Course is focused fundamental
possibilities of automatization of machine
tools and automatization of programme
preparation for CNC machine tools.
 1+2, CA – classified assessment - 3 credits
 Presentations
 Exercises

› common tasks
› individual work
1+2, 1 hour of presentation, 2 of exercise =>
13 + 13 weeks (13+26) => 4 + 9 approx.(12+27)
presentation explain the work on exercise =>
presentation will be together on the
beginning
and then you will have time to make the task
and individual work!
Work on conventional machines is
replaced by automated work on
automatic machines. These
machines are working without
human control with higher speed,
precision, safer and more
productivly than humans.
But where did it start?
Is connected with the rising demands of
society and industry development.
 Is the way to intensification of
manufacturing – increasing productivity,
improving quality and lowering costs
 Is the way to improvements in
manufacturing technology, spreading
the technological possibilities and way to
make the inovation cycle faster.

Tool management
 Tool change
 Tool movements
 Spindle start, devices start
 Material loading
 Finished piece remove

Machine tools:
 general-purpose, manually operated
(conventional);
- The leading power is the worker
Machine tools:
 automated:
a) fixed automation – mechanisms: cams,
gear wheels, links, levers, arms; mechanical
stops, limit switches, etc.
b) flexible automation – program control,
numerical control
Is a disc or cylinder with a curve shaped path. A boss
in support is in the path and as the cam turns the
support moves. Cam are connected together to
provide complex movement of support, feed, rotation
and other.
automatic general-purpose machine
e.g. a semiautomatic or an automatic
lathe
 single-purpose machine (usually unit-built)
workpiece oriented function design
 transfer line
integrated workpiece transport system

Just one operation, of op. Step is done.
 Sometimes a batch of operation steps
 Special machine designed to maximize
the production:

› Multiple spindles
› High feed drives
› Multiple clamping
› Automatic part in feed
› Special tooling usage
Video –
Transfer line

(soft, programable automation) is aimed
at piece and small batch production
due to easy reprogramming.
Two basic forms
 Program sequence control
 Numerical control
The sequence of motions and switchings is
controlled by relays, timers, switches,
perforated tape, programable cylinders,
plugboards and other controllers.
Easier reprogramming, limited program
options, almost no adjustments
Each line presents
a different
movement or
switch. It has to be
printed correctly,
no error control.
FYI:
8 line perforated paper tape can contain one byte of information in one
column of holes. Normal pitch of columns is 2,54 mm. That means you
need 2,6 m of tape to store 1kB of data. A dual-layer DVD is then approx.
22100 km of perforated tape.
The most important type of automation.
Almost all of new machines are
numerically controlled.
Priciple:
Machine and all of its movements are
controlled by a program. Program is a list
of instructions written is specific syntax
and having specific format.


Limitations – speed, length of program,
possible motions on cams.
1.
Conventional machine tool
2. NC machine tool (stand-alone)
3. NC machine tool with tool magazine
4. CNC machine tool

Mechanization – human power is
replaced by machines, drives, hydraulic
or mechanic devices

Automation – human control is replaced
by sequentional machine, cams,
computer, PLC controller

Semiautomatic run – tools are changed
automatically, blank or finished
workpiece is renowed by operator

Automatic run – both the tool and
pieces are placed and removed
automatically by robot (line, tables)
Automatic
Semiautomatic
Tool management
 Tool change
 Tool movements
 Spindle start, devices start
 Material loading
 Finished piece remove

Originaly only NC control was used.
Program was stored on tape or disc and
read one line after another.
Influence of rapid development of
computers resulted to CNC control
(Computer numerical control). Now the
program is loaded into computers memory
and executed from here.
Option
NC control
CNC control
Program length
Limited by data storage
capacity (tape)
Unlimited (limited by data
storage capacity – HDD
drives over 1TB)
Program sequence
One line after another
Allows jump forward,
backward, subprograms.
Jump to other programs
N/A
Yes
Canned cycles
N/A
Yes
Coordinates correction
Manually only
Yes, automatically
Tool length compensation
Manually only
Yes, programable
Tool diameter
compensation
N/A
Yes, programable
Reading in advance
N/A
Yes, continual mode
Start after breakdown
N/A
Yes
NC/CNC machine consist of 3 basic elements.
List of instructions – NC code – a mix of alphabecial and
numerical information. Contaion information about
movements, feed, speed, tool change and other
machine functions (cooling, measuring)
Control unit - control system – converts the program into
signal for machine and send them to machine (PLC
controller)

NC
code
Control
unit
(system)
Machine
Drive
motor
Sensing
device
NC/CNC machine consist of 3 basic elements.
Machine tool – fitted with drive motor to operate
slides, support and spindle. Also with switches
to start/stop specific functions
Sensing device – optional(closed circuit)- sensing
device control if a specific demand was
fullfilled. Support feed, Table position etc.

NC
code
Control
unit
(system)
Machine
Drive
motor
Sensing
device
Three types of motion
1) point-to-point motion – tool is moved to
specific location, path or speed of move
between location is not controlled.
(drilling)
2) Linear control – movement along one of
the axes of the machine.
3) Contouring control – movement can be
made in two or more axes
simultaneously.
Point-to-point control
drilling
Linear control
Contouring control (continual)
milling machines, lathes
machining c.(milling, turning)

MC combine a number of different
machining processes in one operation
All manufacturers around the world
Basic concept:
1) Holder with standadized conecting part
– ISO, BSK cone, CAPTO system etc.
2) Extension bar – active (vibration
elimination) adujstable and balanced
3) Quick change tooltip/insert
Device used for transportation of blank
and semiproduct in production
Types:
Belt conveyor
Pulley(rolls) conveyor
Cradle conveyor
Used for small parts and loose material
 Endless belt made of rubber, plastic
particles, short boards (grids)

For large solid parts and products
 Low force needed (gravity slide ways)
 Use of pallets

Video –
conveyor
Board used for
transportation
Equiped with jigs and
other positioning
elements
Together with pallete
changer is used for
automatic blank
material loading
and parts unloading
aka Switch table
2-4 pallets in one machine
Manual
- Accumulation conveyor
-
- Accumulating pieces to balance production
-
Robot loading
- For single standing, large production usage
(common machine tools)
-
Line(conveyor) loading
- For FMS and large batch production (special
machine tools)
Flexible manufacturing system for 4 types of automobile cylinder heads
(GM 3801 – 3811)
BZ 400
BZ 500
Other
Reserve
Flexible to suit various part variants
9 Flexible transfer machines (some incorporating BZ 400 machining centers),
and 16 high-dynamic BZ 500 machining centers
Completely automated
Approximately 500,000 parts p.a.
-
Cam‘s
FMS
-
CNC tools
-
Conventional tools
-
Cost reducing
(per piece)
Higher
investments
Speed
improvement
Productivity
improvement
Repeatability
improvement
Machining
costs (Kc/pce)
-
Productivity
(pcs/hour)
Flexibility

Programming of machine tools
Machining on CNC machines is controled by
a NC code.
NC code is a list of instructions for the machine
and also for the operator. Instruction are
executed in time order.
NC code must have a specific format so that
the control system of machine is able to read
it.
The tool in machine is moving in
workspace.
 The position of the tool is given by
coordinates.
 We are using different coordinate
systems.
 If we set some coordinates in NC code,
the machine moves the tool to the
specified place.


Basic is orthogonal system
Z
Y
X
Z axis is usually axis of spindle a X axis is the
working axis, or the longest!
Z
Y
X
Z axis is usually axis of spindle a X axis is the
working axis – diameter!!!
X
Z

To set the position we can add rotation
along the axes.
Second set of coordinates
U,V,W resp. P,Q,R etc.
Z
C
Y
B
X
A

Refernce point – a specific point on
machine with given coordinates. Not
always in the workspace of machine.

A special commang G98
Ways how to define a movement
a) Absolute programing – position is in all
point expressed as a distance from zeropoint
b) Incremental programing – position is
expressed as a change from last postion
2.
3.
1.
Absolut
G90 X0 Y0 Z50
2. G0 X15 Y70 Z50
G1 X15 Y70 Z0
3. G1 X25 Y70 Z0
G0 X25 Y70 Z50
1. G0 X0 Y0 Z50

Incremental
G91
G0 X15 Y70 Z0
G1 X0 Y0 Z-50
G1 X25 Y0 Z0
G1 X0 Y0 Z50
G1 X-45 Y-70 Z0

Structure and form of NC code is
standardized by international standard ISO 6983 – Numeric control programs
formating
Differences between different control
system manufacturers and differences
between versions.
Lines (blocks)
Words
Word has a meaning and value part
S
1500
ISO is standardized code (G – code)
Some manufacturers devoloped their own
standard for NC code – native standard
Mazak – Mazatrol
Heidenhein – iTNC
Siemens - Sinumeric
Heading lines
Definition of relation between coordinate
system of CNC machine and program, type
of programing, work mode, working
conditions
 Program body
Cutting and non-cuting moves, main program
and subprograms, tool changes
 Ending lines
Tool return to home point, change to first tool,
coordinates reconstruction

Subprograms
 A link to another then the
following line is entered
into main programm.
 This subprogram is
executed.
 After finishing this
program we return to
main program a we
contiue until end of main
program(M30)
Manual/Hand programing
 Shopfloor programming
 Automated programing








Editors are used. Program is written
manually (by hand) line after line.
Used for simple parts (but complex too)
Toolpath is exactly
defined
Program can be adjusted
to save time
Can use canned cyles
Can be parametrized
Used in mass production
We need to know the functions: (many more function exist)
Movement functions:
G00
rapid movement
G01
linear interpolation/movement
G02/03 circular interpolation
G40 diameter compensation off
G41 diameter compensation on /right handed
G42 diameter compensation on /left handed
Support and help functions:
M06
tool change
M03/04 spindle start CW/CCW
M05
program stop
M30
program end
Specilzed editors
Predator G-code editor
G Wizard
Mikronex





Somewhere in between manual and
automated
Uses cycles with parameters
We have to edit these
parameters manually
But the NC code
is generated
automatically
No postprocessing
Control system use – programming on
machine
- No costs (together with machine)
- Fast use (macros)
- Time waste (program x work)
- Comfort (on machine x in office with PC)
- Shape limitations
Heidenhein
Work with the „sequential NC code
preparation“
 Uses CAM (Computer Aided
Manufacturing) software
 For all parts including complex shapes
 We dont need to compute the toolpath
 We need correct postprocessor

Partprogram – workpiece,
material, cutting
conditions, tools…
Procesor – according to
technology
CL data – virtual toolpaths
on virtual machine
Postprocesor – „translator“
for the specific CAMcontrol systém-machine
combination
NC code – toolpaths of a
real tool on a real
machine
Partprogram
Proceso
r
CL-data
Postproceso
r
NC-kód
is Computer Aided Manufacturing (machining)
From simple 2-axis turning up to multiaxis
machining
 Feature or technologically oriented
 Special types of CAM for special purpose

Live presentation
2D – just in two axis - turning
2,5D – two axis, but in layers – not
simultaneously
3D – three axes simultaneously
multiaxis
4D – four axis - one rotary axis (rotary table)
5D – five axis - maching (two rotary axes)
CAM software uses „Strategies“
Strategy – is a general plan how to
move the tool durign machining
Continual development
Roughing – offset, raster (Zig-Zag
method) plunging
Finishing strategies – pencil milling,
streaming, rest material maching
NX (Siemens PLM software) Catia
(Dassault systémes) – both 10%
market share
PowerMill, FeatureCAM, ArtCAM
(Delcam company) ,InventorCAM
(Autodesk) Wildfire – Pro/Ingineer
(PTC) – 5%
EdgeCAM, SurfCAM, SolidCAM,
MasterCAM, OneCNC, ESPRIT,
GibbsCAM
Simulation is used to
control generated
toolpaths for
following reasons:
- Colisions
- Undercuts (or rest
material)
- Postprocesing
check
NX
We can do complex shapes, no need to
calculate control points
 We can use simulation and verification
 We can change the tool easily
But
 We need postprocessor
 Expensive (SW, computer, learning…)
 Program is always longer (again
expensive)


ArtCAM

FeatureCAM
Projects
- Common – same tasks for all
- Individual – own selection of part and
individual work on it. Evaluated.
Test – from theory of automation and
programming