sinumerik
s
We are part of the
workshop team
Valuable information for those interested in CNC
2
2nd and revised edition
This brochure was created as a joint effort between
SIEMENS AG
Automation and Drive Technology
Motion Control Systems
Erlangen
You can obtain additional information under:
http://www.siemens.de/SINUMERIK
http://www.siemens.de/jobshop
and
R. & S. KELLER GmbH
Didaktik + Technik
Wuppertal
3
Foreword
This brochure is intended for everybody who is interested in modern
production techniques. It supports the Siemens workshop initiative
called JobShop, whose goal is to make it easier to work on lathes and
milling machines.
For the layman, this brochure should motivate him to look into this
extremely diversified future-oriented industry sector. Professionals
will enjoy reading about subjects which they know about in-depth in
a somewhat lighter vein.
Laymen and professionals will be able to get to know the new
SINUMERIK 810D control system with ShopMill and ShopTurn.
Its graphic HMI makes it very easy to familiarize yourself with and
productively work with CNC machines.
With this brochure, entitled "We belong to the workshop", enter into
a partnership with Siemens in the sense of creating an attractive,
future-oriented and cost-effective workshop.
Erlangen / Wuppertal, January 2001
4
5
We are part of the workshop team
1Technology for the benefit of the human race
Siemens technology worldwide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Technology around us. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Production technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Ideas ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2Machines make state-of-the-art technology possible
A glance back into history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
On the way to perfection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
The operator and his machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
The wide range of CNC turning and milling machines . . . . . . . . . . . . . . . . . . . . 15
SINUMERIK controls yesterday and today . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
The axes - no cutting without motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
The drive - no power without strong muscles. . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3Work must be planned
The NC program - how do I tell my machine? . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Thoughts in motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Where it all happens: Room for motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Straight to the point. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
When it has to be fast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
6
4How workpieces are formed ...
Contours consist of straight lines and arcs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
How straight lines are programmed according to DIN . . . . . . . . . . . . . . . . . . . . . 26
Basics when programming arcs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
How arcs are programmed according to DIN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Graphic programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Contours and tool paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
5... and how they are produced
Tools today . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Tools in use* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
When something turns* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Speed and time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
The circumferential speed at different diameters . . . . . . . . . . . . . . . . . . . . . . . . . . 44
The circumferential speed at various rotational speeds . . . . . . . . . . . . . . . . . . . . . 45
The cutting speed: when a tool cuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Feed and surface quality. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Constant cutting speed manually controlled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
6The optimum technology is important
Milling with ShopMill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Turning with ShopTurn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Detailed quality for the perfect fit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Index
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Diagrams/Photographs
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
7
1 Technology for the benefit of the human race
1.1 Siemens technology worldwide
Siemens, leading-edge solutions - on all continents
Relay technology
PLC
Communications Micro-electronics
High-tech for racing cars
Control technology
ICE 3
Power utility technologyDomestic appliances
8
1.2 Technology around us
The things around us comprise
the widest range of components.
Not only are different materials used, but they
also come in all shapes and sizes.
The most important techniques for producing
these "round" and "square" shapes will be
discussed.
9
1.3 Production technology
The most important production techniques required to machine these parts are:
Workpieces can be produced according to the various requirements by turning
and milling.
Square parts
are generally
milled.
Turning
Milling
Round parts
are generally
turned.
Workpieces can be produced on lathes and
milling machines with a repeat accuracy of just
a few micrometers and with mirror surfaces.
The precision is several times better than the
thickness of a human hair (0.05 mm).
10
1.4 Ideas ...
The mechanical design engineer specifies the dimensions and the surface qual-
ity of the workpiece.
From this the technical draftsman generates the technical drawing as a basis for
production.
Damper of a
steering assembly
Sealing plate of a
grinding machine
11
... implemented with technology
Before production
starts, the program
must first be written.
s
The program is then directly converted
into chips.
For these cutting technologies, skill and
experience play an extremely important
role.
12
2 Machines make state-of-the-art technology possible
2.1 A glance back into history
As soon as man started to work with stones
and to manufacture tools to help him do this,
he had to construct devices for drilling.
This can be considered as the start of ma-
chine tool development.
The Middle Ages with
the turning and drilling
equipment of the trades
represented the first ma-
jor milestone. Either
people or water were
used as the prime mov-
ers.
The Industrial Revolution in the 18th/19th
centuries was the next major milestone:
The advent of the steam engine as a "powerful
drive" and the cross-slide are important events
in the history of machine tools.
This picture illustrates the tedious
work with the chisel and the more
comfortable way of working with
the cross-slide. Conservative opera-
tors looked down on it and called it
"going car".
Drilling device with bow-type drive
(5000 B.C.)
Operator on the lathe
(approx. 1425)
D
rilling machine with water-powered drive
(approx. 1615)
James Watt (1796 to 1819),
inventor of the steam engine
Henry Maudalay (1771 to 1831),
inventor of the cross-slide
Old lathe and spindle lathe
13
2.2 On the way to perfection
Well-conceived mechanical designs for all of the modules used in machine
tools were distinctive features of progress in the 19th century.
Initially, the machines were driven
from a central drive through transmis-
sion belts.
Later, machine tools had their own
individual drives, which resulted in
higher productivity in the man/ma-
chine combination.
Cone-pulley drive with back gears
Cross-slide
Tailstock
Lathe shop (approx. 1850)
Lathe shop (approx. 1950)
Lathe (approx. 1916)
14
2.3 The operator and his machine
* CNC stands for "Computer Numerical Control", i.e. a machine with a computer
that controls the machine with numerical data.
Conventional milling (approx. 1950)
Conventional turning (approx. 1950)
Conventional drilling (approx. 1950)
A
ny
b
o
d
y v
i
s
i
t
i
ng ex
hibi
t
i
ons to
d
ay,
might think that only CNC-type ma-
chines* are in use. But that’s not true.
Today, more conventional machines
than CNC machines are still being built
worldwide.
Conventional machines are still
used for simple workpieces due
to their lower price.
15
2.4 The wide range of CNC turning and milling machines
... with a central
solution for all.
16
2.5 SINUMERIK controls yesterday and today
1952 Massachusetts Institute
of Technology (MIT)
The first NC-controlled machine tool
was built here (the control still used
tubes). It was used to simplify pro-
duction of increasingly more com-
plex parts and components for the
aircraft industry.
1960 Siemens NC control
In 1960, the first numerical control
was built using relay technology.
1967 SINUMERIK System 200
The first point-to-point and path con-
trol for turning and milling.
1976 SINUMERIK System 7
The first path control using micropro-
cessors and semiconductor memories
instead of relays is introduced.
1977 SINUMERIK Sprint T
Workshop programming first estab-
lishes itself in turning in the world of
CNC path controls.
1981 SINUMERIK System 3
A modular CNC path control for
turning, drilling and milling up to
four axes is developed, a control sys-
tem with a wide range of applica-
tions.
17
1984 SINUMERIK 810
A compact CNC path control for four
axes and one spindle is developed for
turning and milling.
1986 SINUMERIK 880
This modular CNC path control, with
up to 24 axes and 6 spindles (16 chan-
nels) is developed for the upper per-
formance range.
1994 SINUMERIK 840D
This modular control concept was
conceived for even more flexible and
favorably-priced production. It was
integrated in the same packaging de-
sign as the drive. It includes both
hardware-independent software as
well as interfaces to the digital drives.
Siemens was the first to develop and
implement Nurbs interpolation for
CNC technology.
1996 SINUMERIK 810D
The NC controls and drives were
consistently further developed and
combined to form a single module in
this control. The control software is
based on SINUMERIK 840D.
1998 ShopMill
2000 ShopTurn
Production of components on lathe
and milling machines is made ex-
tremely simple using a modern pro-
gramming HMI in line with the
requirements of operators and work-
shops. This concept, based on the
810D, is implemented for milling
with ShopMill, and for turning with
ShopTurn.
18
2.6 The axes - no cutting without motion
Modern production on turning and milling machines requires that workpieces
and tools are moved. Thus, today's machine tools with a main drive (shown in
blue) and with axis drives (shown in red) are equipped for motion in different
directions:
Ball screws, drive motors ...
Light source
Glass scale Silicon photo element
... and the measuring system, are the
essential components of a control cir-
cuit for high-precision production.
19
2.7 The drive - no power without strong muscles
Werner von Siemens (1816 to
1892) is the father of drives. A
new era of energy conversion be-
gan with his invention of the dy-
namo machine back in 1866.
For fast and precise production, powerful,
variable-speed motors are required for the
main drive...
... and feed motors.
The linear motor is considered to be the innovative
drive of the future. Higher acceleration levels and
velocities (up to 120 m/min for machine tools) can
be achieved by eliminating mechanical transmis-
sion elements.
Siemens axis drive motors with acceler-
ation rates up to 450 m/s2
Siemens main spindle motor with a rated
output of up to 37 kW
1 Guide system
2 Secondary section
3 Primary section
4 Linear position measuring system
Principle of operation of a
linear motor
20
3 Work must be planned
3.1 The NC program - how do I tell my machine?
Whether yesterday’s punched tape ...
...even today, nothing moves without clear instructions which the control sys-
tem understands.
... or tomorrow’s voice instruc-
tions ...
21
3.2 Thoughts in motion
Consider the following task: The milling tool has to
rotate clockwise with a speed of 1650 revolutions per
minute.
Initially it should travel vertically downwards to a
depth of 10 mm and the tool should then mill the com-
plete right-hand longitudinal
side to produce a smooth,
shiny workpiece surface.
This is achieved using a feed
velocity of 100 millimeters per
minute. The tool should then re-
tract quickly to the initial
position. Ready!
As usual, there are various ways of achieving this goal:
One of the shortest ways is a "special" language which
the machine tool specialist calls DIN 66025.
The task mentioned above is defined as follows in this language:
N1 F100 S1650 T24 M3
N2 G0 Z-10
N3 G42
N4 G1 X0 Y15
N5 G1 X74,3
N5 G40
N6 G0 Z100 M30
This widely established language is really very abstract. Furthermore, for
workpieces with complex shapes its limits are quickly reached and points must
be calculated. Today, it is far faster and simpler to use
graphic programming.
You will clearly see this on
the following
pages with the
Siemens
control operator
interfaces
ShopMill and
ShopTurn.
22
3.3 Where it all happens: Room for motion
Not every workpiece fits every machine.
The maximum workpiece dimensions correspond to the possible traversing
path of the tool in the particular axis.
Max. turning diameter Axis X
Max. turning length Axis Z
Max. workpiece length Axis X
Max. workpiece width Axis Y
Max. workpiece height Axis Z
Flatbed machine
(all the following displays
refer to this machine type)
Inclined bed machine
(ShopTurn is used on most
of these machine types)
23
3.4 Straight to the point
There are several reference points on every CNC machine which are extremely
important for program execution.
The manufacturer defines the machine zero M and this cannot
be changed.
It is located at the origin of the machine coordinate system.
The workpiece zero W (also known as program zero) is at the
origin of the workpiece coordinate system. It can be freely se-
lected, and should be located at the point where most of the di-
mensions originate in the drawing.
The reference point R is approached to set the measuring sys-
tem to zero, as the machine zero point can generally not be ap-
proached. The control starts to count in its incremental position
measuring system.
After they have been installed, all
tools have a fixed measured ref-
erence point. The control system
must know dimensions X and Z,
and R and L so that each of these
different dimensions can be taken
into account when positioning.
Masch
i
ne
zero M
Workp
i
ece
zero W
Re
f
erence
point R
24
3.5 When it has to be fast
"Time is money" is also true for CNC machines. The tool has to travel quickly
from the starting point to the workpiece.
G0*
signifies
rapid
traverse
* G0 is the
abbrevia-
tion for G00
Today's CNC machine tools achieve extremely high traversing rates.
Although these only correspond to the velocity of a pedestrian, for a machine
tool they are quite adequate as generally only short travel paths are used: The
target is reached in seconds ñ and, without a visible braking distance.
Traversing the tool is similar to driving to work ñ you need to watch out for
obstructions.
In order to save time, the tool is moved as close as possible to the workpiece.
When experienced at close quarters, this operation is highly impressive ñ even
for professionals.
25
4 How workpieces are formed ...
4.1 Contours consist of straight lines and arcs
Turned and milled workpieces and therefore their contours can generally be de-
fined using straight lines and arcs.
Each arc can be produced from the left or from the right, similar to a curve in
traffic, which, depending on the direction of travel, is either a right-hand or left-
hand arc.
Contour of a turned part
Contour of a milled part
26
4.2 How straight lines are programmed according to DIN
According to DIN 66025, all straight lines are programmed using function G1
(short form of G01). In this case, the end point in X and Z is generally specified
using absolute coordinates.
The starting point of the contour is X0 / Z0.
G1 X20 Start of the chamfer (24-2*2)
G1 X24 Z-2
G1 Z-28 Start of the arc (30-2)
Arc
G1 X36 Start of the arc (40-2*2)
Arc
G1 Z-40
Arc
G1
or
G91 G1
Z-70
Z-10
Absolute ("ABS")
G91 stands for incremental ("INC")
(G90)G1 X60 Z-75,774 Value U can be determined using the
tangent function as DIN does not
permit any angles to be entered.
G1 Z-100
27
When milling, axes X and Y are programmed with function G1 (and for depth
infeed, also the Z axis).
G1 Y65 Start of the arc (90-25)
Arc
G1 X115 Start of the arc (140-25)
Arc
G1 Y50 This value can be determined using
rigonometrical functions
Arc
G1 X100 Y10
G1
or
G91 G1
X80
X20
Absolute ("ABS")
G91 stands for incremental ("INC")
(G90)Arc
G1 X10
28
4.3 Basics when programming arcs
If an arc is to be programmed, the direction of rotation must first be defined.
The following is valid according to DIN:
*Abbreviations for G02 / G03
While this definition is easy to understand for CNC milling machines, there is
a "problem" for all CNC-controlled lathes due to the various machine types, i.e.
flat-bed or inclined-bed machines:
What is G2, what is G3?
Due to the quite complicated "three-finger rule", derived from the DIN stan-
dard, G2 and G3 can also be defined as follows:
•G2 is an inner arc,
•G3 is an outer arc.
G2*
Clockwise
G3*
Counter-
clockwise
29
When programming arcs, both the end point (and also the direction of rotation)
and the center point must be specified.
As when using a compass, the starting point A, the center point M and the final
point E must precisely coincide.
coincides does not coincide
The center point M is always specified with reference to the starting point A:
The following applies:
•I belongs to X, K belongs to Z.
•In order to define the sign, always look from A to M and compare with the co-
ordinate axes.
30
4.4 How arcs are programmed according to DIN
Turned part
Up until now, the individual contour sections were designated in the program
with a, s, d etc. However, according to DIN, N1, N2, N3 etc. must be written.
The NC program for the contour above:
N1 G1 X20
N2 G1 X24 Z-2
N3 G1 Z-28
N4 G2 X25 Z-30 I2 K0 K is 0, as the starting and center point
have the same Z value.
N5 G1 X36
N6 G3 X40 Z-32 I0 K-2 I is 0, as the starting and center point
have the same X value.
N7 G1 Z-40
N8 G2 X40 Z-60 I17,321 K-10 The I value can be calculated using the
Pythagorean theorem.
N9 G1 Z-70
N10 G1 X60 Z-75,774 (refer to page 26)
N11 G1 Z-100
31
Milled part
The NC program for the contour above:
N1 G1 Y65
N2 G2 X35 Y90 I25 J0 J is 0, as the starting and center point
have the same Y value.
N3 G1
N4 G2 X115 Y65 I0 J-25 I is 0, as the starting and center point
have the same X value.
N5 G1 Y50 (refer to page 27)
N6 G2 X132 Y34 I-20 J0 The values for X and Y can be deter-
mined using trigonometrical func-
tions.
N7 G1 X100 Y10
N8 G1 X80
N9 G3 X30 Y10 I-25 J-31,225 The value for J can be calculcated us-
ing the Pythagorean theorem.
N10 G1 X10
32
4.5 Graphic programming
On the previous pages, you have seen how difficult it can be to program a con-
tour according to DIN.
On the following pages you will see, how simple it is to graphically program
contours by way of an example of ShopTurn and ShopMill.
Graphically programming a turning contour with ShopTurn
Graphic programming using ShopTurn is not only simpler, but it is also far
faster, especially for complex contours.
The chamfer 2*45° is simply
"attached" to the path.
The rounding R2 is simply "attached"
to the path.
33
Graphically programming a milling contour using ShopMill
Rounding R25 is simply "attached" to
the path.
34
4.6 Contours and tool paths
To obtain a precisely dimensioned workpiece, the tool geometries must be ob-
served, both when turning and when milling.
Turning tool
Turning longitudinally and face turn-
ing, no dimension deviations occur,
in spite of a rounded cutting surface.
Tool path NOT corrected
For taper and also radius turning, di-
mension deviations occur if the tool
path is not corrected.
Tool path corrected.
Milling tool
However, imagine the milling cutter
were to move along the contour with
its center point.
Tool path NOT corrected
The larger the radius, the smaller the
remaining volume which has to be
removed.
Tool path corrected.
35
If the tool is corrected using the control system’s "intelligence" (instead of the
tedious tool path calculation in the path in parallel to the contour), then the spe-
cialist talks about
Tool nose radius and Cutter radius
compensation correction
Compensation or offset correction is implemented using the two functions
G41 and G42 :
Direction of motion = direction of view
G41 The tool is located to the left of the contour.
G42 The tool is located to the right of the contour.
G40 cancels G41 and G42.
G41
G42
36
5 ... and how they are produced
5.1 Tools today
When turning and milling, as is true for any cutting operation, the cutting ma-
terials and their resistance to wear are especially important. .
Whereas previously alloyed and non-alloyed tool steels dominated, in the sum-
mer of 1998, the distribution is as follows:
Carbide metal HSS CBN+PCD
(high-alloyed high-speed (cubic boron nitride+
steel tool) polycrystalline diamond)
The proportion of ceramic cutting materials is under 1%.
8%
33%
59%
Carbide metal
The increasing use of
this coated sintered ma-
terial means that ma-
chining can be
p
erformed at extremely
high cutting speeds
HSS
Spiral drill, sinker,
reamer, ...
Machining is performed
at low cutting speeds.
CBN
Suitable for roughing
and finishing hardened
steel and also for cast
iron.
37
Productivity using state-of-the-art tools
Under the title "Costs reduced - how you can save when cutting", Edition 24 of
the PRODUKTION trade periodical of 10.6.98 reported on some insider infor-
mation from a machine tool OEM.
The report included statements which appeared unbelievable for the "standard"
operator:
"Trials at SECO have shown that when finishing cast iron brake
disks, ceramic cutting tools had a lifetime of approximately 40
brake disks at a cutting speed of 500 m/min.
With the same cutting speed, CBN-30 cutting tools had a lifetime
equivalent to 500 brake disks; if the cutting speed is doubled, the
tool lifetime was a factor of 6 higher, i.e. 3000 brake disks."
SECO were contacted for an explanation, this is what they said:
"These values come from our experience in the field. We cannot give any de-
tailed explanation."
One thing is quite correct, the wear properties when machining grade 25 cast
iron with CBN improve the higher the cutting speed.
These "unbelievable" statements can be compared with the "contradictions" of
carbide metals:
Individual materials with their particular properties are combined so that a new
carbide metal material is formed which only has the required properties of the
individual materials.
Titanium/tungsten carbide + Cobalt →Carbide metal
hard soft hard
brittle tough tough
38
The carbide metal inserts are produced for the widest range of materials (steel,
cast iron, aluminium) and with a wide range of different geometries. The ma-
chining type (coarse or fine machining) also determines the carbide metal type
selected.
Comprehensive cutting data cata-
logs from all of the tool manufac-
turers are available to select the
optimal inserts.
39
The clamping system and clamp type depend on the machining situation, the
properties of the workpiece and the insert type.
The name reversible insert
comes from the fact that these
inserts can be re-clamped in the
clamp when one of the cutting
edges is worn so that a new cut-
ting edge is available.
You will find general
nominal values for ma-
chining using carbide
metal inserts in the var-
ious books of tables.
40
5.2 Tools in use*
Plunge cutting
with a 3 mm wide
grooving tool
Longitudinal
roughing
with a 55° insert
Inner face turning
* The diagrams on this and the
next pages are video
sequences from the Siemens
CD "We belong to the work-
shop".
41
Roughing
an external contour
Horizontal machining
with NC rotary table
Finishing
high alloyed steel
42
5.3 When something turns*
The workpiece speed when turning ...
... and the tool speed when milling ...
... are prerequisites for machining.
* The diagrams on this and the next pages are video sequences from the Siemens CD "We
belong to the workshop team"
43
5.4 Speed and time
The higher the speed the shorter the time in which the workpiece turns through
one complete revolution.
For a speed of n = 30 RPM, one revolution takes 2 seconds.
For a speed of n = 60 RPM, one revolution takes 1 second.
44
5.5 The circumferential speed at different diameters
For a
small diameter
(and constant speed),
the circumferential speed is low.
The circumferential speed can be
calculated using the following
formula.
v = d * π * n
For a
large diameter
(and constant speed),
the circumferential speed is high.
45
5.6 The circumferential speed at various rotational speeds
With increasing speed (and constant diameter), the circumferential speed in-
creases.
The circumferential speed is generally specified in m/min.
For an assumed diameter d = 60 mm (0.06 m), and a speed n = 120 RPM, the
following is obtained:
v = d * π * n
v = 0,06m*3,14*120 1/min
v = 22,6 m/min
46
5.7 The cutting speed: when a tool cuts
The cutting speed, unlike the circumferential speed, measures the speed of the
tool relative to the workpiece when cutting.
At the same speed n=750 RPM, the cutting speed can be different, depending
on the workpiece diameters.
In order to achieve optimum tool use, it must be possible to select various
speeds:
Larger diameter = lower speed etc.
47
5.8 Feed and surface quality
In addition to the cutting speed
(and the tool nose radius), the feed
especially influences the surface
quality.
Generally, the following is valid:
The lower the feedrate, the better
the surface.
When turning,
the feed
is specified in mm:
f = 0,3 mm
Input when programming:
When milling, the feedrate is
specified in mm/min:
vf = 200 mm/min
Input when programming:
F 0.3
F 200
48
5.9 Constant cutting speed manually controlled
When face turning, it is tedious to keep adjusting the speed to maintain an op-
timum cutting speed.
At an excessive speed (n = 240 RPM), the tool will be destroyed, at a speed
which is too low (n = 60 RPM), the tool will not cut optimally.
At a speed of n = 120 RPM, the tool cuts optimally which means that higher
speeds must be selected at an ever increasing rate.
For those who are
interested:
would be the in-
stantaneous diame-
ter at which the tool
is cutting.
dv
πn⋅
----------
=
vdπn⋅⋅=
d
12000 mm
min
----------
314,120 1
min
----------
⋅
------------------------------------
=
d 318mm=
49
Constant cutting speed controlled by the control system
For all CNC lathes, a constant cutting speed can be selected:
The control system calculates the appropriate speed as a function of the partic-
ular (actual) diameter.
The operator only has to specify the required cutting speed, in this case,
vc = 120 m/min.
In the specialist’s language, this is known as
The cutting speed (an empirical value or from the book of tables), depends on
many parameters, e.g.:
•Tool material
•Workpiece material
•Required surface quality
•Coolant
•Machine (stability, ...)
• Clamping (projection, ...)
G96 S120
50
6 The optimum technology is important
6.1 Milling with ShopMill
In the following, you will see, using as an example a component from a grind-
ing machine, how you can quickly progress from the drawing to your milled
part using ShopMill, graphically supported and without requiring any pro-
gramming know-how.
51
Before we get going
To start off with the exercise has to be given a name
That is also true for ShopMill programs.
But, just like a child, the program isn’t given a run-of-the-mill number, but a
real name. Just like everything else in ShopMill.
First, you define the unmachined dimensions, the retraction plane, the safety
clearances and the main spindle axis.
52
Facing
The workpiece is to be face machined in the first working step. In this case, a
milling cutter has already been recommended for the facing ...
... Of course you can select any other tool from the list. You will find all of the
parameters which you require next to the tool names:
geometrical and technological values, coolant, compressed air ...
The tool usage time is also monitored - the so-called tool life monitoring.
Even so-called replacement tools and flexibly-coded tool magazines can be
administered. For oversized tools, the adjacent positions are also automatically
taken into account.
53
Help graphics for every data entry
Let’s stay with the selected
size 63 milling cutter
The cutting data for the facing
must now be specified. There is a
plain text display for each input
field, and if required, a help
screen.
This means that you can
quickly get to learn
ShopMill without any
long training period.
There is no coding or pro-
gramming to learn. All of
the inputs are made using
input masks with graphic
support.
The first machining step has, in
the meantime, been transferred
into the machining step list.
The facing is symbolized using a
pictogram. The most important
data of particular machining step
is always displayed at the side -
well arranged and to be read at a
glance.
54
Circular pocket
The continuous circular pocket is now to be milled at the center.
You have access to a wide range of plunge strategies.
Depending on what your tool can best handle, it can be fed centered,
oscillating or in a spiral.
You can check your inputs using a simulation graphic.
55
Creating complex contours
So you reckon this is going to be
somewhat more difficult with a
complex outer contour?
Wrong! Even if your drawing is
not dimensioned for NC machi-
ning, ShopMill’s contour
computer and the graphic display
are there to support you.
Rounding-off and chamfers are
absolutely no problem. They are
simply "attached" to the previous
element.
It doesn’t make any difference if
dimension in the drawing is
specified in absolute or incre-
mental terms. You can toggle
between them simply by
clicking. Furthermore, an
integrated calculator can be
called up from every input field.
If a contour element is not fully
dimensioned, it can be defined
using the subsequent elements.
As soon as all of the dimensions
are known, the graphic is updated.
The contour is completely defined
in just minutes - without any
mathematical operations.
56
Roughing along a contour
Using a size 30 cutter, the workpiece will now be roughed along its contour.
The machining step is simulated.
57
Finishing along a contour
A bracket symbolizes the link between the contour and the machining steps.
The screen shows the
finishing operation at an
"obvious" position of the
workpiece - zoomed-in.
Then the contour is
finished using a size 12
milling cutter.
58
Pocket with islands
In this case, it is the other way around, two contours are linked by one machin-
ing operation. The first contour defines a pocket, and the second, an island
within this pocket.
Pockets, with up to twelve complex islands can be solid machined parallel with
the contour using ShopMill. This includes identifying and removing the
residual material, if a large milling cutter was used for roughing. The benefit -
you save time!
You can always toggle between the operating steps and the graphics with a
simple click.
59
Linking drilling patterns
Once all the milling operations
have been completed, it is time to
drill.
In order to avoid having to change
the tool early on, initially, all of
the drilling patterns and individ-
ual holes are centered. You can
also clearly see the linking in this
list of machining steps.
The screen shows the
input mask for
defining a "circle"
drilling pattern with
help screen.
You can quickly, simply and indi-
vidually enter the positions of the
holes, pockets, grooves etc., using
this mask.
60
Linking drilling operations
A position pattern can be linked with various machining operations.
... but they can also be
displayed as a side view.
This allows you to immediately
see whether you entered the
correct drilling diameter and
drilling depths.
All good things come in
three’s:
In addition to the top view and
side view, there is also a help
screen for this input mask.
The two technological
elements (drilling and
thread cutting) not
only can be shown
as top view to
optically check the
data entries ...
61
Simulation
After the last machining step, you can simulate everything once again to check:
Firstly the circular
pocket ...
... and then finish this
contour with a size 12
milling cutter etc.
... then rough the outer
contour with a size 30
milling cutter ...
62
The finished workpiece in 2D
The screen shows a top view of the part after the machining has been
completed ...
... or a view from three sides.
63
The finished workpiece in 3D
The 3D screen is especially transparent. Here, you can view the workpiece
from various sides, and the cross section.
And as always: After theory, it’s time for practice!
64
6.2 Turning with ShopTurn
In the following, you will see, using a swivel damper from a steering system,
as example how you can use ShopTurn to quickly obtain a turned part from the
drawing - graphically supported and without any programming know-how.
65
Before we get going
In the first step, you define the unmachined part type, unmachined part
dimension, the retraction plane and the tool change point. Furthermore, you can
define the speed limits for up to three spindles.
Initially, the workpiece should be faced. In this case, an 80° lathe tool is already
offered for the facing …
66
Tool list
... It goes without saying that you could also select any other tool from the list.
All of the geometry and technological values which are required are available
after the tool name …
… Naturally, you can compensate the tool wear using the fine offsets, and you
can monitor the tool lifetime as well as the number of times that the tool is used.
67
Facing
After the tool has been selected, the technology and geometry data must be en-
tered. In this case, when required, there is a clear help display for each display.
Neither coding nor programming
is required.
You can start to use ShopTurn
with almost any training.
The first machining step has in the
meantime, already been included
in the working step list.
A pictogram symbolizes stock
removal with the data for facing
The most important technological
data of the working step are pro-
vided next to it - always precise
and transparent.
You can check your entries using
the simulation graphics. Here, you
can also read the total production
time.
68
Creating complex contours
And you think that it will be
more difficult with the com-
plex outer contour? Wrong!
If the drawing isn't provided
with dimensions for NC ma-
chining, then the ShopTurn
contour computer comes to
your aid..
If the dimension system of
your drawing allows various
geometrical solutions, …
… then simply graphically
select the optimum solution.
69
This means that even complex geometries are quickly created using clear,
transparent symbols and easy to understand inputs.
Stock removal against contour
The workpiece is now to be roughed against the contour using the 80° lathe
tool.
70
The finishing allowance is set
to zero because the contour
isn't to be finished.
As the negative gradient
contours cannot be machined
using the 80° tool, the relief
cut field is set to no.
A bracket symbolizes the logic
operation between the contour,
entered in line N15 and the
machining step.
71
Simulation
Just like always, the simulation displays the result of your entry …
… and you can clearly see the current workpiece condition in the 3D view.
72
Machining residual material
Now, the negative gradient contours should be machined using the 35° V
chisel, because only this tool can remove residual material.
This working step is automatically linked with the contour entered in line N15.
73
Different workpiece views
And, to be on the safe side,
simulation…
… with the final 3D display
for checking.
You can then obtain a
complete overview of your
production situation in the
3-window view which is also
provided.
74
Rechucking
In addition to a hole and the grooves, two spigots have to be milled on the
lefthand side of the workpiece. This is the reason that a new machining plan
with a short unmachined part is created.
Making grooves
If you wish to create several, similar grooves, then this does not present a
problem. Simply enter the number of grooves and the clearance between them
and ShopTurn does the rest for you.
75
Drilling
Also when drilling, for each input
field, a help text is displayed at the
top next to a help display.
Milling operations on the lathe
No need to worry about milling on
a lathe!
Using ShopTurn, it is also quite
simple and straight forward. In ad-
dition to the simple square spigots
shown here, derived from
ShopMill, it is also possible to
machine complex pockets and
islands - both for face as well as the peripheral surfaces!
The process plan with complete machining
This is the work plan …
76
… with the grooving …
… and the hole …
… and with face milling!
The work plan which can be
simply created even for com-
plex workpieces, in conjunc-
tion with such transparent 3D
graphics, allows you to even
integrate one-chuck machin-
ing simply and easily into your
production environment.
77
And the chips keep going!
Practice always follows theory …
… practice, which with ShopTurn, is fun - lots of fun!
78
6.3 Detailed quality for the perfect fit
In spite of state-of-the-art production technology, incorrectly dimensioned
workpieces can occur due to, for example, worn tools, vibrations etc.
Personnel must check (at least randomly) whether the workpiece corresponds
to the specifications in the technical drawing
Measuring
the complete length of
132.15 mm of the work-
piece using a
caliper
Checking
the diameter
20,2 ±0,03 mm with a
limit gauge
79
In a photo-montage, the mounting location of the damper assembly can be seen
within the steering assembly.
The steering assembly shown above is used for this commercial vehicle.
80
Measuring
the plate thickness using
an external micoro-
meter
When measuring, a specific dimension is determined. The measuring accu-
racy depends on the measuring device (caliper, external micrometer, ...).
Checking
the bore with a
tolerance-plug gauge
When checking, a specific dimension is not determined. It is determined
whether the workpiece is "GOOD" or "WASTE" at the checked location.
81
Installed sealing plate on the drive motor of the grinding disk
Overall view of the tool grinding machine showing the drive motor
82
Index
A
Absolute dimensioning . . . . . . . . . . . . . 26
Arc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Axes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Axis drive . . . . . . . . . . . . . . . . . . . . . . . 18
B
Book of tables . . . . . . . . . . . . . . . . . . . . 39
C
Calculator . . . . . . . . . . . . . . . . . . . . . . . 55
Caliper . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Carbide metal . . . . . . . . . . . . . . . . . . . . 36
Carbide metals . . . . . . . . . . . . . . . . . . . . 37
CBN . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Chamfer . . . . . . . . . . . . . . . . . . . . . . 26, 32
Checking . . . . . . . . . . . . . . . . . . . . . 78, 80
Circle center point . . . . . . . . . . . . . . . . . 29
Circle end point . . . . . . . . . . . . . . . . . . . 29
Circular pocket . . . . . . . . . . . . . . . . . . . 54
Circumferential speed . . . . . . . . . . . 44, 45
Clamping holder . . . . . . . . . . . . . . . . . . 39
CNC lathes . . . . . . . . . . . . . . . . . . . . . . 15
CNC milling machines . . . . . . . . . . . . . 15
CNC path control . . . . . . . . . . . . . . . . . 17
Cobalt . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Commands . . . . . . . . . . . . . . . . . . . . . . . 20
Contour . . . . . . . . . . . . . . . . . . . . . . . . . 25
Contour computer . . . . . . . . . . . . . . . . . 55
Contour milling . . . . . . . . . . . . . . . . . . . 40
Control loop . . . . . . . . . . . . . . . . . . . . . . 18
Conventional machines . . . . . . . . . . . . . 14
Coolant . . . . . . . . . . . . . . . . . . . . . . . . . 49
Cross slide . . . . . . . . . . . . . . . . . . . . . . . 12
Cut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Cutting data . . . . . . . . . . . . . . . . . . . . . . 53
Cutting edge . . . . . . . . . . . . . . . . . . . . . 39
Cutting material . . . . . . . . . . . . . . . . . . . 36
Cutting radius compensation . . . . . . . . . 35
Cutting speed . . . . . . . . . . . . . . 37, 46, 47
Cutting speed, constant . . . . . . . . . . 48, 49
D
Dimension deviation . . . . . . . . . . . . . . . 34
Dimension reference point . . . . . . . . . . 23
Dimensions . . . . . . . . . . . . . . . . . . . . . . 10
Dimensions of unmachined parts . . . . . 51
DIN 66025 . . . . . . . . . . . . . 21, 26, 27, 28
Direction of rotation . . . . . . . . . . . . . . . 28
Drilling . . . . . . . . . . . . . . . . . . . . . . 60, 75
Drilling device . . . . . . . . . . . . . . . . . . . . 12
Drilling patterns . . . . . . . . . . . . . . . . . . . 59
Dynamo machine . . . . . . . . . . . . . . . . . . 19
E
EASYSTEP (mode) . . . . . . . . . . . . . . . . 50
Electron tubes . . . . . . . . . . . . . . . . . . . . 16
Experience know-how . . . . . . . . . . . . . . 11
External micrometer . . . . . . . . . . . . . . . 80
F
F address . . . . . . . . . . . . . . . . . . . . . 21, 47
Face grooving . . . . . . . . . . . . . . . . . . . . 40
Face turning . . . . . . . . . . . . . . . . . . . . . . 40
Feed . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Feed motor . . . . . . . . . . . . . . . . . . . . . . . 19
Finishing . . . . . . . . . . . . . . . . . . . . . . . . 41
Finishing allowance . . . . . . . . . . . . . . . . 70
Flatbed machine . . . . . . . . . . . . . . . 22, 28
83
G
G0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
G1 . . . . . . . . . . . . . . . . . . . . . . . . . .26, 27
G2, G3 . . . . . . . . . . . . . . . . . . . . . . . . . . 28
G40, G41, G42 . . . . . . . . . . . . . . . . . . . 35
G90, G91 . . . . . . . . . . . . . . . . . . . . . . . . 26
G96 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Geometrical functions . . . . . . . . . . .26, 27
Graphically programming . . . . . . . .32, 33
Groove milling . . . . . . . . . . . . . . . . . . . . 41
Grooves . . . . . . . . . . . . . . . . . . . . . . . . . 74
H
Help screen . . . . . . . . . . . . . . . . . . .59, 60
HSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
I
Inclined bed machine . . . . . . . . 22, 22, 28
Incremental dimensioning . . . . . . . . . . . 26
Incremental position measuring system 23
Individual drive . . . . . . . . . . . . . . . . . . . 13
Inner arc . . . . . . . . . . . . . . . . . . . . . . . . . 28
Inner turning . . . . . . . . . . . . . . . . . . . . . 40
Islands . . . . . . . . . . . . . . . . . . . . . . . . . . 58
L
Language input . . . . . . . . . . . . . . . . . . . 20
Lathe . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Leadscrew drive . . . . . . . . . . . . . . . . . . . 18
Limit gauge . . . . . . . . . . . . . . . . . . . . . . 78
Linear motor . . . . . . . . . . . . . . . . . . . . . 19
Linking . . . . . . . . . . . . . . . . . . . . . . 59, 60
Linking drilling patterns . . . . . . . . . . . . 59
Logic operation . . . . . . . . . . . . . . . . . . . 57
Longitudinal roughing . . . . . . . . . . . . . . 40
M
M3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
M30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Machine tools . . . . . . . . . . 12, 13, 13, 14
Machine zero . . . . . . . . . . . . . . . . . . . . . 23
Machining step . . . . . . . . . . . . . . . . . . . 52
Main drive . . . . . . . . . . . . . . . . . . . . 18, 19
Maudsley, Henry . . . . . . . . . . . . . . . . . . 12
Measuring . . . . . . . . . . . . . . . . . . . .78, 80
Measuring system . . . . . . . . . . . . . . . . . 18
Microprocessor . . . . . . . . . . . . . . . . . . . 16
Milled part . . . . . . . . . . . . . . . . 25, 26, 27
Milling . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Milling radius control . . . . . . . . . . . . . . 35
Milling tool . . . . . . . . . . . . . . . . . . . . . . 34
MIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Modules . . . . . . . . . . . . . . . . . . . . . . . . . 13
Motors . . . . . . . . . . . . . . . . . . . . . . . . . . 19
N
NC program . . . . . . . . . . . . . . . 11, 19, 30
Nurbs interpolation . . . . . . . . . . . . . . . . 17
O
Outer arc . . . . . . . . . . . . . . . . . . . . . . . . 28
P
PCD . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Plunge strategies . . . . . . . . . . . . . . . . . . 54
Pockets . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Point-to-point and path control . . . . . . . 16
Programming interface . . . . . . . . . . . . . 17
Punched tape . . . . . . . . . . . . . . . . . . . . . 20
Pythagoras . . . . . . . . . . . . . . . . . . . . . . . 30
R
Rapid traverse . . . . . . . . . . . . . . . . . . . . 24
Reference point . . . . . . . . . . . . . . . . . . . 23
Reference points . . . . . . . . . . . . . . . . . . 23
Relay technology . . . . . . . . . . . . . . . . . . 16
84
Repeat accuracy . . . . . . . . . . . . . . . . . . . . 8
Replacement tools . . . . . . . . . . . . . . . . . 52
Residual material . . . . . . . . . . . . . . . 59, 72
Rotation . . . . . . . . . . . . . . . . . . . . . . 42, 43
Roughing . . . . . . . . . . . . . . . . . . . . . 40, 41
Rounding-off . . . . . . . . . . . . . . . . . . 32, 33
S
S address . . . . . . . . . . . . . . . . . . . . . 21, 42
Semiconductor memory . . . . . . . . . . . . 16
ShopMill . . . . . . . . . . . 17, 33, 50, 51, 52
ShopTurn . . . . . . . . . . . . . . 17, 32, 32, 64
Siemens, Werner von . . . . . . . . . . . . . . 19
Simulation . . . . . . . . . . . . . 56, 57, 58, 61
Sinter materials . . . . . . . . . . . . . . . . . . . 36
SINUMERIK . . . . . . . . . . . . . . . . . . 16, 17
Speed . . . . . . . . . . . . . . . . . 19, 42, 42, 43
Spindle lathe . . . . . . . . . . . . . . . . . . . . . 12
Steam engine . . . . . . . . . . . . . . . . . . . . . 12
Straight lines . . . . . . . . . . . . . . . . . . 26, 27
Surface quality . . . . . . . . . . . . . . . . . 10, 47
T
T address . . . . . . . . . . . . . . . . . . . . . . . . 21
Tangential function . . . . . . . . . . . . . . . . 26
Technical drawing . . . . . . . . . . . . . . . . . 10
Technological values . . . . . . . . . . . . . . . 52
Titanium carbide . . . . . . . . . . . . . . . . . . 37
Tolerance-plug gauge . . . . . . . . . . . . . . 80
Tool grinding machine . . . . . . . . . . . . . 81
Tool life monitoring . . . . . . . . . . . . . . . 52
Tool list . . . . . . . . . . . . . . . . . . . . . . 52, 66
Tool manufacturer . . . . . . . . . . . . . . . . . 37
Tool paths . . . . . . . . . . . . . . . . . . . . 34, 35
Tool steels . . . . . . . . . . . . . . . . . . . . . . . 36
Tools . . . . . . . . . . . . . . . . . . . . . . . . 36, 37
Transmission belts . . . . . . . . . . . . . . . . . 13
Tungsten carbide . . . . . . . . . . . . . . . . . . 37
Turned part . . . . . . . . . . . . . . . 25, 26, 27
Turning . . . . . . . . . . . . . . . . . . . . . . . . . 40
Turning tool . . . . . . . . . . . . . . . . . . . . . . 34
Turnplates . . . . . . . . . . . . . . . . . . . . 37, 39
W
Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Watt, James . . . . . . . . . . . . . . . . . . . . . . 12
Work plan . . . . . . . . . . . . . . . . . . . . . . . 57
Workpiece programming . . . . . . . . . . . . 16
Workpiece zero . . . . . . . . . . . . . . . . . . . 23
85
Diagrams/Photographs
We would like to thank the following companies and institutions, who provided us with
the photographs on the following pages.
BBoehringer, Göppingen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Bridgeport, Weiterstadt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
DDeutsches Museum, München . . . . . . . . . . . . . . . . . . . . . . . . . . .12, 13, 14
Deutsches Werkzeugmuseum/Historisches Zentrum, Remscheid 12, 13, 14
DMG, Bielefeld . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
HHanser-Verlag, München . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Hochschuldidaktisches Zentrum der RWTH Aachen . . . . . . . . . . . . . . . . 10
IIndex, Esslingen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Iscar, Ettlingen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36, 38, 39, 40, 41
KKlingelnberg, Hückeswagen . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10, 11, 81
Konradin-Verlag / INDUSTRIE Anzeiger, Leinfelden-Echterdingen . . . 19
LLaboratorium für Werkzeugmaschinen und Betriebslehre
der RWTH Aachen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7, 20
MMercedes-Benz Lenkungen GmbH, Düsseldorf . . . . . . . . . . . . . .10, 11, 81
NNC-Verlag, Hannover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
SSandvik, Düsseldorf . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36, 38, 39, 40, 41
Seco, Düsseldorf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36, 38, 39, 40, 41
VVerlag Europa-Lehrmittel, Haan-Gruiten . . . . . . . . . . . . . . . . . . . . . . . . . 39
