HEIDENHAIN TNC 620 User Manual page 241

Fixed Cycles: Contour Pocket | TROCHOIDAL SLOT (Cycle 275, DIN/ISO: G275, software option 19)
Roughing with open slots
The contour description of an open slot must always start with an
approach block (APPR).
1 Following the positioning logic, the tool moves to the starting
point of the machining operation as defined by the parameters
in the APPR block and positions there perpendicular to the first
plunging depth.
2 The TNC roughs the slot in circular motions to the contour end
point. During the circular motion the TNC moves the tool in
machining direction by an infeed you can define (Q436). Define
climb or up-cut of the circular motion in parameter Q351.
3 At the contour end point, the TNC moves the tool to clearance
height and returns to the starting point of the contour description.
4 This process is repeated until the programmed slot depth is
reached.
Finishing with open slots
5 Inasmuch as a finishing allowance is defined, the TNC finishes
the slot walls, in multiple infeeds if so specified. Starting from the
defined starting point of the APPR block, the TNC approaches the
slot wall. Climb or up-cut are taken into consideration.
HEIDENHAIN | TNC 620 | User's manual for cycle programming | 10/2017
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