HEIDENHAIN ND 1400 - Manual (Page 92)

78 QC-300 Series User’s Guide
LMC Circles, arcs and cylinders
The LMC tolerance screens for circles, arcs and
cylinders are identical, and are used to specify the
minimum material that can exist within a bore or on
the surface of a boss.
LMC tolerances can generate position bonuses as a re-
sult of size tolerance surpluses. For example, when the
size of a bore is smaller than LMC, but within the acceptable tolerance range, a position tolerance bonus
is generated for the bore and its acceptable location is given more flexibility. However, if a bore is within
the position tolerance diameter, no position bonus is generated and the bore must be located exactly as
specified.
Touch the Boss or Bore choice
field to specify the feature type as
a Boss or a Bore.
Enter the nominal values into the
X, Y and Z axis and D (diameter)
data fields provided. Enter the al-
lowed Tol Dia (Tolerance diam-
eter) and feature diameter limits
into the Limit data fields as +/-
ranges or as absolute limits.
Touch the Limit data fields to tog-
gle between +/- ranges or absolute
limits.
Minimum material within
a bore
Minimum material on
a boss