12064 COMPUTER AIDED DESIGN AND MANUFACTURING PRACTICAL Predetermined 3D Objects (OR) 3D Solid Premitives BOX WEDGE CONE SPHERE CYLINDER TORUS Converting 2D Plan into a 3D Model Draw the 2D Object using polyline command after using extrude , revolve commands and applying Boolean operation such as union, subtract, intersect
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12064
COMPUTER AIDED DESIGN AND MANUFACTURING PRACTICAL
Predetermined 3D Objects (OR) 3D Solid Premitives
BOX WEDGE CONE
SPHERE
CYLINDER TORUS
Converting 2D Plan into a 3D Model
Draw the 2D Object using polyline command after using extrude , revolve commands and applying Boolean operation such as union, subtract, intersect
commands.3DMesh
Draw menu: Modeling » Meshes » 3D mesh
Command entry: 3dmesh
Enter size of mesh in M direction: Enter a value between 2 and 256
Enter size of mesh in N direction: Enter a value between 2 and 256
3DFace
Draw menu: Modeling » Meshes » 3D Face
Command entry: 3dface
Specify first point or [Invisible]: Specify a point (1) or enter i
3D Poly
Draw menu: 3D Polyline
Command entry: 3dpoly
Specify start point of polyline: Specify a point (1)
Specify endpoint of line or [Undo]: Specify a point or enter an option
Specify endpoint of line or [Undo]: Specify a point or enter an option
Specify endpoint of line or [Close/Undo]: Specify a point or enter an option
Creating surfaces
Modeling » Meshes » Ruled Mesh
Command: rulesurf
Current wire frame density : SURFTAB1=current
Select first defining curve:
Select defining curve:
Modeling » Meshes » Revolved Mesh
Command: revsurf
Current wire frame density:SURFTAB1=current:SURFTAB2=current
Select object to revolve: select a line,arc,circle,or 2D or 3D POLYLINE
Select object that defines axis of revolution: select a line or open 2D or 3D polyline.
Draw menu: modelling » Meshes » Tabulated Mes
Command: tabsurf
Select object for path curve
Select object for direction vector: select a line or open polyline
Draw menu: Modeling » Meshes » Edge Mesh
Command: edgesurf
Current wire frame density: SURFTAB1=current SURFTAB2=current
Select object 1 for surface edge:
Select object 2 for surface edge:
Select object 3 for surface edge:
Select object 4 for surface edge:
3D VIEW
View>3dview1. SW- South West.
2. SE-South East.
3. NE-North East.
4. NW-North West.
View ports
Viewports are areas that display different views of your model. As you work on the Model tab, you can split the drawing area into one or more adjacent rectangular views known as model space viewports.
View menu : 3D Views » Viewpoint
Command: vpoint
Specify a view menu or [Rotate] <display compass and tripod>: Specify a point, enter r, or
press ENTER to display a compass and axis tripod
Using the X,Y,Z coordinate you enter, creates a vector that defines a direction from which the
drawing can be viewed. The view defined is as if the viewer is looking from the point back at
the origin (0,0,0).
Hide
View menu: Hide
Command entry: hide
DView
Command entry: dview
Select object:
Model space
Command : mspace
Commands operate in either model space or paper space. You use model space
(the Model tab) to do drafting and design work and to create two-dimensional
drawings or three-dimensional models.
Paper space
Command model
On the Model tab, you can create drawings in model space.
Region
Regions are two-dimensional areas you create from closed shapes or loops. Closed polylines,
lines, and curves are valid selections. Curves include circular arcs, circles, elliptical arcs,
ellipses, and splines.
Draw menu: Region
Command entry: region
Select objects: Use an object selection method and press ENTER .
Pedit
It is used to convert 2D Multiple entity to 2D Single entity.
Command entry: pedit
Select polyline or [Multiple]: Use an object selection method or enter m
Extrude
Draw menu: Modeling » Extrude
Command entry: extrude
Select objects to extrude:
Specify height of extrusion or [Direction/Path/Taper angle] <default>: Specify a distance or enter p
Draw menu: Modeling » Revolve
command: revolve
dash board: 3D Make panel, Revolve
current wire frame density: ISOLINE=4
select object to revolve: use an object selection method
Union
Modify menu: Solid Editing » Union
command:: union
select objects: use an object selection method and press ENTER when you finish selecting
objects
SubtractModify menu: Solid Editing » Subtract
command: subtract
Select solids and regions to subtract from...
Select objects: Use an object selection method and press ENTER when you finish
Select solids and regions to subtract...
Select objects: Use an object selection method and press ENTER when you finish
Align
Modify menu: 3D Operations » Align
Command : align
Select objects: Select the objects to align and press ENTER
Specify either one, two, or three pairs of source points and definition points to align the selected objects. ALIGN Using One Pair of Points
Specify first source point: Specify a point (1)
Specify first destination point: Specify a point (2)
Specify second source point: Press ENTER
Fillet
Modify menu: Fillet
Command entry: fillet Current settings: Mode = current, Radius = current
Select first object or [Undo/Polyline/Radius/Trim/Multiple]: Use an object selection
method or enter an option
Chamfer
Modify menu: Chamfer
Command entry: chamfer
(TRIM mode) Current chamfer Dist1 = current, Dist2 = current
Select first line or [Undo/Polyline/Distance/Angle/Trim/mEthod/Multiple]: Use an object selection method or enter an option.
3D Array
Modify menu: 3D Operations » 3D Array
Command entry: 3darray
Select objects: Use an object selection method
Enter type of array [Rectangular/Polar] <R>: Enter an option or press ENTER
3D Mirror
Command entry: mirror3d
Grip tools available through the 3DMOVE and 3DROTATE commands to manipulate 3D
objects. For more information about using grip tools,
Select objects: Use an object selection method and press ENTER to finish
Specify first point of mirror plane (3 points) or [Object/Last/Zaxis/View/XY/YZ/ZX/3points]
<3points>: Enter an option, specify a point, or press ENTER
Rotate 3D
Command entry: rotate3d
It is recommended that you use the grip tools available through the 3DMOVE and
3DROTATE commands to manipulate 3D objects. For more information about using grip tools,.
Select objects: Use an object selection method and press ENTER when you finish
Specify first point on axis or define axis by [Object/Last/View/Xaxis/Yaxis/Zaxis/2points]:
Specify a point, enter an option, or press ENTER
WORKING WITH UCS
The user coordinate system provides a movable coordinate system for coordinate entry, plans of cooperation, and viewing. Most AutoCAD geometric editing commands and dependent on the location and orientation of the UCS; objects are drawn on the XY Plane of the current UCS.
Command: ucs
Specify origin of new UCS or [zxis/3points/object/face/view/x/y/z]:
3D COORDINATE SYSTEM
DDUCS
PLAN
UCSICON
Command : ucsicon
ON/OFF/ALL/No origin/Origin<current>:
Developing LISP program
To develop an AutoLISP program with VLISP perform the following steps:
1. Design the program .2. Write the code.3. Format the code for readability.4. Check for the error in the program.5. Test and debug the program.
Constructing a list
Car
Returns the first element of a list(car list)Command: (car '(a b c))ACommand: (car '((a b) c))(A B)
Cdr
Returns a list containing all but the first element of the specified list(cdr list)Command: (cdr '(a b c))(B C)Command: (cdr '((a b) c))(C)
Caar, cadr, caddr, cddr, cdar
AutoLISP supports concatenations of CAR and CDR.
(setq x ‘((ab) cd ))
Then (caar x ) is equivalent to (car x) returning A(cdar x) is equivalent to (cdr(car x)) returning (B)(cadar x) is equivalent to (car(cdr(car x))) returning B(cadr x) is equivalent to (car(cdr x)) returning (C)(cddr x) is equivalent to (cdr(cdr x)) returning (D)(caddr x) is equivalent to (car(cdr(cdr x))) returning D
Member
Searches a list for an occurrence of an expression and returns the remainder of the list, starting with the first occurrence of the expression
(member expr lst)
Command: (member 'c '(a b c d e))(C D E)
Length
Returns an integer indicating the number of elements in a list
(length lst)
Command: (length '(a b c d))4 Command: (length '(a b (c d)))3
List
Takes any number of expressions and combines them into one list.
(list expr….)
(list ‘a’(bc)’d) returns (A B C)
Polar
Returns the UCS 3D point at a specified angle and distance from a point
(polar pt ang dist)
pt
A 2D or 3D point.
ang
An angle expressed in radians relative to the world X axis. Angles increase in the counterclockwise direction, independent of the current construction plane.
dist
Distance from the specified pt.
Command: (polar '(1 1 3.5) 0.785398 1.414214)
(2.0 2.0 3.5)
Input/output Functions
User
Function Description
(entsel [msg]) Prompts the user to select a single object (entity) by specifying a point
(getangle [pt] [msg])
Pauses for user input of an angle, and returns that angle in radians
(getangle pt [msg]) Pauses for user input of a rectangle's second corner
(getdist [pt] [msg]) Pauses for user input of a distance
(getfiled title default ext flags)
Prompts the user for a file name with the standard AutoCAD file dialog box, and returns that file name
(getint [msg]) Pauses for user input of an integer, and returns that integer
(getkword [msg]) Pauses for user input of a keyword, and returns that keyword
(getorient [pt] [msg])
Pauses for user input of an angle, and returns that angle in radians
(getpoint [pt] [msg])
Pauses for user input of a point, and returns that point
(getreal [msg]) Pauses for user input of a real number, and returns that real number
(getstring [cr] [msg])
Pauses for user input of a string, and returns that string
(initget [bits] [string])
Establishes keywords for use by the next user input function call
(nentsel [msg])Prompts the user to select an object (entity) by specifying a point, and provides access to the definition data contained within a complex object
(nentselp [msg] [pt])
Provides similar functionality to that of the nentsel function without the need for user input
Display control functionsFunction Description
(graphscr) Displays the AutoCAD graphics screen(grdraw from to color [highlight])
Draws a vector between two points, in the current viewport
(grtext [box text [highlight]])
Writes text to the status line or to screen menu areas
(grvecs vlist [trans]) Draws multiple vectors on the graphics screen(menucmd string) Issues menu commands, or sets and retrieves menu item status
(setq l (getreal "Enter the Length of rectangle:")
b (getreal "Enter the Breath of rectangle:")
sp (getpoint "Enter the starting point:")
);setq
(setq p2 (polar sp 0 l))
(setq p3 (polar p2 (/ pi 2) b))
(setq p4 (polar p3 pi l))
(command "pline" sp p2 p3 p4 "c")
)
output
Enter the Length of rectangle:50.0
Enter the Breath of rectangle:25.0
Enter the starting point:
CIRCLELISP PROGRAM
(defun c:cir()
(setq p1 (getpoint "Enter the center point:")
cen (getreal "Enter the radius of the circle:")
);setq
(command "circle" p1 cen )
)
output
Enter the center point:
Enter the radius of the circle:12.0
CONCENTRIC CIRCLES
LISP PROGRAM
(defun c:concir()
(setq n (getint "Enter the number of circles:")
rad (getreal "Enter the radius of the circle:")
cp (getpoint "Enter the center point:")
i (getreal "Enter the increment in radius:")
);setq
(repeat n
(command "circle" cp rad)
(setq rad (+ rad i))
);repeat
);defun
output
Enter the number of circle: 20
Enter the radius of the circle: 15.0
Enter the increment in radius: 2.0
CHANGE COLORS AND LINE TYPES
LISP PROGRAM
(defun c:concir()
(setq n (getint "Enter the number of circles:")
rad (getreal "Enter the radius of the circle:")
cp (getpoint "Enter the center point:")
i (getreal "Enter the increment in radius:")
);setq
(repeat n
(command "circle" cp rad)
(command "linetype" "set" "dashed" "")
(command "color" "1")
(setq rad (+ rad i))
);repeat
);defun
GENEVA GEAR MECHANISM
Aim:
To draw the given 3D solid Geneva gear mechanism as per the dimensions and calculate the mass properties.
System Requirements
1. Personal computer (Pentium processor)2. MS Windows OS (Version 2000 or above)3. AutoCAD software (release 2000 or above)4. Laser jet printer for getting hard copies of student work
Commands:
1. Limits
2. Zoom
3. Pline
4. Offset
5. Arc
6. Pedit
7. Array
8. Extrude
9. Subtract
10. Trim
11. Massprop
Result
Thus the given 3D solid Geneva gear mechanism are drowned and mass properties are calculated.
GENEVA GEAR MECHANISM
ALL DIMENSIONS ARE IN INCH
CAST IRON BLOCK
ALL DIMENSIONS ARE IN mm
BEARING BLOCK
ALL DIMENSIONS ARE IN mm
STRAP JOINT WITH GIB AND COTTER
UNIVERSAL COUPLING
BUSHED BEARING
SCREW JACK
PART-II
CAM PRACTICAL
Numerical control system
Controlling the movement of the various slides of a machine tool with the help of numbers,Letters and symbols is known as Numerical control system.
Computer Numerical Control System The use of a dedicated computer, to perform the Basic numerical control functions is known as computer numerical control system.
CNC Turning Centre CNC Lathes, are more appropriately called as Turning Centre. The turning centre for producing components of cylindrical shapes.
Multiple spindle turning centre CNC Machining Centre
The CNC Milling machines are called as machining centre or manufacturing centre. It is a multifunctional machine tool. It is a single piece of automated production equipment. Which is capable of performing different operations like milling, drilling, boring, reaming, counter boring ,etc.
Part program
Part means component. Program means sequence of steps. Therefore the sequence of steps involved in producing components in a CNC Machine is known as part program.
Method of creating part program
Manual part programmingComputer assisted part programmingAPT ProgrammingConversional programmingGraphical programmingVerbal programming
NC Related dimensioningAbsolute programmingIncremental programming
Structure of a CNC part program
N G X Y Z F S T M
N - Block Number
G - Preparatory code function
X Y Z - Co ordinate values
F - Feed
S - Spindle speed
T - Tool function
M - Miscellaneous code function
Part program format
Fixed sequential formatTAB sequential formatWord address format
Interpolation
In CNC Machines, either the tool or the work slide move relative to each other. This movementof tool or the work slide may be straight line, circular arc, etc
Canned cycle
Canned cycle is employed for stock removal in multiple passes. This type of cycle is called as Fixed cycle. Canned cycle employed for
G00-Rapid positionG01-Linear interpolationG02-Circular interpolation (CW)G03-Circular interpolation(CCW)G20- Inch data inputG21- Metric data inputG28- Reference point returnG40- Tool nose radius compensation cancelG50- Maximum spindle speed settingG70- Finishing cycleG71- stock removal in turningG72- stock removal in facingG74- peck drilling in z-axisG75- Multiple grooving cycleG76- Multiple thread cutting cycleG98- Feed per minute
MISCELLANEOUS FUNCTION (M CODE)
M03- Spindle rotation (cw)M05- Spindle stopM06- Tool changeM08- Coolant ONM09- Coolant OFFM70- X-axis mirror ONM71- Y-axis mirror ONM80-X-axis mirror OFFM81-Y-axis mirror OFFM98- Sub program callM99- Sub program exit
SYNTAX FOR TURNING CENTRE (LATHE )
FAST TRAVERSE-G00
G00 X Z G00 => Fast TraverseX , Z => Co-ordinate values
LINEAR MOTION-G01
G01 X ZG01 => Linear motionX , Z => Co-ordinate values
REFERENCE POINT-G28
G28 U0 W0G28 => Reference pointU , W => Machine Reference Point
CIRCULAR INTERPOLATION-G02/G03
G02 X Z R FG03 X Z R FG02 => Clockwise circular interpolationG03 => Counter clockwise interpolationX , Z => Co-ordinate valuesR => Radius of the CW /CCW ARC
SINGLE TURNING CYCLE-G90
G90 X Z FG90 => Single Turning CycleX , Z => Co-ordinate valuesF => Feed /minute
TAPER TURNING CYCLE-G90
G90 X Z R FG90 => Taper Turning CycleX , Z => Co-ordinate valuesR => The difference in incremental of the cut start radius value and the cut finish Radius value
F => Feed /minute
MULTIPLE TURNING-G71G71 U RG71 P Q U W FG71 => Multiple TurningU => Depth of cutR => Relief amountP => Start blockQ => End blockU => Finishing allowance in the X axisW => Finishing allowance in the Z axisF => Feed /minute
FINISHING CYCLE-G70
G70 P Q FG70 => Finishing CycleP => Start blockQ => End blockF => Feed /minute
PECK DRILLING CYCLE-G74
G74 RG74 X Z Q FG74 => Peck drilling cycleR => Relief amountX , Z => Co-ordinate valuesQ => Depth of cut in each pass ( microns)F => Feed/minute
GROOVING CYCLE-G75G75 R
G75 X Z P Q F
G75 => Grooving Cycle
R => Return amount
X , Z => Co-ordinate values
P => Peck increment in X-axis (microns)
Q => Stepping distance in Z-axis (microns)
F => Feed /minute
MULTIPLE THREADING CYCLE-G76
G76 P(m)(r)(a) Q(q1) R
G76 X Z P Q(q2) F
m => Repetitive count in finishing
r => Pull out angle
a => Angle of tool tip
q1 => Minimum cutting depth
R => Finishing allowance
X , Z => Co-ordinate values
P => Height of the thread as a radius value x 1000
q2 => Depth of the first cut as a radius value x 1000
F => Lead or Pitch of the thread
SYNTAX FOR MACHINING CENTRE (MILLING )
FAST TRAVERSE-G00
G00 X Y Z G00 => Fast TraverseX , Y , Z => Co-ordinate values
LINEAR MOTION-G01
G01 X Y ZG01 => Linear motionX , Y , Z => Co-ordinate values
REFERENCE POINT-G28
G28 X0 Y0 Z0G28 => Reference pointX , Y , Z => Machine Reference Point
CIRCULAR INTERPOLATION-G02/G03
G02 X Y R F
G03 X Y R FG02 => Clockwise circular interpolationG03 => Counter clockwise interpolationX , Y => Co-ordinate valuesR => Radius of the CW /CCW ARC
FAST PECK DRILLING CYCLE-G73
G73 X Y Z P Q R FG73 => Peck drilling cycleX , Y , Z => Co-ordinate valuesP => Dwell time in secQ => Depth of cut for each peck drill always a positive incremental valueR => Z coordinate of the R pointF => Feed/minute
CIRCULAR POCKETING –G170-G171
G170 R(r1) P(p1) Q(q1) X(x1) Y(y1) Z(z1) I(i1) J(j1) K(k1)G171 P(p2) S(s2) R(r2) F(f2) B(b2) J(j2)G170 => Roughing cycler1 => Position of tool to start cycle for flat surface r1 = 0p1 => 0 for roughing, => 1 for finishingq1 => Peck increment for each cut ( + value)x1,y1,z1 => co-ordinate valuesi1 => Finishing allowance for sidej1 => Finishing allowance for pocket basek1 => Radius of circular pocket as CW ARC ( + value)G171 => Finishing cyclep2 => Cutter movement percentages2 => Roughing spindle speedr2 => Roughing feed in Z directionb2 => Finish spindle speedj2 => Finishing feed, mm/min
RECTANGULAR POCKETING –G172-G173
G172 I(i1) J(j1) K(k1) P(p1) Q(q1) R(r1) X(x1) Y(y1) Z(z1) G173 I(i2) K(k2) P(p2) T(t2) S(s2) R(r2) F(f2) B(b2) J(j2) Z(z2)G172 => Roughing cyclei1 => Length of the pocket in X- directionj1 => Length of the pocket in Y- directionk1 => Corner radiusp1 => 0(roughing), =1(Finishing)q1 => depth of cut for each passr1 => Absolute depth from surfacex1 => Pocket corner Xy1 => Pocket corner Yz1 => Absolute Z base of pocketG173 => Finishing cyclei2 => Pocket side finishing allowancek2 => Pocket side finishing allowancep2 => Cutter width percentaget2 => Tool number Finishs2 => Spindle speed, rpmr2 => Roughing feed in Z mm/minf2 => Roughing feed along XYb2 => Finishing spindle speed, rpmj2 => Finishing feed, mm/minz2 => safety Z position
AIM Write a manual part program for -------------------------------------------------------------- for the components as shown in DWG.
SYSTEM REQUIREMENTS
1. Personal computer (Pentium processor)2. MS Windows OS (Version 2000 or above)3. AutoCAD software (release 2000 or above)4. CNC Lathe and Milling simulation software5. Laser jet printer for getting hard copies of student work
PROCEDURE
1. Select control type from main menu and pick the Fanuc_ mill or Fanuc_turn.
2. File New Cnc Program
3. Job/Tooling Fill the correct data for Billet setting, Tool Offsets and Select Tooling.
4. Enter the Cnc Part Program in the CNC Editor.
5. File save as (save the cnc part program)
6. Select Cycle start from Control panel.
7. Simulation is done.
RESULT
Thus the CNC Part Program was simulated successfully.
STEP TURNING
ALL DIMENSIONS ARE IN mm
BILLET SETTING
1. Select Metric Programming.2. Billet length = 453. Billet Diameter = 254. Billet X shift = 05. Billet Z shift = 06. X axis shift = 07. Z axis shift = 0