HEIDENHAIN ND 730 User Manual v.1
User’s Manual
Position Display Units
for Lathes
6/ 99
Position display
(ND 730 only two axes)
• Select coordinate axis
(ND 730 only X and Z)
• Select axis-based operating parameters
Status display:
SET = Set datum
REF = Blinking:
Traverse reference
marks
Lighting:
Reference marks have
been traversed
= Distance-to-go
∆
Inch= Inch display
SCL = Scaling factor
R = Radius/diameter
display
T = Tool selected
HEIDENHAIN
••
• Tool compensation
••
• Scroll backwards in special functions
list
• Scroll backwards in parameter list
Numerical input
• Change sign
• Call last dialog
• In parameter list:
Change parameter
• Confirm entry
• Scroll forwards in parameter list
Select radius/diameter display
in X axis
• Select special functions
• Scroll forwards in special
functions list
• Abort entry
• Reset operating mode
• Reset selected axis to zero
(if activated via P 80)
• Select parameter:
CL plus two-digit number
This manual is for ND display units with the following
software numbers or higher:
Part I Operating Instructions
ND 730 for two axes AA00
ND 770 for three axes AA00
About this manual!
This manual is divided into two parts:
Part I: Operating Instructions:
• Fundamentals of positioning
• ND functions
Part II: Installation and Specifications:
• Mounting the display unit on the machine
• Description of operating parameters
Fundamentals 4
Switch-On, Reference-Mark Traverse 10
Selecting Radius or Diameter Display 11
Separate Value/Sum Display
(only ND 770) 12
Datum Setting 13
Setting the absolute workpiece datum 13
Entering tool data (relative datums) 14
Holding Positions 15
Moving the Axes with Distance-To-Go 17
Taper Calculator 19
Error Messages 23
Part II
Installation and Specifications 25
Part I Operating Instructions
3
Fundamentals
You can skip this chapter if you are already familiar with
coordinate systems, incremental and absolute dimensions,
nominal positions, actual positions and distance-to-go!
Coordinate system
Fundamentals
To describe the geometry of a workpiece, a rectangular or
coordinate system is used. The Cartesian coordinate system consists
of three mutually perpendicular axes X, Y and Z. The point of
intersection of these axes is called the datum or origin of the
coordinate system.
Think of the axes as scales with divisions (usually in millimeters) that
allow us to fix points in space referenced to the datum.
To determine positions on a workpiece, the coordinate system is
“laid” onto the workpiece.
With lathe work (i.e. rotationally symmetrical workpieces), the Z axis
moves along the axis of rotation, and the X axis moves in the direction
of the radius or diameter. The Y axis can be disregarded since it would
always have the same values as the X axis.
Cartesian
+Y
+Z
Graduation
+X
1)
–X
–Z
Datum or
origin
–Y
X
Z
1)
Named in honor of the French mathematician and philosopher
4
René Descartes (1596 to 1650)
Cross slide, saddle and top slide
Z
Z
O
X
+Z
+X
+Z
O
On conventional lathes, the tool is mounted on a slide that moves in
the direction of the X axis (the cross slide) and in the direction of the Z
axis (the saddle).
Most lathes have a top slide above the saddle. The top slide moves in
Z axis direction and is designated Zo.
Fundamentals
5
Datum setting
The workpiece drawing is used as the basis for machining the
workpiece. To enable the dimensions in the drawing to be converted
into traverse distances of machine axes X and Z, each drawing
dimension requires a datum or reference point on the workpiece
(since a position can only be defined in relationship to another
position).
Fundamentals
The workpiece drawing always indicates one absolute datum (the
datum for absolute dimensions). However, it may contain additional,
relative datums.
In the context of a numerical position display unit,
datum setting
means bringing the workpiece and the tool into a defined position in
relation to each other and then setting the axis displays to the value
which corresponds to that position. This establishes a fixed
relationship between the actual positions of the axes and the
displayed positions.
With the ND, you can set one absolute datum point and as many as
9 relative datum points (tool datums), and store them in nonvolatile
memory.
3530
Relative
datum
Absolute
datum
Z
5
10
X
6
Tool datums (tool compensation)
Your display unit should show you the absolute position of the
workpiece, regardless of the length and shape of the particular tool
being used. For this reason you must determine the tool data and
enter it. First touch the workpiece with the cutting edge of the tool
and then enter the associated display value for that position.
You can enter tool data for up to 9 tools. When you have set the
absolute workpiece datum for a new workpiece, all tool data (= relative
datum points) are referenced to the new workpiece datum.
Fundamentals
Nominal position, actual position and distance-to-go
The positions to which the tool is to move are called the nominal
S
positions (
given moment is called the actual position (I).
The distance from the nominal position to the actual position is called
the distance-to-go (
Sign for distance-to-go
When you are using the distance-to-go display, the nominal position
becomes the relative datum (display value 0). The distance-to-go is
therefore negative when you move in the positive axis direction, and
positive when you move in the negative axis direction.
). The position at which the tool is actually located at any
).
R
R
T1
T2
IS
T3
Z
X
7
Absolute workpiece positions
Each position on the workpiece is uniquely defined by its absolute
coordinates.
Example Absolute coordinates of position
:
1
X = 5 mm
Z = –35 mm
Fundamentals
If you are working according to a workpiece drawing with absolute
dimensions, you are moving the tool to the coordinates.
Relative workpiece positions
A position can also be defined relative to the previous nominal
position. The datum for the dimension is then located at the previous
nominal position. Such coordinates are termed relative coordinates or
chain dimensions. Incremental coordinates are indicated by a
preceding I.
65
35
0
Z
1
5
15
X
Example Relative coordinate of position referenced to
position
1
:
2
3530
IX = 10 mm
IZ = –30 mm
If you are working according to a workpiece drawing with incremental
dimensions, you are moving the tool by the dimensions.
Sign for incremental dimensioning
A relative dimension has a positive sign when the axis is moved in the
1
2
Z
5
10
X
positive direction, and a negative sign when it is moved in the
8
negative direction.
Position encoders
The position encoders on the machine convert the movements of the
machine axes into electrical signals. The ND display unit evaluates
these signals, determines the actual position of the machine axes and
displays the position as a numerical value.
If the power is interrupted, the relationship between the machine axis
positions and the calculated actual positions is lost. The reference
marks on the position encoders and the REF reference mark
evaluation feature enable the ND to quickly re-establish this
relationship again when the power is restored.
Reference marks
The scales of the position encoders contain one or more reference
marks. When a reference mark is crossed over, a signal is generated
identifying that position as a reference point (scale datum = machine
datum).
When this reference mark is crossed over, the ND's reference mark
evaluation feature restores the relationship between axis slide
positions and display values as you last defined it by setting the
datum. If the linear encoders have distance-coded reference marks,
you need only move the machine axes a maximum of 20 mm to
restore the datum.
Workpiece
Scale in linear
encoder
Z
Fundamentals
Encoder
Distance-coded
reference marks
Reference mark
9
Switch-On, Reference-Mark Traverse
0 è 1
ENT ... CL
ENT
Crossing over the reference marks stores the last relationship
between axis slide positions and display values for all datum points in
nonvolatile memory.
Switch-On, Reference-Mark Traverse
Note that if you choose not to cross over the reference marks (by
clearing the dialog ENT ... CL with the CL key), this relationship will be
lost if the power is switched off or otherwise interrupted!
You must cross over the reference marks if you want to use
the multipoint axis error compensation function.
(See “Multipoint Axis Error Compensation”)
Turn on the power (switch located on rear panel).
REF is blinking in the status display.
Confirm reference-point traverse.
REF is now lighting. Decimal points are blinking.
Cross over the reference marks in all axes (in any
sequence). Each axis display becomes active when
its reference mark is crossed over.
10
Selecting Radius or Diameter Display
Your ND can display positions in the cross slide as a diameter or as a
radius. Drawings of lathe parts usually indicate diameters. When you
are turning the part, however, you infeed the tool in the cross slide
axis in radius values.
Example: Radius display position X = 20 mm
Diameter display position X = 40 mm
To switch the display:
Press
¬
Z
¯40
1
20
X
When radius display for the X axis is selected, R
When diameter display is selected, R
goes out.
X
lights up.
X
Selecting Radius or Diameter Display
11
Separate Value/Sum Display (ND 970 only)
Separate value display
In this mode the positions of the saddle and top slide are displayed
separately. The position displays are referenced to the datum points
that you set for the Zo and Z axes. When an axis slide moves, only the
position display for that axis changes.
Sum display
In this mode the position values of both axis slides are added together.
The sum display shows the absolute position of the tool, referenced to
the workpiece datum.
Z
40
Z
0 +10 +25
Z
Z
0
Example Separate value display: Z = +25.000 mm
Sum display: Z
The sum display will only show correct values if the actual
position values of both axis slides were correctly added and
entered (with sign) when setting the datum for the “sum.”
To switch the display
Separate Value/Sum Display (ND 770 only)
➤ Sum display: Press the keys Zo and Z at the same time.
➤ Separate value display: Press the key Zo.
When the ND 770 displays sums, the Zo display is switched
off.
12
Zo = +15.000 mm
= +40.000 mm
S
Z
0
Ð10
0 +15
Loading...