I am trying to setup my mill to use a Stm JSN7 tapping head. It self feeds for 0.14" after the feed stops, then goes into neutral. I set up the tool using Axial Travel at 0.14" this is the Gcode generated. for a hole tapped to 0.500" deep

N0010 (Filename: Taig CNC Lead Screw Nut.tap)

N0020 (Post processor: Mach3.scpost)

N0030 (Date:30/05/2014 Time:12:17:02)

N0040 G20 (Units: Inches)

N0050 G40 G90 G91.1

N0060 F1

N0070 (Part: Taig CNC Lead Screw Nut)

N0080 (Operation: Tap, 10-32_THREADS, T12: Tapping head #10-28 tap, 0.5 in Deep)

N0090 S500 G00 Z3.0000

N0100 X0.0000 Y0.0000

N0110 (Tapping head #10-28 tap)

N0120 T12 M06

N0130 G43 H12

N0140 G00 Z0.1250

N0150 S1000 M03

N0160 M49

N0170 G95

N0180 X-0.4970 Y-0.7263

N0190 Z0.0394

N0200 G01 Z-0.500 F0.0357

N0210 Z-0.360 F393.7008

N0220 Z0.179 F0.0714

N0230 G00 Z0.1250

N0240 X-1.1220 Y-0.5388

N0250 Z0.0394

N0260 G01 Z-0.500 F0.0357

N0270 Z-0.360 F393.7008

N0280 Z0.179 F0.0714

N0290 G00 Z0.1250

Then on to the next hole.

On line 200, it gives the feed down to z -0.500, then on line 210 tries to jump back to z -0.360 at an extreme feed rate then on line 220retract at the 2x retract speed to Z 0.179. Where does the z0.179 come from?

It would seem that feeding to z-0.360 and then a pause of four index pluses then the 2x retract would be a better method. I worry that the quick jerk back from depth might stall my z axis stepper and if this were to happen, the tap would continue to self feed.to z -0.614"

This is my first attempt to CNC feed the tapping head.and I want to understand what is going on before commenting a tap to metal.

Don

**. ,.**_

Posted by: Don@Campbell-Gemstones.com

Unsubscribe (<sheetcam-unsubscribe@yahoogroups.com>?subject=Unsubscribe) • Terms of Use

**, .,**_