G73 / G83 Peck Drilling Reposition Location - Mach4

Symptoms

  • The control descends too far on a rapid reposition and breaks drill bits.
  • High-speed peck drilling needs a different retract distance than the system default.

Solution

Mach4 has two machine parameters that affect the reposition behavior with regards to peck drilling.

In versions of Mach 4 older than 4.2.0.3779 (prior to 2018-05-04) these were pound variables.
Mach 4 Machine Parameters were added at that time, moving some system variables and pound variables to the machine parameter space.
Setting a pound variable in G code is done this way: #5114=500

SV_HSP_CLEARANCE / #5114

High Speed Peck drilling cycle (G73) rapid retract clearance.
(integer specifying .0001" or .001mm increments, depending on machine units)

This parameter is how far above the bottom of each peck to command a rapid movement to before descending for the next peck.

g73-100.png

G code Examples

Machine units are inches
G10 L50
N5114 R250 (0.0250")
G11

G73 X0 Y0 Z-2 R.5 Q.5 F20
Machine units are millimeters
G10 L50
N5114 R600 (0.60mm)
G11

G73 X0 Y0 Z-50.8 R12.7 Q12.7 F500

SV_FRP_CLEARANCE / #5115

Full Retract Peck drilling cycle (G73, G83) rapid clearance before feed starts.
(integer specifying .0001" or .001mm increments, depending on machine machine units)

This parameter is how far above the bottom of the (previous peck) to command a rapid movement to before starting feed rate moves descending for the next peck.

g73-750.png

For the G83 Full Retract Peck Drilling cycle, the behavior is the same, except every rapid retract goes to the retract plane (R parameter). The HSP parameter does not affect G83 behavior.

g83-peck-drilling.png

G code Examples

Machine units are inches
G10 L50
N5115 R100 (0.01")
G11

G83 X0 Y0 Z-2 R.5 Q.5 F20
G10 L50
N5115 R100 (0.01")
G11

G73 X0 Y0 Z-2 R.5 Q.5 F20
Machine units are millimeters
G10 L50
N5115 R250 (0.25mm)
G11

G83 X0 Y0 Z-50.8 R12.7 Q12.7 F500 
G10 L50
N5115 R100 (0.01")
G11

G73 X0 Y0 Z-50.8 R12.7 Q12.7 F500

Keywords: 14513

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