1. MULTIAXIS TOOL PATH GENERATION OF CRANK SHAFT
ABOUT RAMTECH MANUFACTURING INDUSTRIES
Today’s developments of technology in the field of manufacturing sector and the
complexity of the aerospace components demanded the new methodologies in the production
practices and management of the production activities. Global business drivers such as
competition, consumer’s desires, and government regulations continue to influence the
manufacturing applications for product and process development, which leads to reduction in
cost and improvement in quality and productivity by reducing scrap and effective utilization of
man and machines.
At Ramtech Mfg. Industries, components are realized from the conceptual design
to computer aided design (CAD) of the component and then the CAD model of the component is
imported in CAM module and the tool path is generated for the component through simulation
and the generated NC program is fed to 5 axis and 3 axis CNC machines to manufacture the
component with high accuracy and surface finish thus covering the entire Product life cycle.
This project outlines, the generation of NC part program (manually or CAM) and
how the CAD tools are used in the study of product drawings and generation of 3D models using
UG-NX7.5 package. Computer aided design and manufacturing is a technology and application
driven field by utilization of which in industrial environment helps to close the gap between
creating the technology and using it. The work involved in the development of modeling of
components, which are going to be produced using the Part Modeling Module in the UG-NX7.5
software and development of post option files and machine configuration file for the machine
tool on which the component is going to be produced.
2. ABSTRACT
Process planning is a production organization activity that transforms a product design
into a set of instruction (sequence, machine tool setup etc.) to manufacture machined part
economically and competitively. The information provided in design includes dimensional
specification (geometric shape and its feature) and technical specification (tolerance, surface
finish etc.) The project aims for a detailed study about process planning to manufacture a
crankshaft for a 4 cylinder engine.
Modern power train is currently being faced with a variety of contradictions in terms of
emissions, fuel consumption, and noise as well as vibration level. This has forced to develop
concepts that assure high fuel economy, low exhaust emissions and high specific power that
enhance the mechanical performance of the engine through the development of light weight
engine parts.
The crankshaft, sometimes casually abbreviated to crank, is the part of an engine that
translates reciprocating linear piston motion into rotation. To convert the reciprocating motion
into rotation, the crankshaft has "crank throws" or "crankpins", additional bearing surfaces
whose axis is offset from that of the crank, to which the "big ends" of the connecting rods from
each cylinder attach.
The project aims for a detailed study about process planning to manufacture a crankshaft
for a 4 cylinder engine. Creating 3D model for crank shaft and generating multi axis tool path
and generating NC program for 5-axis DMG milling machine.
3. This process involves the following steps:
i. Development of 2D drawing
ii. Selection of suitable material with mating parts
iii. 3D model
iv. CAM process
Selection of raw material
Selection of machine
Selection of tool
Fixture design
Sequence of operations
Tool path generation
Process optimization
Post processor
INTRODUCTION
Process planning refers to the product design and decides how to manufacture it within
the resource constraints. Process planning can be seen as an activity which integrates knowledge
about products and resources.
Manufacturing process planning is the process of selecting and sequencing
manufacturing processes such that they achieve one or more goals and satisfy a set of domain
constraints.
4. Process planning is a production organization activity that transforms a product design
into a set of instruction (sequence, machine tool setup etc.) to manufacture machined part
economically and competitively. The information provided in design includes dimensional
specification (geometric shape and its feature) and technical specification (tolerance, surface
finish etc.)
My project deals with the manufacturing of “Crank Shaft” component using CAM
software (‘UGNX-7.5’ which is a CAD/CAM software used to generate part program by
designing and feeding the geometry of the component) and defining the proper tool path and
thus transferring the generated part program to the required CNC machine with the help of DNC
lines. Then the program is executed with suitable requirements.
The component can be either designed in UG or can be retrieved from any other CAD
software. Then sequence of programs such as modeling the component, selection of tools
according to the sequence of operations and sizes, generating the tool path, at last the generated
NC part program is verified and sent to the required CNC machine to manufacture the particular
component. Finally the required surface finish has been obtained by machining the component at
optimum speeds and feeds and the cost of machining is also optimized by choosing optimal
machining process and machine tools.
5. COMPUTER AIDED DESIGN
Computer-aided design (CAD), also known as computer-aided design and drafting (CADD),
is the use of computer systems to assist in the creation, modification, or optimization of a
design.
CAD may be used to design curves and figures in two-dimensional (2D) space or curves,
surfaces, and solids in three-dimensional (3D) space.
CAD is an important industrial art extensively used in many applications, including
automotive, shipbuilding, and aerospace industries.
CAD is one part of the whole Digital Product Development (DPD) activity within
the Product Lifecycle Management (PLM) processes, and as such is used together with other
tools, which are either integrated modules or stand-alone products.
Today’s industries cannot survive worldwide competition unless they introduce new
products with better quality, at lower cost, and with shorter lead time. Accordingly, they have
tried to use the computer’s huge memory capacity, fast processing speed, and user-friendly
interactive graphics capabilities to automate and tie together otherwise cumbersome and separate
engineering or production tasks, thus reducing the time and cost of product development and
production. Computer-aided design (CAD), computer-aided manufacturing (CAM), and
computer-aided engineering (CAE) are the technologies used for this purpose during the product
cycle. Thus, to understand the role of CAD, CAM, and CAE, we need to examine the various
activities and functions that must be accomplished in the design and manufacture of a product.
6. Computer-aided design (CAD) is the use of computer technology for the design of
objects, real or virtual. CAD often involves more than just shape. As in the manual drafting of
technical and engineering drawings, the output of CAD often must convey also symbolic
information such as materials, processes, dimensions, and tolerances, according to application-
specific conventions.
8. COMPUTER AIDED MANUFATURING
Computer-aided manufacturing (CAM) is the use of computer-based software tools that
assist engineers and machinists in manufacturing or prototyping product components and tooling.
CAM is a programming tool that makes it possible to manufacture physical models using
computer-aided programs.
Manufacturing as the design stage is a set of activities assigned to the producing of the
designed part. The manufacturing is one of other activities after design stage. The problem
consists in transformation of the CAD data to the manufacturing data. The manufacturing data
are sometimes called as CAM data.
The 10 largest CAM software products are:
Catia
Cimatron
Edgecam
Mastercam
NX
Powermill
Pro/E
Space-E/CAM
Tebis
9. WorkNC
Applications of CAD/CAM:
AutoCAD is a computer-aided drafting and design system implemenented on a personal
computer. It supports a large number of devices. Device drivers come with the system and
include most of the digitizers, printer/plotters, video display boards, and plotters available on the
market.
AutoCAD supports 2-D drafting and 3-D wire-frame models. The system is designed as a
single-user CAD package. The drawing elements are lines, polylines of any width, arcs, circles,
faces, and solids. There are many ways to define a drawing element. For example, a circle can be
defined by center and its radius, three points, and two end points of its diameter. The system
always prompts the user for all options.
Programming for NC, CNC, and industrial robots;
Design of dies and molds for casting, in which, for example, shrinkage allowances are
preprogrammed;
Design of tools and fixtures and EDM electrodes;
Quality control and inspection----for instance, coordinate-measuring machines
programmed on a CAD/CAM workstation;
Process planning and scheduling.
10. NUMERICAL CONTROL
The punched tape is the precise input medium used to control moving members of a
machine tool "automatically" as opposed to "manually". Organized numerical information
properly placed on an input medium, usually tape, functions as a series of sequenced machine
tool operating commands. The operating commands are executed automatically with amazing
speed, accuracy, efficiency, and repeatability.
When a command signal is given to the drive unit to perform the motion through certain
distance, the slide moves from the distance desired, which do not have a feedback device and
thus the actual position of the tool slide or worktable is not measured and verified. This system
depends upon the quality of the drive unit.
Open loop system is most often used on large machines that have already retrofitted. This
system offers cost savings for light duty, machinery where problems of instability are absent and
high precision is not required.
In closed loop system, program transmits to the control system, which tells where the tool
slide or table should be positioned. A feedback device transmits a signal back to the control
system including the true position, which creates an unbalanced condition. After the difference is
accurately measured by the electrical control system, the system transmits electrical signals to
the drive mechanism, causing the table tool slide to move in a direction tending to reduce this
difference.
11. COMPUTER NUMERICAL CONTROL
In CNC Machine tools, the part program punched on tape is run only once and then
stored in the Computer Memory. In recent CNC system the tape reader has been eliminated
altogether by incorporating Manual Data Input (MDI). In MDI consoles are elaborate
alphanumeric keyboards, which allow writing of fairly complex part programs directly into the
computer memory. In off line programming, the part program is written on a personal computer
using the appropriate programming software and is then loaded into the CNC system through a
data communication line.
CNC systems are widely used especially in the metal cut industry. The most common
applications are in milling, turning, drilling, boring, grinding and many other machining
operations. It is also effectively applied to press working, inspection machines, automatic
drafting, riveting, injection moldings etc, and even textile Industry.
Computer Numerical Control (CNC) is one in which the functions and motions of a
machine tool are controlled by means of a prepared program containing coded alphanumeric
data. CNC can control the motions of the work piece or tool, the input parameters such as feed,
depth of cut, speed, and the functions such as turning spindle on/off, turning coolant on/off.
The benefits of CNC are:
(1) High accuracy in manufacturing
(2) Short production time
(3) Greater manufacturing flexibility
(4) Simpler fixturing
(5) Contour machining (2 to 5 –axis machining)
(6) Reduced human error.
INTRODUCTION TO UNIGRAPHICS
12. NX, also known as NX Unigraphics or usually just U-G, is an advanced CAD/CAM/CAE
software package developed by Siemens PLM Software.
It is used, among other tasks, for:
Design (parametric and direct solid/surface modeling)
Engineering analysis (static, dynamic, electro-magnetic, thermal, using the Finite
Element Method, and fluid using the finite volume method).
Manufacturing finished design by using included machining modules
First release of the new "Next Generation" version of Unigraphics and I-deas, called NX.
This will eventually bring the functionality and capabilities of both Unigraphics and I-DEAS
together into a single consolidated product.
Increasing complexity of products, development processes and design teams is
challenging companies to find new tools and methods to deliver greater innovation and higher
quality at lower cost. Leading-edge technology from Siemens PLM software delivers greater
power for today’s design challenge. From innovative Synchronous Technology that unites
parametric and history-free modeling, to NX Active Mockup for multi-CAD assembly design,
NX delivers breakthrough technology that sets new standards for speed, performance, and ease
of use.
NX automates and simplifies design by leveraging the product and process knowledge
that companies gain from experience and from industry best practices. It includes tools that
designers can use to capture knowledge to automated repetitive tasks. The result is reduced cost
and cycle time and improved quality.
COMMONLY USED BASIC GD&T SYMBOLS
13. INPUT FOR THE PROJECT
2D Drawing
A 2D drawing is used to design a 3D model for our component using Unigraphics NX 7.5
CAD software.
14. Below shows the 2D drawings of the CRANK SHAFT with all the required dimensions
and GD&T representations the suits the best for manufacturing the component without any
errors.
Steps involved in 3d modeling
Sketching
Below is the sketch required to obtain the 3D model of the CRANK SHAFT from the
above 2D drawing.
Below image shows the sketch of the crank shaft
15. Procedure to draw the above sketch
Insert sketch in task environment select plane ok.
insert curve profile.
By using profile curve we will get the 2D design of crank shaft.
Below image shows the revolve option for the crank shaft.
16. Revolve
By using revolve command we convert sketch from 2D to 3D only for axis
symmetry bodies.
Insert design features revolve.
Select curve specify vector Boolean operation (none) ok.
17. Below image shows the sketch of the profile required.
Procedure to draw the above sketch
Insert sketch in task environment select plane ok.
insert curve profile.
18. Below image shows the extrude option .
EXTRUDE
Extrude command is used to create a body by sweeping a 2D or 3D section of curves,
Edges, sketches in a specified Direction.
Insert design features extrude.
Select curve specify vector Boolean operation (none) ok.
19. Below image shows the instance geometry option.
INSTANCE GEOMETRY
Copies Geometry into various pattern arrays
Here we use mirror
Insert associative copy INSTANCE GEOMETRY
Mirror select object specify plane ok.
20. Below image shows the instance geometry option.
INSTANCE GEOMETRY
Copies Geometry into various pattern arrays
Here we use translate.
Insert associative copy INSTANCE GEOMETRY
translate select object specify vector specify distance ok.
21. Below image shows the extrude option at one end of crank shaft.
EXTRUDE
Extrude command is used to create a body by sweeping a 2D or 3D section of curves,
Edges, sketches in a specified Direction.
22. Insert design features extrude.
Select curve specify vector Boolean operation (unite) ok.
Below image shows the hole option.
HOLE
23. Generate holes on the body by using Simple, Counter bore and Counter sunk.
insert design features hole.
In form & dimensions specify type of hole required (simple hole) and dimensions of hole (4dia,
15 depth). In Boolean select subtract option then click ok.
Below image shows the entire 3D component of the crank shaft.
24. MANUFACTURING PROCESS PLAN FOR CRANK SHAFT
CAM PROCESS
COMPUTER AIDED MANUFATURING
Computer-aided manufacturing (CAM) is the use of computer-based software tools
that assist engineers and machinists in manufacturing or prototyping product components and
tooling. CAM is a programming tool that makes it possible to manufacture physical models
using computer-aided programs.
Manufacturing as the design stage is a set of activities assigned to the producing of the
designed part. The manufacturing is one of other activities after design stage. The problem
consists in transformation of the CAD data to the manufacturing data. The manufacturing data
are sometimes called as CAM data.
The 10 largest CAM software products are:
Catia
Cimatron
Edge cam
Master cam
NX Cam
Power mill
Pro/E
Space-E/CAM
Tebis
WorkNC
SELECTION OF MACHINE
Number of different machines is used with an external controller and human or robotic operators
that move the component from machine to machine. In either case, the complex series of steps
25. needed to produce any part is highly automated and produces a part that closely matches the
original CAD design.
TYPES OF CNC MACHINES:
TYPES OF CNC MACHINE USED IN THIS PROJECT:
DMG 5-axis milling machine is used for manufacturing banjo fitting component. In DMG 5-axis
milling machine X, Y, Z, B, C are 5 vectors, X & Y are tool movement and Z is for table
upwards movement, B for spindle movement, C for table rotation.
High rigidity with Integrated Spindle up to 12000rpm, Spindle is directly coupled with
motor. Vertical Operations, Integrated rotary table of 1200mm X 700mm with rotary dia 700mm.
Horizontal Operations, With head tilting at 90deg.Angular and 5-axes simultaneous machining,
Capable of machining from +30 deg to -120deg head tilting. Machine accuracies, Positional
Accuracy +/- 0.005mm, Repeatability +/- 0.003mm
FOR CRANK SHAFT-axis milling machine is used
26. SELECTION OF TOOL
Selection of tools plays an important role in manufacturing any component. Proper tools must be
selected otherwise in manufacturing process improper tools results in damage of work piece or
damage to the tools, tool holders.
TOOL DESCRIPTION
END MILL
End mills (middle row in image) are those tools which have cutting teeth at one end, as well as
on the sides. The words end mill is generally used to refer to flat bottomed cutters, but also
include rounded cutters (referred to as ball nosed) and radiuses cutters (referred to as bull nose or
torus). They are usually made from high speed steel (HSS) or carbide, and have one or more
flutes. They are the most common tool used in a vertical mill.
FACE MILL
A face mill consists of a cutter body (with the appropriate machine taper) that is designed to hold
multiple disposable carbide or ceramic tips or inserts, often golden in color. The tips are not
designed to be re sharpened and are selected from a range of types that may be determined by
27. various criteria, some of which may be: tip shape, cutting action required, and material being cut.
When the tips are blunt, they may be removed, rotated (indexed) and replaced to present a fresh,
sharp face to the work piece. This increases the life of the tip and thus its economical cutting life.
DRILL BITS
Drill bits are cutting tools used to create cylindrical holes, almost always of circular
cross-section. Bits are held in a tool called a drill, which rotates them and provides torque and
axial force to create the hole. Specialized bits are also available for non-cylindrical-shaped holes.
The shank is the part of the drill bit grasped by the chuck of a drill. The cutting edges of
the drill bit are at one end, and the shank is at the other. Drill bits come in standard sizes.
SETUP 1 TOOLING LIST
We need to select/create a tool for each of the Machining operations. In the Project
Manager, you can create and automatically assign new tools to tool stations in the Tools view.
You can also create tools from the Machining menu.
SHOP FLOOR DOCUMENTATION
28. TOOLING LIST
MILLING TOOLS
TOOL NAME DESCRIPTION DIAMETER COR RAD FLUTE LEN
ADJ
REG
BALL_MILL Milling Tool-Ball Mill 6.0000 3.0000 125.0000 0
MILL_D20
Milling Tool-5
Parameters
20.0000 0.0000 50.0000 0
CENTER_DRILL_D2.5 Center Drilling Tool 2.5000 1.2500 50.0000 0
CENTER_DRILL_D8.0 Center Drilling Tool 8.0000 4.0000 50.0000 0
MACHINE SETUP OPERATIONS
Face milling
Vertical multi depth milling
Contour milling
Center drilling
Drilling
TOOLS USED IN MILLING OPERATION
The following is a list of Milling tools and the key dimensions that you can set for each tool foe
deckel cover plate:.
Ball Mill
30. The following is a list of Turning tools and the key dimensions that you can set for each tool for
deckel cover plate:.
Drilling Tool
(D) Diameter
(L) Length
(PA) Point Angle
(FL) Flute Length
Flutes
Spot drill
(D) Diameter
(L) Length
(PA) Point Angle
(FL) Flute Length
Flutes
31. FIXTURE DESIGN
A fixture is a work-holding or support device used in the manufacturing industry. Fixtures are
used to securely locate (position in a specific location or orientation) and support the work,
ensuring that all parts produced using the fixture will maintain conformity and
interchangeability. Using a fixture improves the economy of production by allowing smooth
operation and quick transition from part to part, reducing the requirement for skilled labour by
simplifying how workpieces are mounted, and increasing conformity across a production run.
A common type of fixture, used in materials tensile testing
32. CAM GENERATION
SETUP 1
Below image shows the face milling operation.
Below image shows the verification of face milling operation.
33. Below image shows the planar milling operation.
Below image shows the planar milling operation.
Below image shows the vertical multi depth milling operation.
34. Below image shows the verification of vertical multi depth milling operation.
Below image shows the vertical multi depth milling operation.
35. Below image shows the verification of vertical multi depth milling operation.
Below image shows the planar milling operation.
36. Below image shows verification of planar milling operation.
Below image shows the planar milling operation
37. Below image shows verification of planar milling operation.
Below image shows the planar milling operation.
38. Below image shows the verification of planar milling operation.
Below image shows the planar milling operation.
39. Below image shows the planar milling operation.
Final component of crank shaft
40. TOOLING LIST
MILLING TOOLS
TOOL NAME DESCRIPTION DIAMETER COR RAD FLUTE LEN
ADJ
REG
BALL_MILL Milling Tool-Ball Mill 6.0000 3.0000 125.0000 0
MILL_D20
Milling Tool-5
Parameters
20.0000 0.0000 50.0000 0
CONVERT TO NC CODE
Using the post processor we have to convert CL file data into machine specified NC part
program
1. In the Project Manager, select the first operation on the Operations page, then hold down
the Shift key and select the last operation. All the cutting operations are selected.
2. Press the right mouse button and select NC Code from the menu.
3. Select a Machine Format file from the pull down list (3-Axis/5-Axis).
4. Select Apply.
41. RESULTS & CONCLUSION
We have generated 3d model by using unigraphics nx7.5 cad software
NC program for crank shaft is generated using cam software.
Generated NC program is given to CNC machines through DNC lines.
As we have optimized Optimum cutting speed, by using 5-axis machine which has high
flexibility in manufacturing by this we can increase Production rate and optimum cost
criteria in manufacturing of crank shaft.
