DMFD 3333 – CNC TECHNOLOGY

DMFD 3333 – CNC TECHNOLOGYDMFD 3333 – CNC TECHNOLOGY

DMFD DMFD 33333333 – CNC – CNC TECHNOLOGYTECHNOLOGY

PROCESS PLANNING/ PROGRAMMING

PROCEDURE


GOALGOAL

- Completion of all instruction in - Completion of all instruction in the form of a program that will the form of a program that will result in an error free, safe and result in an error free, safe and efficient CNC machining.efficient CNC machining.


All planning must be approached in a All planning must be approached in a logical waylogical way and and methodical waymethodical way

Decision: Decision: What task to be done?What task to be done?

What goals?What goals?


PROCESSPROCESS

1.1. Study of initial information (drawings)Study of initial information (drawings)2.2. Material evaluationMaterial evaluation3.3. Machine tool selectionMachine tool selection4.4. Sequence of machining operationSequence of machining operation5.5. Tooling selection and arrangement of cutting toolTooling selection and arrangement of cutting tool6.6. Setup partsSetup parts7.7. Technological dataTechnological data8.8. Determination of tool pathDetermination of tool path9.9. Program writing and preparation to transfer to CNCProgram writing and preparation to transfer to CNC10.10. Program testing and debuggingProgram testing and debugging11.11. Program documentationProgram documentation


PROCESSPROCESS

1.1. Study of initial information (drawings)Study of initial information (drawings)2.2. Material evaluationMaterial evaluation3.3. Machine tool selectionMachine tool selection4.4. Sequence of machining operationSequence of machining operation5.5. Tooling selection and arrangement of cutting toolTooling selection and arrangement of cutting tool6.6. Setup partsSetup parts7.7. Technological dataTechnological data8.8. Determination of tool pathDetermination of tool path9.9. Program writing and preparation to transfer to CNCProgram writing and preparation to transfer to CNC10.10. Program testing and debuggingProgram testing and debugging11.11. Program documentationProgram documentation

Study of Information (Drawings)Study of Information (Drawings)

Very important document where it Very important document where it physically visual the shape, physically visual the shape, dimensions, tolerances, surface finish dimensions, tolerances, surface finish and many other requirements such and many other requirements such as number of parts and other as number of parts and other secondary processessecondary processes

DMFD 3333 – CNC DMFD 3333 – CNC TECHNOLOGYTECHNOLOGY


Material EvaluationMaterial Evaluation

Typical material is raw and Typical material is raw and unmachined: billet, bar, plate, forging, unmachined: billet, bar, plate, forging, casting etccasting etc

The size and shapes of the the material The size and shapes of the the material determine the type of fixturingdetermine the type of fixturing

Machinability: charts for recommeded Machinability: charts for recommeded speed and feed for most common speed and feed for most common materialmaterial

Machining SequenceMachining Sequence

1.1. Order of machining sequence.Order of machining sequence.2.2. Technical Skill and and machine Technical Skill and and machine

shop experience is important.shop experience is important.3.3. The machining sequence must be in The machining sequence must be in

logical order.logical order.4.4. Determine the shape of the part.Determine the shape of the part.


Machining SequenceMachining Sequence

1.1. Order of machining sequence.Order of machining sequence.2.2. Technical Skill and and machine Technical Skill and and machine

shop experience is important.shop experience is important.3.3. The machining sequence must be in The machining sequence must be in

logical order.logical order.4.4. Determine the shape of the part.Determine the shape of the part.



Work Holding DevicesWork Holding Devices


The method of holding the parts to be The method of holding the parts to be machine on the machine so that:machine on the machine so that:

1.1.Parts is correctly orientated Parts is correctly orientated

2.2.Dimension is not distortedDimension is not distorted

3.3.Locate part with respect to its datumLocate part with respect to its datum

4.4.Proper locating and clamping Proper locating and clamping ensures repeated products and ensures repeated products and accuracy.accuracy.


Work Holding devices for milling:Work Holding devices for milling:

1.1.ViceVice

2.2.Angle plateAngle plate

3.3.Direct clamping or fixturesDirect clamping or fixtures

4.4.ChuckChuck

5.5.Tomb stonesTomb stones


VICEVICEMost commonly used for simple shape Most commonly used for simple shape

machiningmachiningManually, air or hydraulically operatedManually, air or hydraulically operatedMount on table so that it is parallel to its Mount on table so that it is parallel to its

x and y axisx and y axisMovable jaw should not be used as a Movable jaw should not be used as a

datum as it movesdatum as it moves


ANGLE PLATEANGLE PLATEFor work that need to be held at 90For work that need to be held at 90oo

angle to the axisangle to the axis

L shaped cast iron or steel that has L shaped cast iron or steel that has tapped holes or slots to provide for tapped holes or slots to provide for clamping purposesclamping purposes

Suitable for horizontal machining Suitable for horizontal machining centrecentre


CHUCKCHUCK

Three jaw chuck used to hold Three jaw chuck used to hold cylindrical workpiece on machine cylindrical workpiece on machine tabletable


DIRECT WORK MOUNTINGDIRECT WORK MOUNTING

Used to hold big or having odd Used to hold big or having odd shaped workpiecesshaped workpieces

Bolted directly to the tableBolted directly to the tableRequired ingenuity and expertiseRequired ingenuity and expertise


FIXTURESFIXTURES

Used in the following cases:Used in the following cases:The stock require some periphery The stock require some periphery

machiningmachiningThe stock is too large to be held by a The stock is too large to be held by a

machine vicemachine viceNot rectangular in shape.Not rectangular in shape.


TOMB STONETOMB STONE

Allow multipart to be held on any or all Allow multipart to be held on any or all of its parts.of its parts.

Manual or power clamping can be usedManual or power clamping can be used

Held on rotating machine pallets so Held on rotating machine pallets so that each side could be represented.that each side could be represented.

Increase productivity.Increase productivity.


MILLING PROGRAMMINGMILLING PROGRAMMING


TYPICAL PROGRAMTYPICAL PROGRAM

O002 O002 Program NoProgram NoN1N1 G20G20 Unit setting in different blockUnit setting in different blockN2N2 G17 G40 G80 G49 G17 G40 G80 G49 Initial Setting and Initial Setting and

cancellationcancellationN3 N3 T01 T01 Tool 1 in waiting positionTool 1 in waiting positionN4N4 M06M06 Tool 1 into spindleTool 1 into spindleN5 G90 G54 G00 X.. Y… Z.. M3 TO2 N5 G90 G54 G00 X.. Y… Z.. M3 TO2 T01 T01 restart restart

block T02 into waiting positionblock T02 into waiting positionN6 G43 Z2.0 H01 M08 N6 G43 Z2.0 H01 M08 Tool lgth offset coolant onTool lgth offset coolant onN7 G01 Z… F… N7 G01 Z… F… Feed to Z depthFeed to Z depth(….Cutting tool motion with tool 1)(….Cutting tool motion with tool 1)


N33 G00 G80 Z2.0 M09 N33 G00 G80 Z2.0 M09 Clear above part – coolant Clear above part – coolant offoff

N34 G28 Z2.0 M05 N34 G28 Z2.0 M05 Home in Z only coolant offHome in Z only coolant offN35 M01 N35 M01 Optional stopOptional stop--------N36 T02N36 T02 Tool 2 in waitingTool 2 in waitingN37 M06N37 M06 Tool 2 in spindleTool 2 in spindleN38 G90 G54 G00 X..Y.. S.. M03 TO3 N38 G90 G54 G00 X..Y.. S.. M03 TO3 T02 start block T02 start block

T03 in waitingT03 in waitingN39 G43 Z2.0 H02 M08 N39 G43 Z2.0 H02 M08 Tool lgth offsett coolant onTool lgth offsett coolant on(N40 G43 G01 Z-…F..)(N40 G43 G01 Z-…F..) Feed to Z depthFeed to Z depth………….Cutting motion with tool 2.Cutting motion with tool 2

N62 G00 G80 Z2.0 M09N62 G00 G80 Z2.0 M09N63 G28 Z2.0 M05N63 G28 Z2.0 M05N64 M01N64 M01……..N65 T03N65 T03N66N66 M06M06N67 G90 G54 G00 X.. Y.. S..M03 T01N67 G90 G54 G00 X.. Y.. S..M03 T01N68 G43 z2.0 H03 M08N68 G43 z2.0 H03 M08(N69 G01 Z-…F…..(N69 G01 Z-…F…..…………..Cutting motion with tool 3..Cutting motion with tool 3……



N86 G00 G80 Z2.0 M09N86 G00 G80 Z2.0 M09

N87 G28 Z2.0 M05N87 G28 Z2.0 M05

N88 G28 X.. Y..N88 G28 X.. Y..

N89 M30N89 M30

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Preparatory CommandPreparatory Command

Identify as G codesIdentify as G codes To presetTo preset or or to prepareto prepare the control the control

system to a certain desired system to a certain desired condition or to a certain condition or to a certain modemode or or statestate of operation of operation



Description and PurposeDescription and Purpose

e.g. N7 X200 Y10e.g. N7 X200 Y10 –end position of the –end position of the cutting tool does not show cutting tool does not show coordinates are absolute or coordinates are absolute or incremental, imperial or metric, incremental, imperial or metric, rapid or feed… hence the block is in rapid or feed… hence the block is in complete complete

Example AExample AN7 G90 X13 Y10N7 G90 X13 Y10

Example BExample BN3 G90N3 G90N4 ….N4 ….N5…..N5…..N6…..N6…..N7 G00 X13.0 Y10.0N7 G00 X13.0 Y10.0



EXAMPLE CEXAMPLE CN3 G90 G00N3 G90 G00N4 …N4 …N5 …N5 …N6 ...N6 ...N7 X13.0 Y10.0N7 X13.0 Y10.0

EXAMPLE DEXAMPLE DN2 G90N2 G90N3 G00N3 G00N4 …..N4 …..N5 ….N5 ….N6 ….N6 ….N7 X13.0 Y 10.00N7 X13.0 Y 10.00


Will there be any difference in Will there be any difference in motion in all the example ?motion in all the example ?


NO – there is no change in G codes NO – there is no change in G codes between block N4 and N6between block N4 and N6

One G codes in a modal will replace One G codes in a modal will replace another g code from the same groupanother g code from the same group


G CODES IN A BLOCKG CODES IN A BLOCK

Several preparatory function may be Several preparatory function may be used in a single block, providing they used in a single block, providing they are not in a logical conflict with each are not in a logical conflict with each otherother


Modality of G commandModality of G command

N3 G90 G00N3 G90 G00

N4 X0N4 X0

N5 Y20N5 Y20

N6 X15 Y22N6 X15 Y22

N7 X13.0 Y10.0N7 X13.0 Y10.0


For a command to be a modal, it For a command to be a modal, it means it has to remain in a certain means it has to remain in a certain mode until cancel by another modemode until cancel by another mode


Conflicting command in a blockConflicting command in a block

It is impossible to have rapid motion It is impossible to have rapid motion and a cutting motion in one block e.g and a cutting motion in one block e.g G00 and G01G00 and G01

- The latter will be used if accidentally - The latter will be used if accidentally usedused


Word Order in blockWord Order in block

G codes are normally programmed at G codes are normally programmed at the beginning of a blockthe beginning of a block

e.g. N40 G91 G01 Z-1 F200e.g. N40 G91 G01 Z-1 F200


GROUPING OF COMMANDGROUPING OF COMMAND

Commands cannot be in the same Commands cannot be in the same block: G00, G01, G02, G03block: G00, G01, G02, G03

Any G code from a given group Any G code from a given group automatically replaces another G automatically replaces another G code from the same groupcode from the same group



MICELLANEOUS MICELLANEOUS FUNCTIONFUNCTION


M code M code – Miscellaneous function– Miscellaneous function

- machine function (not all)- machine function (not all)


Machine Related FunctionMachine Related Function

Spindle rotation Spindle rotation CW or CCWCW or CCW

Gear range changeGear range change Low/medium/highLow/medium/high

Automatic tool change ATCAutomatic tool change ATC

Automatic Pallet change APCAutomatic Pallet change APC

Coolant operation Coolant operation ON or OFFON or OFF

Tailstock or Quill motion IN or OUTTailstock or Quill motion IN or OUT


PROGRAM RELATED FUNCTIONPROGRAM RELATED FUNCTION

Control of machine function Control of machine function

Control of the program functionControl of the program function


SPECIAL MDI FUNCTIONSPECIAL MDI FUNCTION

Manual Data Input (MDI) – used to Manual Data Input (MDI) – used to program from the controller – simple program from the controller – simple and repetitive process. M funcion and repetitive process. M funcion cannot be programmed.cannot be programmed.


M FUNCTION IN A BLOCKM FUNCTION IN A BLOCK

Only ONE function in a blockOnly ONE function in a block

Each M function is designed logically – Each M function is designed logically – also common sensealso common sense


START OF BLOCKSTART OF BLOCK

M03 – Spindle rotation normalM03 – Spindle rotation normal

M04 – Spindle rotation reverseM04 – Spindle rotation reverse

M06 – ATCM06 – ATC

M07 – Coolant mistM07 – Coolant mist

M08 – Coolant ONM08 – Coolant ON


END OF BLOCKEND OF BLOCK

M00 Compulsory program stopM00 Compulsory program stop

M01 Optional StopM01 Optional Stop

M02 End of programM02 End of program

M05 Spindle stopM05 Spindle stop

M09 Coolant OFFM09 Coolant OFF

M30 Program endM30 Program end

M60 APC M60 APC


MACHINE FUNCTIONMACHINE FUNCTION

Coolant Function: M07, M08, M09Coolant Function: M07, M08, M09

Spindle Function: M03, M04, M05Spindle Function: M03, M04, M05

Gear range Selection: M41, M42, M43, Gear range Selection: M41, M42, M43, M44M44

Machine Accessories: M06, M60, Machine Accessories: M06, M60, M23.m24, M98, M99M23.m24, M98, M99


THANK YOUTHANK YOU

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DMFD 3333 – CNC TECHNOLOGY