HEIDENHAIN ND 1300 OED and Crosshair Systems - Manual (Page 152)

134 QC-300 Series User’s Guide
LMC Circles and arcs
The LMC tolerance screens for circles and arcs 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
result 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 and Y axis and D (diam-
eter) data fields provided. Enter
the allowed Tol Dia (Tolerance
diameter) and feature diameter
limits into the Limit data fields as
+/- ranges or as absolute limits.
Touch the Limit data fields to
toggle between +/- ranges or ab-
solute limits.
Minimum material within
a bore
Minimum material on
a boss