UNIT 7 - CNC - Lecture 3 - Programming

8/16/2019 UNIT 7 - CNC - Lecture 3 - Programming

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CNC Programming

Automated Programming Tool – APT Language

Preparation of CNC programs and provingthem is rst step to machine the part.

CNC programs are also called part programs.

There are two types of codes are used in CNCprogramming:

preparatory codes (G Codes ! G" Codes

miscellaneous codes (# codes


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CNC Programming

Proving a Part Program

• Study the part

• Identify the machine

tool(s)

• Identify operations and

tooling

• etermine process

parameters

• evelop part program

• Simulate tool path

• ry run

• Cut single part


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CNC Programming


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!otion Statements

"## Linear !ovement (rapid)

"#$ Linear !ovement (feed)"#% Circular !ovement (c& feed)

"#' Circular !ovement (cc& feed)

CNC Programming


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"## Linear !ovement (rapid)

(# #)

$# %

*

+

,#

--"## *-- +,#

CNC Programming


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.*

./

Tool at (%- '-)

"## *# /'-

"## *# /#

CNC Programming


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Initial iameter 0 $#

mm1inal iameter 0 , mmepth of cut 0 $ mm2idth of cut 0 3 mm

G00 X4 Z1

G01 Z-8

G00 X5 Z1

G00 X 3

G01 Z-8

G00 X4 Z1

CNC Programming


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*

+

(# --)

%#

'-

%3

'#

$3

-3

'

"#$ *'# +--"#$ *'# +%#

"#$ *3 +%#"#$ *3 +#"#$ *$#, +#"#$ *$#, +%3"#$ *4% +%3

"#$ *'#"#$ +%#

"#$ *3"#$ +#"#$ *$#,"#$ +%3"#$ *4%

"5$"#$ *'#"#$ +6'-

"#$ *$3"#$ +6%#"#$ *-3"#$ +%3"#$ *6'

CNC Programming


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Preparatory NC Codes

"## Linear !ovement (rapid)"#$ Linear !ovement (feed)

"#% Circular !ovement (c&)

"#' Circular !ovement (cc&)

"4# Inch units

"4$ !etric units

"5 1eed in mm7min

"5- 1eed in mm7rev

"5, Speed in mm7min

"54 Speed in 8P!

"5# A9solute dimensions

"5$ incremental dimensions

CNC Programming

"$4 *+ Plane"$3 /* Plane"$5 +/ Plane


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"#% Circular !ovement (Cloc:&ise)

(# #)

$#

%

*

+

G02 X34 Y0 I0 J-24

G02 X34 Y0 R24

CNC Programming


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"#% Circular !ovement (Cloc:&ise)

CNC Programming

1ull Circles &ith I;<or 8=


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!iscellaneous NC Codes

!#% >nd of program

!#' Cloc:&ise rotation of spindle

!# Counter6cloc:&ise rotation of spindle

!#- Stop rotation of main spindle

!#, Tool change

!#4 Coolant on

!#5 Coolant o?

CNC Programming


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N##$# "5#N##$$ "#$ *$ +%N##$% "#$ *% +%N##$' "5$N##$ "#$ *$

N##$- "#$ *$ +$

(##)

($%)

(%%) ('%)

(')

CNC Programming


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CNC Programming

3#

$##

#

%#

,#

3#

-#

'#

$-

(## -##-#)"## Linear !ovement (rapid)

"#$ Linear !ovement (feed)

"#% Circular !ovement (c&)"#' Circular !ovement

(cc&)

"4# Inch units

"4$ !etric units

"5 1eed in mm7min

"5- 1eed in mm7rev

"5, Speed in mm7min

"54 Speed in 8P!

"5# A9solute dimensions

"5$ incremental dimensions"$4 *+ Plane"$3 /* Plane"$5 +/ Plane

!#% >nd of program

!#' Cloc:&ise rotation ofspindle

!# Counter6cloc:&iserotation of spindle

!#- Stop rotation of main

spindle!#, Tool change

All dimensions in mmepth of hole 0 mm

@ole iameter 0 - mm


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N$# "4$ "5# "5 "54 !#' !#4 S-##

N%# "#$ *5# +$# 1%##

N'# "#% *5# +$# 8%#

N# "## *$## +$#

N-# "## *3# +#N,# "5$

N4# "#$ *5# +$%#

N3# "#' *# +# 8$-

N5# "## *%# +%#N$## !#- !#5

N$$# !#%

CNC Programming

2hy N$# N%# N'# not N$$N$% N$' etc=


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-## '$

,# -# ,#

epth of cut 0 ' mm

CNC Programming


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CNC ProgrammingCutter 8adius Compensation

Part

proBle

Tool Path


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"% – Cutter 8adius compensation 8ight

Cutting tool is on the 8I"@T side of the part in thedirection of movement


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"$ – Cutter 8adius compensation Left

Cutting tool is on the L>1T side of the part in the directionof movement


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"% – Cutter 8adius compensation 8ightCutting tool is on the 8I"@T side of the part in thedirection of movement

"$ – Cutter 8adius compensation LeftCutting tool is on the L>1T side of the part in the directionof movement

"# – Cutter 8adius compensation CANC>L


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CNC Programming


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CNC Programming


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CNC Programming

!AL NN 6!AL

!odal code is e?ective untilcancelled 9y anothercommand

Non !odal code ise?ective only for asingle 9loc: or line ofcode

>DamplesE

"#"$"5$"4$

>DamplesE

"#$"#%"##

"#'


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CNC Programming!irror Images

$anuc Controller

!%# cancellation of mirroring image

!%$ !irror image on * aDis

!%% !irror image on + aDis

!%' !irror image on / aDis

#A%" Controller

"4' *6$ !irror image on * aDis

"4' *$ !irror image on * aDiscancel

"4' +6$ !irror image on + aDis

"4' +$ !irror image on + aDiscancel

"4' /6$ !irror image on / aDis

"4' /$ !irror image on / aDiscancel

i


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!%$ !irror image on * aDis

*

+

All * values areNegated

(--)

(%#-)

(-$#)

(%#$#)

(6--)

(6%#-)

(6-$#)

(6%#$#)

CNC P i


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!%% !irror image on + aDis

*

+

All + values areNegated

(--)

(%#-)

(-$#)

(%#$#)

%#6$#)(-6$#)

(%#6

-)

(-6-)

CNC P i


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CNC Programming8epetitions

"%- N66

"%- N66 L66

N$# "4$ "5# "5 "54 !#' !#4S-##

N%# "#$ *5# +$# 1%##N'# "#% *5# +$# 8%#N# "## *$## +$#N-# "## *3# +#N,# "%- N%#F-#N4# "5$N3# "%- L% N%#F-#N5# !#% !$4

CNC P i


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CNC ProgrammingSu9routines

P###$N- "5# "4$ "$4N$# "# *%# +%#N$- /-N%# PPP%#N %- "# *,# +%#N'# PPP %#N'- "# *,# +,#

N# PPP%#N- "# *%# +,#N-# PPP%#N-- "# /$##

N,# !#%

PPP%#N- "5$N$# "$ /6% 1%##

N$- *%#N%# +%#N%- *6%#N'# +6%#N'- /-N# "5#

A S>T 1 C>S 2IT@ A I11>8>NT NA!> 28ITT>N AT T@> >N 1 T@> !AIN C>

CNC P i


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CNC P i


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CNC ProgrammingCanned Cycles

!otion repeated a num9er of times

Common motions irrespective of the position of thetool

>DampleE rilling

Position the drill 9it at the center of the hole and alittle a9ove the surface – 8apid movement

!ove to the reGuired depth in feed motion

8eturn to the starting position

CNC P i


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"3$ – rilling"3% – Counter sin:ing"3% – eep @ole drilling"3 – Tapping

"3-3,343335 – Horing

L5- – 8ough TurningL54 – Thread Cutting

CNC P i


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"3$ 6 rilling Cycle

"3$ * + / 8

* + – (Dy) position of the center of the hole/ 6 The depth up to &hich the hole is to 9edrilled8 – Position of the clearance plane (. aDis)

8

/

CNC P i


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CNC Programming"3$ 6 rilling

Cycles

%-

'-

#

3#

3#

-#N$# "3$ *'- +%- /6$# 8-1$##

N%# * -# + 3#

N'# *3# +#

N# "3# *# +# /$#

"3# – Cancel rillingcycle

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UNIT 7 - CNC - Lecture 3 - Programming