Lenze ETC Motion Control User Manual

Page 100

CNC programming

G functions
G functions individual descriptions

3.2
3.2.2

100

EDSTCXN EN 2.0

If target values are missing, the corresponding circle start values are used.
The specification of a center is always interpreted as a relative specification
to the circle start point. Since there is always more than one circle center for
the radius programming from a mathematical point of view, it is not possible
to program a full circle in this circle determination mode. From the two
possible centers, a negative radius selects the one which results in the larger
arc. The combination of the DIN addresses of G2/G3, which are beyond the
necessary specifications, results in the following geometries:

a) Helix with cylinder surface

The linear axis which is positioned vertically to the selected plane must be
programmed. This specification results in a simultaneous linear
interpolation of the axis between the circle start point and the circle target
point. If an additional optional DIN address is not specified, then the helix
covers a maximum of 360

G17: Z
G18: Y
G19: X

By specifying the number (n) of additional full circles, the helix can be
extended to a maximum of (n+1)*360

G17: ZK
G18: YI
G19: XJ

b) Helix with cone surface

All the specifications under a) also apply here. However, a delta radius (D)
must also be programmed. The cone radius then opens (D>0) or closes (D<0)
evenly from the circle start point through to the circle target point.

G17: ZKD
G18: YID
G19: XJD

c) Spiral in the plane

All the specifications under b) are also needed here, however, without the
linear positioning.

G17: KD
G18: ID
G19: JD

When the preparatory function G112 has been executed previously, the
tangential correction of the rotation axis is possible, which is assigned to the
selected plane (default: G17: C, G18: B, G19: A). If G112 was programmed
with " Schlagzustellung der Rotationsachse " (Abrupt positioning of the
rotation axis), the start angle of the rotation axis can be specified under the
corresponding DIN addresses (A,B,C) for G2/G3. If the tangential correction
is not switched on, the target angle of the rotation axis can be programmed.
The rotation axis is then positioned linearly between the start and target
angle on the circular path.