HEIDENHAIN IK 5294 - Manual (Page 174)

154 QC5200 Series User’s Guide
LMC
The LMC tolerance entry screens for arcs and circles are identi-
cal, 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. How-
ever, if a bore is exactly the LMC size, no position bo-
nus is generated and the bore must be located exactly as
specified. When a Reference feature is used and found
to have a tolerance surplus, it also generates a position
tolerance bonus for the bore.
Select the feature type as a Boss or a Bore, enter the
acceptable position Tol Zone value, enter the nominal
radius value, select a Reference feature if required and
then click OK. Reference features of LMC are dis-
cussed in Appendix C: Tolerances.
Runout
Runout tolerances can be applied to arcs and circles.
The tolerance entry screens are identical, and are used to
specify the acceptable deviation from a circle around the
center of the Reference feature axis.
Enter the acceptable position deviation value into the Tol
Zone data field provided and then click OK.
Minimum material within
a bore
Minimum
material on a
boss
6 Tolerancing OE.indd 10 5/9/2005 9:51:53 AM