G-co d e ca n n e d cy c l e S
Introduction
Canned cycles are used to simplify programming. They are used for repetitive
operations, such as drilling, tapping, and boring. The canned cycle is executed
every time an X and/or Y-axis motion is programmed.
Using Canned Cycles
The positioning of a canned cycle in the X and/or Y-axes can be done in either
absolute (G90) or incremental (G91). Incremental (G91) motion in a canned
cycle is often useful with a loop count (Lnn) which will repeat the canned cycle
operation that many times with each incremental X or Y move for the canned
cycle.
Example:
G81 G99 Z-0.5 R0.1 F6.5 (This will drill one hole at the present location)
G91 X-0.5625 L9 (This will drill 9 more holes .5625 equally spaced in the
minus direction)
If a canned cycle is dened without an X or Y and a loop count of 0 (L0), the
cycle will not be performed initially. The operation of the canned cycle will vary
according to whether incremental (G91) or absolute (G90) positioning is active.
Incremental motion in a canned cycle is often useful as a loop (L) count as it
can be used to repeat the operation with an incremental X or Y move between
each cycle.
Example:
X1.25 Y-0.75 (center location of bolt hole pattern)
G81 G99 Z-0.5 R0.1 F6.5 L0 (L0 on the G81 line will not drill a hole in the
bolt hole circle)
G70 I0.75 J10. L6 (6-hole bolt hole circle)
Once a canned cycle is commanded, that operation is done at every X-Y
position listed in a block. Some of the canned cycle numerical values can be
changed after the canned cycle is dened. The most important of these are the
R plane value and the Z depth value. If these are listed in a block with XY com-
mands, the XY move is done and all subsequent canned cycles are performed
with the new R or Z value.
The positioning of the X and Y-axes prior to a canned cycle is done with rapid
moves.
G98 and G99 change the way the canned cycles operate. When G98 is active,
the Z-axis will return to the initial start plane at the completion of each hole in
the canned cycle. This allows for positioning up and around areas of the part
and/or clamps and xtures.
When G99 is active, the Z-axis returns to the R (rapid) plane after each hole in
To Next Page
Loading...
