g71 stock removal

hi all

g71 stock removal

I have seig kc4s cnc lathe it runs on a Chinese version of fanuc the manual is something else totally useless

iam trying to use g71 to machine from a 45 mm dia bar down to 28.5 dia by 28 in length in .5 cuts this is the code I have written as far as I understand it

idont understand how it knows what dia to start from the finish dia is in the code

t0101

g0x50z5 move to safe zone

g71u.5r4. depth of cut .5 retract 4.

g71p100q2oou0w0f50 block nos for profile no finish cuts

n100g0x29

n200g1z-28f50

g0x50z5

m5

m30

where am I going wrong

thanks Geoff

How are you going to get a 28" bar into a lathe with 14" between ctrs?

Jason its mm sorry if that wasn't clear its the principle 0f g71 I need to understand

Geoff have a look on practicalmachinist.com/needG71info. Seems there are two sorts, one line and two line, from what I remember you start at first cut diameter in X with clearance in Z

Hi if your stock size is 45 mm i would rapid move to G00 X 46. M08;coolant on, then rapid move to G00 Z1.; Then G71P101Q102U.2W.1D.5F.2: this will leave .2 on the diameter and .1 on the face for a finishing cut, it will take a .5 depth of cut at a .2 feed rate, then the following.. N101Z1.G00X28.5; (diameter required) G01G42Z0.F.1; (turns tool nose compensation on and feeds to Z0.also finishing cut feed rate.1) G01Z-28; (feeds to Z-28) G01X45.5; (feeds up the rear face) G40; (tool compensation off) N102; G70P101Q102; (finish cut amount left on in G71) M09; (coolant off). G00X200.Z300.; M30; may make a bit of sense.