Universal drilling (cycle g203) – HEIDENHAIN iTNC 530 (340 49x-01) ISO programming User Manual

Page 256

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8 Programming: Cycles

8.3 Cy

cles f

o

r Dr

illing, T

a

pping and Thr

ead Milling

UNIVERSAL DRILLING (Cycle G203)

1

The TNC positions the tool in the tool axis at rapid traverse to the
input set-up clearance above the workpiece surface.

2

The tool drills to the first plunging depth at the programmed feed
rate F.

3

If you have programmed chip breaking, the tool then retracts by
the entered retraction value. If you are working without chip
breaking, the tool retracts at the retraction feed rate to set-up
clearance, remains there—if programmed—for the entered dwell
time, and advances again at rapid traverse to the set-up clearance
above the first PLUNGING DEPTH.

4

The tool then advances with another infeed at the programmed
feed rate. If programmed, the plunging depth is decreased after
each infeed by the decrement.

5

The TNC repeats this process (2 to 4) until the programmed total
hole depth is reached.

6

The tool remains at the hole bottom—if programmed—for the
entered dwell time to cut free, and then retracts to set-up
clearance at the retraction feed rate. If you have entered a 2nd set-
up clearance, the tool subsequently moves to that position in rapid
traverse.

Example: NC blocks

N110 G203 UNIVERSAL DRILLING

Q200=2

;SET-UP CLEARANCE

Q201=-20

;DEPTH

Q206=150

;FEED RATE FOR PLUNGING

Q202=5

;PLUNGING DEPTH

Q210=0

;DWELL TIME AT TOP

Q203=+20

;SURFACE COORDINATE

Q204=50

;2ND SET-UP CLEARANCE

Q212=0.2

;DECREMENT

Q213=3

;BREAKS

Q205=3

;MIN. PLUNGING DEPTH

Q211=0.25

;DWELL TIME AT DEPTH

Q208=500

;RETRACTION FEED RATE

Q256=0.2

;DIST. FOR CHIP BRKNG

X

Z

Q200

Q201

Q206

Q202

Q210

Q203

Q204

Q211

Q208

Before programming, note the following:

Program a positioning block for the starting point (hole
center) in the working plane with radius compensation
G40.

The algebraic sign for the cycle parameter DEPTH
determines the working direction. If you program
DEPTH = 0, the cycle will not be executed.

Enter in MP7441 bit 2 whether the TNC should output an
error message (bit 2=1) or not (bit 2=0) if a positive depth
is entered.

Danger of collision!

Keep in mind that the TNC reverses the calculation for pre-
positioning when a positive depth is entered. This
means that the tool moves at rapid traverse in the tool axis
at safety clearance below the workpiece surface!

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