Need Help!- Higby Theading

[CHampshire]

OK guys I need some help here. I am attempting to do my first higby thread. I have done research on this site as well as a few others and have got the basics down. Let me give a few specs to get started.

Thread size 4 1/8x3 t.p.i ACME
Thread length is 1.25 long.
Using G76 cycle
Thread tool is .250 wide
Higby is .250 wide groove tool
Z zero is at end of part
Start point for the thread tool is z.333

What is the proper way to do this? Do I need to offset any of my tools when I set them or do I set them at Z0 like I normally would?

I understand the whole rpm/rapid determines the lead out and chord length of the chamfer. I have read that you offset the thread tool. I have read that you change the start point for the groove tool. I am confused and need some help as I can't waste another day trying to figure this out!

Thanks in advance for all suggestions!

[John_B]

I haven't done this alot, but last time I did it I just programmed the groove tool using the same threading macro - except the start and end were set to the start point of the first thread and the back side of it so the groove tool only went in long enough to take a bite and pulled out. I set the tool exactly as normal, no offsetting out or in.

Regards,
John

[CHampshire]

Figured I would fill everyone in that I got it figured out. All tools are set off Z zero with no offsets. Here is the code
N12T101(TOOL FLO ACME INSERT)
(M3 SPINDLE ROTATION)
G0G40G54G90G50S1000M41
G97S250M3
G0X4.3Z.333M8
X4.2Z.333
G76P010029Q0030R.001
G76X3.755Z-1.5P1750Q0050F.333
M9
G28U0M5
G0Z3
M01
N13T707(.250 WIDE TOOL FLO GROOVE FOR HIGBY)
G0G40G54G90G50S800M41
G97S130M3(RIGHT HAND)
G0X4.300Z.5M8
G76P010029Q0030R.001
G76X3.755Z-.333P1750Q0050F.333
M9
G28U0M5
G0Z3
M01
N14T606(LEFT HAND TOOL FLO,.250 WIDE INSERT)
G0G40G54G90G50S800M41
G97S130M4
G0Z-1.5M8
X4.300
Z-1.5X4.300
G76P010029Q0030R.001
G76X3.755Z-1.P1750Q0005F.333
M9
G28U0M5
G0Z3
N15T909(45 DEGREE TO CHAMFER THREADS)
G0G40G54G90G50S1000M41
G97S250M3
G0X4.3Z.333M8
X4.2Z.333
G76P010029Q0030R.001
G76X3.755Z-1.5P1750Q0050F.333
M9
G28U0M5
G0Z3
M30

Hope this helps someone in the future