Radial Recessing Extended (Cycle 842, Din/Iso: G842); Application; Roughing Cycle Run - HEIDENHAIN TNC 640 User Manual

12
12.17 RADIAL RECESSING EXTENDED
(Cycle 842, DIN/ISO: G842)

Application

This cycle enables you to recess right-angled slots in longitudinal
direction. With recess turning, a recessing traverse to plunging
depth and then a roughing traverse is alternatively machined. The
machining process thus requires a minimum of retraction and
infeed movements. Expanded scope of function:
You can insert a chamfer or curve at the contour start and
contour end.
In the cycle you can define angles for the side walls of the slot
You can insert radii in the contour edges
You can use the cycle either for roughing, finishing or complete
machining. Turning is run paraxially with roughing.
The cycle can be used for inside and outside machining. If the start
diameter Q491 is larger than the end diameter Q493, the cycle
runs outside machining. If the start diameter Q491 is less than the
end diameter Q493, the cycle runs inside machining.

Roughing cycle run

The TNC uses the tool position as cycle starting point when a cycle
is called. If the Z coordinate of the starting point is less than Q491
DIAMETER AT CONTOUR START, the TNC positions the tool in the X
coordinate to Q491 and begins the cycle there.
1 From the cycle starting point, the TNC recesses until the first
plunging depth.
2 The TNC cuts the area between the starting position and the
end point in longitudinal direction at the defined feed rate Q478.
3 If the input parameter
elements are machined at the programmed feed rate for
plunging.
4 If only one machining direction Q507=1 was specified in
the cycle, the TNC retracts the tool by the set-up clearance,
positions the tool back at rapid traverse and approaches the
contour again with the defined feed rate. With machining
direction Q507=0, infeed is on both sides.
5 The tool recesses to the next plunging depth.
6 The TNC repeats this process (2 to 4) until the slot depth is
reached.
7 The TNC returns the tool to set-up clearance and machines a
recessing traverse on both side walls.
8 The TNC positions the tool back at rapid traverse to the cycle
starting point.
418
Q488 is defined in the cycle, plunging
Cycles: Turning | RADIAL RECESSING EXTENDED
(Cycle 842, DIN/ISO: G842)
HEIDENHAIN | User's manual for cycle programming | 10/2017