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FANUC Series 30i/300i/300is-MODEL A. Machining Center System. User's manual - page 105

22.5-AXIS MACHINING FUNCTION

PROGRAMMING

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- Tool behavior at startup and cancellation

When tool center point control is started (G43.4/G43.5) or canceled

(G49), the tool moves by a tool offset value.

Compensation vector calculation is performed only at the end of a
block.

- Current position display during tool center point control

During tool center point control, the position of the control point

(rotation center of the tool rotation axis) is displayed as the machine
coordinate.

When bit 5 (WKP) of parameter No.19696 is 0, whether to use

absolute or relative coordinates can be selected using bit 2 (DET) of
parameter No.19608.

If bit 2 (DET) of parameter No.19608 is 0, the position of the tool

center point on the programming coordinate system is displayed.

If bit 2 (DET) of parameter No.19608 is 1, the position of the tool

center point in the workpiece coordinate system is displayed.

- Tool offset

If tool offsets are used based on tool numbers, tool center point

control is carried out using the tool length compensation value
corresponding to the relevant tool number (T code).

If tool life management is used, tool center point control is carried out

using the tool length compensation value corresponding to the tool in
use.

- Function for placing priority on the path rather than on speed

If, in a block specifying a movement on a rotary axis, a high speed
(speed command or rapid traverse rate) is specified or the travel
distance on the rotary axis is larger than the travel distance of the tool
center point, an excessive path deviation can occur in the middle of
the block when a movement is made by the specified speed.
In such a case, priority can be placed on the path instead of the speed
so that the speed can be automatically lowered to prevent a deviation
from the path.

This function is enabled by setting bit 6 (CRS) of parameter No.
19746 to 1.
Set a maximum allowable path deviation in parameter No. 19751 (for
rapid traverse) or in parameter No. 19751 (for cutting feed).
When 0 is set as a maximum allowable path deviation, the
specification of the minimum unit of setting data of the parameter is
assumed.
When a negative value is set, the function for placing priority on the
path is disabled.

When a judgment is made to lower the speed, the speed of the entire
block is lowered.
As a result of speed reduction, the path error may be smaller than a
parameter-set value due to a calculation error.

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- Canned cycle during tool center point control

When bit 5 (TFA) of parameter No. 5105 is set to 1, if a canned cycle
being subjected to tool center point control is performed when the
position of the rotation axis that determines the tool axis direction is
not

n (n=0, 1, 2...) on the workpiece coordinate system, alarm

PS5424 (invalid tool axis direction) occurs.

CAUTION

A canned cycle being subjected to tool center point
control operates in the direction of the program
coordinate system. It does not always operates in
the current tool axis direction.
Be extremely careful about programming.

- Tool retract and recover during tool center point control

A tool retract and recover operation can be performed during tool
center point control. A retract operation is performed in the tool axis
direction by setting a tool axis direction retract amount in parameter
No. 11261.
This function is enabled on a machine of head rotation type.
For tool retract and recover operation, refer to "TOOL RETRACT
AND RECOVER" in Part for Operation.

Tool axis direction retract operation is enabled under the following
conditions:
1. The G10.6 command is singly executed (no axis address is

specified in the block specifying G10.6).

2. Bit 2 (RPS) of parameter No. 7040 is set to 1.
3. Tool center point control or workpiece setting error

compensation are being exercised. (However, bit 0 (RCM) of
parameter No. 11200 is set to 1 to perform compensation in the
tool direction.)

4.  A nonzero value is set in parameter No. 11261.

If the tool retract signal TRESC is set to 1 under the conditions above,
a retract operation is performed in the tool axis direction.    Parameter
No. 11261 is used to specify a retract amount.    A retract operation is
performed using the value of parameter No. 11261 as an incremental
retract amount.

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：

Position where tool retract switch is on

：

Retract position

：

Retract position by manual operation

：

Retract path (tool axis direction)

：

Manual operation (retract path)

：

Recover path

：

Repositioning

Parameter No.11261

If the tool retract signal TRESC is set to 1 during tool center point
control when the tool axis direction retract conditions mentioned
above are not satisfied, a retract operation of the conventional type is
performed. In such a case, specify the tool center point retract
position in a G10.6 block.

G10.6 alone

G10.6 X_ Y_ Z_

Bit 2 (RPS) of parameter No.7040 = 1

= 0

Parameter No.11261

≠

0.0

= 0.0

Tool axis direction retract

Conventional retract

(Parameter No. 7041)

Retract operation is not

performed.

Conventional

retract

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- Angle of the rotary axis for type 2 (when the movement range is not specified)

When the direction of the tool is specified by I, J, K, Q for type 2,
more than two pairs of "computed angles" of the rotary axes usually
exist.
The "computed angle" is the candidate angle at which the rotary axis
is to be controlled in the specified tool axis direction.
The "output angle" is determined from the "computed angle" based on
the "output judgment conditions" described below.

The following descriptions assume that there is no movement range
specification (parameter No.19741 - No.19744 = 0).

"Output judgment conditions"

Tool rotation type or table rotation type machine

<1> The "output angles" are represented by the computed rotary axis

angle pair whose master axis (first rotary axis) moving angle is
smaller.

↓

When the master axis moving angle is the same

↓

<2> The "output angles" are represented by the computed rotary axis

angle pair whose slave axis (second rotary axis) moving angle is
smaller.

↓

When the slave axis moving angle is the same

↓

<3> The "output angles" are represented by the computed rotary axis

angle pair whose master axis (first rotary axis) angle is nearer to 0
degree (multiple of 360 degrees).

↓

When the master axis angle is equally near to 0 degree

↓

<4> The "output angles" are represented by the computed rotary axis

angle pair whose slave axis (second rotary axis) angle is nearer to 0
degree (multiple of 360 degrees).

Composite type machine

<1> The "output angles" are represented by the computed rotary axis

angle pair whose table (second rotary axis) moving angle is smaller.

↓

When the table moving angle is the same

↓

<2> The "output angles" are represented by the computed rotary axis

angle pair whose tool (first rotary axis) moving angle is smaller.

↓

When the tool moving angle is the same

↓

<3> The "output angles" are represented by the computed rotary axis

angle pair whose table (second rotary axis) angle is nearer to 0
degree (multiple of 360 degrees).

↓

When the table angle is equally near to 0 degree

↓

<4> The "output angles" are represented by the computed rotary axis

angle pair whose tool (first rotary axis) angle is nearer to 0 degree
(multiple of 360 degrees).

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The process of judging whether the moving angle is smaller or larger
as the output judgement condition is called "movement judgement."
When bit 5 (PRI) of parameter No.19608 is 1, the movement
judgements for the first rotary axis and second rotary axis are made in
reverse order.

The "movement judgement" process is explained below.
When the "computed angle" is within the range between 0 and 360
degrees, it is called the "basic computed angle."
Usually, two pairs of "basic computed angles" exist.
For example, assume that a tool rotation type or table rotation type
machine has rotary axis A (master) and rotary axis B (slave) and that
there are two pairs of basic computed angles as follows:
(A

1 degree; B

1 degree)

2 degrees; B

2 degrees) where

≤

The "computed angle" is obtained from either of the following
expressions: "basic computed angle" + 360 degrees

N or "basic

computed angle" - 360 degrees

The current position of rotary axis A (master) is PA, and that of rotary
axis B (slave) is 0 degree.
Based on the PA angle, the "movement judgement" process is done as
follows (when bit 5 (PRI) of parameter No.19608 is 0).

-360

(N + 1) degrees

1 - 360

-360

N degrees

2 - 360

(N + 1)

1 - 360

(N - 1)

(*1)

0 degree

360 degrees

2 - 360

1 + 360

(*2)

360

(N + 1) degrees

1 + 360

360

N degrees

2 + 360

(N - 1)

1 + 360

(N + 1)

(*3)

•

Computed angle A

"Movement judgment"

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When the PA angle is (*1):
The output angle is: (A

2 - 360

(N + 1) degrees; B

2 degrees).

Namely,

2 - 360

(N + 1) degrees is adopted that is nearer to the

computed angle of A, and

2, which is the same group as

2, is

adopted as the computed angle of B.

When the PA angle is (*2):
The output angle is: (A

1 degrees; B

1 degrees).

Namely,

1 degrees is adopted that is nearer to the computed angle of

A, and

1, which is the same group as

1, is adopted as the computed

angle of B.

When the PA angle is (*3):
The output angle is: (A

+ 360

N degrees; B

2 degrees).

Namely,

2 + 360

N degrees is adopted that is nearer to the

computed angle of A, and

2, which is the same group as

2. is

adopted as the computed angle of B.

When the moving angle of rotary axis A (master) is the same, a
"movement judgement" is made for rotary axis B (slave) according to
the "output judgment conditions."
If the "output angle" of rotary axis A is determined by the "movement
judgement" for rotary axis A, the computed angle representing the
"smaller moving angle" is adopted as the "output angle" of rotary axis
B.
Similarly, if the "output angle" of rotary axis B is determined by the
"movement judgement" for rotary axis B, the computed angle
representing the "smaller moving angle" is adopted as the "output
angle" of rotary axis A.

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The "output angle" is explained below using a tool rotation type
machine as an example.
This example illustrates a machine having a "BC type tool axis Z."

C-axis: 1st rotation axis (master)

B-axis: 2nd rotation axis

(

)

Fig. 22.1 (h) BC type tool axis Z

The following two pairs of "computed basic angles" exist that direct
the tool axis toward the + X axis direction.
(B 90 degrees; C 180 degrees)
(B 270 degrees; C 0 degree)

<1> When the current rotary axis angles are (B -70 degrees; C 30

degrees)

The "output angles" are (B -90 degrees; C 0 degree).
0 degree is adopted because it is nearer to the current

position (30 degrees) of the C-axis that is the master axis.
For the B-axis, 270 degrees is adopted which is the same
group. However, this is changed to -90 degrees (270
degrees - 360 degrees) which is the nearest to the current
position of the B-axis (-70 degrees).

<2> When the current rotary axis angles are (B 80 degrees; C 500

degrees)

The "output angles" are (B 90 degrees; C 540 degrees).
540 degrees (180 degrees

360 degrees) is adopted because

it is nearer to the current position (500 degrees) of the C-axis
that is the master axis. For the B-axis, 90 degrees is
adopted which is the same group.

<3> When the current rotary axis angles are (B 60 degrees; C 90

degrees)

The "output angles" are (B 90 degrees; C 180 degrees).
Since the two candidates are equally near to the current

position (90 degrees) of the C-axis that is the master axis, a
judgment is made based on the current position of the B-axis.
90 degrees is adopted because it is nearer to the current
position (60 degrees) of the B-axis that is the slave axis.
For the C-axis, 180 degrees is adopted which is the same
group.

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<4> When the current rotary axis angles are (B 180 degrees; C 90

degrees)

The "output angles" are (B 270 degrees; C 0 degree).
Since the two candidates are equally near to the current

position (90 degrees) of the C-axis that is the master axis, a
judgment is made based on the current position of the B-axis.
In this case, however, the two candidates are also equally
near to the current position of the B-axis (180 degrees).
Therefore, the candidate is adopted in which the C-axis
(master axis) is nearer to 0 degree.

That is, the pair is adopted whose C axis angle is 0 degree

and whose B axis angle is 270 degrees.

When the slave axis angle is 0 degree, the direction of the tool axis
becomes fixed regardless of the master axis angle.
In that case, the master axis does not move from the current angle.

An explanation is shown below using a machine having a "BC type
tool axis Z" as an example.

Fig. 22.1 (i) BC type tool axis Z

When the current rotary axis angles are (B 45 degrees; C 90 degrees),
the "output angles" are (B 0 degree; C 90 degrees).

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