Inside contours, 1 8 mac h ining inf o rm ation – HEIDENHAIN CNC Pilot 4290 V7.1 User Manual
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HEIDENHAIN CNC PILOT 4290
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Inside contours
TURN PLUS machines continuous inside contours up to the transition
from the “deepest point” to a greater diameter. The end position for
drilling, roughing and finishing operations depends on:
Cutting limit, inside
Overhang length, inside ULI (machining parameter 4)
Prerequisite: The usable tool length must be sufficient for the
machining operation. If it is not, then this parameter defines the inside
machining operation. The following examples explain the principle.
Limits for internal machining operations
Predrilling: SBI limits the drilling operation.
Roughing: SBI or SU limit the roughing operation.
SU = basic length of roughing cut (sbl) + overhang length, inside
(ULI)
To avoid residual rings during the machining process, TURN PLUS
leaves an area of 5° in front of the roughing limit.
Finishing: sbl limits the finishing operation.
Roughing limit in front of cutting limit
Example 1: The roughing limit (SU) is located in front of the cutting
limit, inside (SBI).
Abbreviations
SBI: Cutting limit, inside
SU: Roughing limit (SU = sbl + ULI)
sbl: Basic length of roughing cut (“deepest” point of inside contour)
ULI: Overhang length, inside (machining parameter 4)
nbl: Usable tool length (tool parameter)