partprogram workpiece, material, cutting conditions, tools Procesor according to technology CL data virtual toolpaths on virtual machine Postprocesor translator for the specific CAMcontrol systém-machine combination NC code toolpaths of a real tool on a real machine Partprogram CL-data NC-kód Proceso r Postproceso r

40 is Computer Aided Manufacturing (machining) From simple 2-axis turning up to multiaxis machining Feature or technologically oriented Special types of CAM for special purpose Live presentation

41 2D just in two axis - turning 2,5D two axis, but in layers not simultaneously 3D three axes simultaneously multiaxis 4D four axis - one rotary axis (rotary table) 5D five axis - maching (two rotary axes)

42 CAM software uses Strategies Strategy is a general plan how to move the tool durign machining Continual development Roughing offset, raster (Zig-Zag method) plunging Finishing strategies pencil milling, streaming, rest material maching

43 NX (Siemens PLM software) Catia (Dassault systémes) both 10% market share PowerMill, FeatureCAM, ArtCAM (Delcam company),inventorcam (Autodesk) Wildfire Pro/Ingineer (PTC) 5% EdgeCAM, SurfCAM, SolidCAM, MasterCAM, OneCNC, ESPRIT, GibbsCAM

44 Simulation is used to control generated toolpaths for following reasons: - Colisions - Undercuts (or rest material) - Postprocesing check

45 NX

46 We can do complex shapes, no need to calculate control points We can use simulation and verification We can change the tool easily But We need postprocessor Expensive (SW, computer, learning ) Program is always longer (again expensive)

47 ArtCAM FeatureCAM

48 Projects - Common same tasks for all - Individual own selection of part and individual work on it. Evaluated. Test from theory of automation and programming