cam lab manual expereiment_10-13_cam

8/19/2019 CAM Lab Manual Expereiment_10-13_CAM

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Experiment 10

CNC Post Processor

A Post Processor is a unique “driver” specific to a CNC machine; some CNC machines start at differentlocations or require extra movement between each operation, the Post-Processor wors with the CA!

software to mae sure the "-Code output is correct for a specific machine build# Another example of use

for a Post-Processor would be an A$C %Automatic-$ool-Chan&e' for a CNC, the Post-Processor is

required so the correct $ool is collected from the correct location# $he Post Processor controls the format

and s(ntax of the pro&ram that is &enerated for the controller that controls a specific machine %t(picall( a

CNC or a robot'#)*+

A post processor is commonl( used b( the CA! %Computer Aided !anufacturin&' oftware to

&enerate "-code for a specific CNC !achine#

NC machines wor b( followin& the commands or instructions %"-codes !-codes' which are &iven in

Part Pro&ram# .ere are "-codes for !AC./ CNC control which are necessar( for a CNC machinists to

learn to understand CNC pro&rammin

G code Description

G00 Rapid traverse

G01 Linear interpolation

G02 Circular interpolation CW

G03 Circular interpolation CCW

G04 Dwell

G09 Exact stop

G10 Prora!!a"le data input

G20 #nput in inc$

G21 #nput in !!

G22 %tored stro&e c$ec& 'unction on

G23 %tored stro&e c$ec& 'unction o(

G2) Re'erence position return c$ec&

G2* Return to re'erence position

G32 +$read cuttin

https://en.wikipedia.org/wiki/Post_processor#cite_note-1https://en.wikipedia.org/wiki/Post_processor#cite_note-1https://en.wikipedia.org/wiki/Post_processor#cite_note-1


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G40 +ool nose radius co!pensation cancel

G41 +ool nose radius co!pensation le't

G42 +ool nose radius co!pensation ri$t

G)0 ,inis$ !ac$inin c-cle

G)1 +urnin c-cle

G)2 ,acin c-cle

G)3 Pattern repeatin c-cle

G)4 Pec& drillin c-cle

G). Groovin c-cle

G)/ +$readin c-cle

G92 Coordinate s-ste! settin or !ax spindle speed settin

G94 ,eed Per inute

G9. ,eed Per Revolution

G9/ Constant sur'ace speed control

G9) Constant sur'ace speed control cancel

!-code are CNC pro&ram instructions which help CNC machinistpro&rammer to control CNC machine

hardware lie chuc, tailstoc, quill, coolant# .ere are listed !-code which are mostl( used on CNC

lathemill with !AC./ CNC control#

M code Description

00 Prora! stop

01 ptional prora! stop

02 End o' prora!

03 %pindle start 'orward CW

04 %pindle start reverse CCW

0. %pindle stop

0* Coolant on

09 Coolant o(

29 Riid tap !ode

30 End o' prora! reset


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40 %pindle ear at !iddle

41 Low Gear %elect

42 i$ Gear %elect

/* -draulic c$uc& close

/9 -draulic c$uc& open

)* +ailstoc& advancin

)9 +ailstoc& reversin

94 irror i!ae cancel

9. irror i!ae o' axis

9* %u"prora! call

99 End o' su"prora!


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Experiment 11

Development of CNC code for Free Form

PARTNO / APT-1

CLPRNT

UNITS / MM

NOPOST

CUTTER / 10.0

$$ GEOMETRY DEFINITION

SETPT = POINT / 0.0, 0.0, 0.0

STRTPT = POINT / 70,70,0

P1 = POINT / 50, 50, 0

P2 = POINT / 20, -20, 0

C1 = CIRCLE / CENTER, P2, RADIUS, 30

P3 = POINT / -50, -50, 0

P5 = POINT / -30, 30, 0

C2 = CIRCLE / CENTER, P5, RADIUS, 20

P4 = POINT / 50, -20, 0

L1 = LINE / P1, P4

L2 = LINE / P3, PERPTO, L1

L3 = LINE / P3, PARLEL, L1

L4 = LINE / P1, PERPTO, L1

PLAN1 = PLANE / P1, P2, P3

PLAN2 = PLANE / PARLEL, PLAN1, SMALL, 1!

$$ MOTION COMMANDS

SPINDL / 3000, C"

FEDRAT / 100, 0

FROM / STRTPT

GO/TO, L1, TO, PLAN2, TO, L4

TLLFT, GOF"D / L1, TANTO, C1

GOF"D / C1, TANTO, L2

GOF"D / L2, PAST, L3

GORGT / L3, TANTO, C2

GOF"D / C2, TANTO, L4

GOF"D / L4, PAST, L1

NOPS


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GOTO / STRTPT


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Experiment 12

Turning Cycle for Straigt Turning

G20 longitudinal turning cycle for Fanuc 21 TB cnc control is a modal G-code.G20 turning cycle can

be used for straight turning and taper turning as well.G20 turning cycle is Easy to program and learn.

G20 turning cycle is used for simple turning however multiple passes are possible by specifying the

X-axis location of additional passes.

G20 +urnin C-cle ,or!at 'or %trai$t +urnin

G20 # 5# ,6

G20 U# "# ,6

X – Diameter to be cut (absolute).

Z – End point in z-axis (absolute).

F – Feed-rate.

U – Diameter to be cut (incremental).

W – End point in z-axis (incremental).

G9/ %200 03G00 ./0 520G20 .10 "-20.0 ,02.

4/04103/0310


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300G00 100 510030

CNC !rogram Code Explanation

As you can see in the above cnc program code,

Tool is at X56 Z2 point,

First cut is made at X51 and tool travels W-20 in Z-axis.

Second cut is made at X46

Third cut is made at X41

…

Last cut is made at X30

G20 +urnin C-cle ,unction

As if you study the above cnc program code you will notice that,

1 – with G20 both absolute (X51.0) and incremental (W-20.0) values are used to make cuts.

2 – If above code also shows a very powerful functionality of G20 turning cycle which is that a cnc machinist

can control depth-of-cut of every pass of G20 turning cycle which is impossible to achieve with other Turning

Canned Cycle like G71 Rough Turning Cycle.

So you will notice first five-cuts are of 5mm deep but the last one is just 1mm deep.

Cancellation o' G20 +urnin C-cle

G20 turning cycle is a modal G-code.“Modal” G-code meaning that they stay in effect until they are cancelled or replaced by a contradictory G code.

It means G20 turning cycle remains active until another motion command is given like G00, G01 etc. As in

above cnc program example G20 G code is cancelled with G00 G code.


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Experiment 1"

SN#! G#$GE

A0!1 $o measure the unnown components of fixed dimensions and to sort out the defected one#

APPA2A$31 nap &au&e, 4loc "au&es# $.56271 nap &au&e is a form of "ono &o &au&e# 0t is a

limit &a&e with permanentl( or temporaril( fixed measurement aperture%s' %&aps' which is used to quicl(

verif( whether an outside dimension of a part matches a preset dimension or falls within predefined

tolerances

,iure7 %nap Gaue

%&servation Ta&le

% 8 ccepted %a!ple Re:ected %a!ple1234.


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Result7

1; +$e nu!"er o' speci!en accepted < ==================

2; +$e nu!"er o' speci!en re:ected < ========

Plu aue is an external !easurin sur'ace> desined to c$ec& t$e contour or

si?e o' an openin

PRCED@RE7

1 +o c$ec& w$et$er t$e $ole drilled is o' t$e dia!eter o' t$e co!ponent

2 predeAned snap aue o' si?e o' t$e $ole is ta&en

3 #' t$e snap aue Ats into t$e $ole> it is called Go Gaue and t$e co!ponent is

accepted

4 #' t$e %nap aue does not At into t$e $ole> it is called 8o Go aue and t$e

co!ponent is re:ected

,iure7 Plu Gaue

B%ER+#8 8D +B@L+#8

% 8 ccepted %a!ple Re:ected %a!ple1234.

RE%@L+7

1; +$e nu!"er o' speci!en accepted < ==================

2; +$e nu!"er o' speci!en re:ected < ===================

cam lab manual expereiment_10-13_cam

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