HEIDENHAIN TNC 320 - RECTANGULAR POCKET (Cycle 251, DIN;ISO: G251); Cycle Run

RECTANGULAR POCKET (Cycle 251, DIN/ISO: G251) 5.2
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HEIDENHAIN | TNC 320 | User’s manual for cycle programming | 9/2016
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5.2 RECTANGULAR POCKET (Cycle 251,
DIN/ISO: G251)
Cycle run
Use Cycle 251 RECTANGULAR POCKET to completely machine
rectangular pockets. Depending on the cycle parameters, the
following machining alternatives are available:
Complete machining: Roughing, floor finishing, side finishing
Only roughing
Only floor finishing and side finishing
Only floor finishing
Only side finishing
Roughing
1 The tool plunges the workpiece at the pocket center and
advances to the first plunging depth. Specify the plunging
strategy with parameter Q366.
2 The TNC roughs out the pocket from the inside out, taking
the path overlap (parameter Q370) and the finishing allowance
(parameters Q368 and Q369) into account.
3 At the end of the roughing operation, the TNC moves the tool
tangentially away from the pocket wall, then moves by the set-
up clearance above the current pecking depth and returns from
there at rapid traverse to the pocket center.
4 This process is repeated until the programmed pocket depth is
reached.
Finishing
5 If finishing allowances have been defined, the TNC plunges and
then approaches the contour. The approach movement occurs
on a radius in order to ensure that a gentle approach is possible.
The TNC first finishes the pocket walls, in multiple infeeds if so
specified.
6 Then the TNC finishes the floor of the pocket from the inside
out. The pocket floor is approached tangentially.