Hey guys:
I have an early 80s 6TA on an Okuma lathe. I have some 1.5" dia. brass, by 1.035 long. Hanging on to .25" in the chuck. Attempting (futilely) to turn a .75" full radius on the end. Trying to use G71 to rough, which works, but then the finish pass gets wacky. I tried using both the G70 and long hand code, but I get the same (bad) results.
Example code:
N10 G00 X1.6 Z.1 T0404 (rapid close to part and call tool offset)
N20 G01 G42 X1.503 Z0 (moving to start position, .003 larger than actual stock to allow radius to sweep off cleanly, calling radius comp)
N30 G71 P30 Q40 U.04 W.02 D200 F.005 (roughing seems to work ok)
N40 G01 X.003 F.003 (move to start of radius)
N50 G03 X1.503 Z-.75 K-.75 F.001 (cut radius)
N60 G00 X1.6 (cancel G71 and clear out of cut)
N70 G00 Z0 (move back to beginning of cut)
N80 G01 X.003 F.003 (move to start of radius for finish pass- this is where trouble occurs)
N90 G03 X1.503 Z-.75 K-.75 F.001 (cut radius)
N100 G00 X1.6 (clear out)
N110 G28 U0 W0 (send turret home)
The problem is this- at N80, as X starts heading towards the center of the part, Z starts moving negative as well. Even though there's no Z movement called for. Also, X stops at .333, and then continues with N90 from there. What the hell? This happens with the long hand finishing cycle as above, as well as if I use a G70 after N50.
Any ideas as to what is going wrong here? I've looked extensively through the manual, but as many of you know, the old Fanuc manuals leave a lot to be desired.
Thanks!
Kevin
I have an early 80s 6TA on an Okuma lathe. I have some 1.5" dia. brass, by 1.035 long. Hanging on to .25" in the chuck. Attempting (futilely) to turn a .75" full radius on the end. Trying to use G71 to rough, which works, but then the finish pass gets wacky. I tried using both the G70 and long hand code, but I get the same (bad) results.
Example code:
N10 G00 X1.6 Z.1 T0404 (rapid close to part and call tool offset)
N20 G01 G42 X1.503 Z0 (moving to start position, .003 larger than actual stock to allow radius to sweep off cleanly, calling radius comp)
N30 G71 P30 Q40 U.04 W.02 D200 F.005 (roughing seems to work ok)
N40 G01 X.003 F.003 (move to start of radius)
N50 G03 X1.503 Z-.75 K-.75 F.001 (cut radius)
N60 G00 X1.6 (cancel G71 and clear out of cut)
N70 G00 Z0 (move back to beginning of cut)
N80 G01 X.003 F.003 (move to start of radius for finish pass- this is where trouble occurs)
N90 G03 X1.503 Z-.75 K-.75 F.001 (cut radius)
N100 G00 X1.6 (clear out)
N110 G28 U0 W0 (send turret home)
The problem is this- at N80, as X starts heading towards the center of the part, Z starts moving negative as well. Even though there's no Z movement called for. Also, X stops at .333, and then continues with N90 from there. What the hell? This happens with the long hand finishing cycle as above, as well as if I use a G70 after N50.
Any ideas as to what is going wrong here? I've looked extensively through the manual, but as many of you know, the old Fanuc manuals leave a lot to be desired.
Thanks!
Kevin