Siemens sinumerik 808d Programming And Operating Manual page 165

MID (infeed depth)
The MID parameter is used to define the maximum possible infeed depth for the roughing
process.
The cycle will automatically calculate the current infeed depth used for roughing.
With contours containing relief cut elements, the roughing process is divided by the cycle
into individual roughing sections. The cycle calculates a new current infeed depth for each
roughing section. This infeed depth is always between the programmed infeed depth and the
half of its value. The number of required roughing steps is determined on the basis of the
total depth of a roughing section and of the programmed maximum infeed depth to which the
total depth to be machined is distributed equally. This provides optimum cutting conditions.
For roughing this contour, the machining steps shown in the illustration result.
Machining section 1 has a total depth of 39 mm. If the maximum infeed depth is 5 mm, eight
roughing cuts are required. These are carried out with an infeed of 4.875 mm.
In machining step 2, 8 roughing steps, too, are carried out with an infeed of 4.5 mm each
(total difference 36 mm).
In machining step 3, two roughing passes are carried out with a current infeed of 3.5 (total
difference 7 mm).
FAL, FALZ and FALX (finishing allowance)
A finishing allowance for roughing can be specified either using the parameters FALZ and
FALX if you want to specify different finishing allowances axis-specifically or via the
parameter FAL for a finishing allowance that follows the contour. In this case, this value is
taken into account in both axes as a finishing allowance.
Turning Part 2: Programming (Siemens instructions)
Programming and Operating Manual, 05/2012, 6FC5398-5DP10-0BA0
2.5 Turning cycles
defined as a section in the
calling program, which starts
from the block containing label
START to the block containing
label END.
Cycles
165