Need Help!- Fanuc 15TF Cylindrical Interpolation

[Valve]

Hi there fellow enthusiasts, I have a problem with programming a circular tool path on the outside of a bar in the c-axis using cylindrical interpolation. I have a Fanuc 15 TF but my manual is Fanuc 15 B (it doesn't cover A types).
The G code for cylindrical interpolation is G07.1
When I program the following, the Z axis movs but the C doesn't rotate.
The lathe hasn't ever run the cylindrical interpolation successfully to my knowledge...

O0002(CYLINDRICAL INTERPOL)
G28U0.W0.
M98P9000(C-AXIS ENGAGE)
(3MM END MILL)
T1313M3(DRIVEN TOOL 3MM MILL)
G00G40G97G98S1800
G0C0.0Z10.0
X28
M1

G07.1C14000
G18Z10.0C0.0
G18G02Z20.0C10.0R10.0F50
G18G02Z10.0C0.0R10
G01X30
G07.1 C0
G17
G30U0.W0.M05
M41
M30

If I step through, the program runs to the G07.1 C14000 (the radius of the bar) and says illegal use of G code - it doesn't like the C parameter with it's radiaus in minimum units being input. If I run the program then it doesn't crap out it just doesn't move the C axis - only the Z. If I change the code to..

G07.1 C0
or remove C altogether
then the program runs but the radius carved on the outside of the bar is a squashed semi-cirle. I think it thinks the radius of the bar is much bigger diameter and so calculated the rotation of the C axis to be a small rotation - certainly not 10mm on the circumference.

Any ideas anyone? The manual is $400 - and to spend that and find out that the code isn't in there would be a real bummer.

Many thanks,
John

[dcoupar]

Try a G01 in the first block after the G07.1... G0 isn't allowed while in G07.1 mode

[Valve]

Thanks dcoupar, I tried that but no change - it still rotates C short by a few degrees. I think it must be in the G07.1 parameters. It doesn't seem to recognise / do anything with the C parameter on the G07.1 line of code. If I insert a value then C won't rotate - if I put in zero or leave it out it rotates!

[chucker]

Just wondering I think there should be an R on the 1st line under the G07.1
I have never done this just looks like it should have an R there also you may need your feed rate moved up to the G07.1 line
G07.1C14000
G18Z10.0C0.0 (R ?)
G18G02Z20.0C10.0R10.0F50
G18G02Z10.0C0.0R10
G01X30
G07.1 C0
G17
G30U0.W0.M05

[dcoupar]

You feed to X28 prior to the M1 then in the G07.1 line, specify the cylinder radius C14000. I would try using decimal points (X28. and C14.)

[Valve]

Thanks dcoupar, sorry for the delay - I havn't checked my posts. Unlucky for me it looks as if it's more of a serious problem - I had a Fanuc engineer in and he thinks because the error message is 'Invalid use of G code' that it doesn't understand the C parameter. This is possibly because either a parameter hasn't been set or the eprom hasn't the cylindrical interpolation function installed (in the firmware). Only about £2k to get it installed - I'll have to work around as this is too much for me and I have no chance of finding what parameter needs setting to enable the cylindrical interpolation - we tried. I'm going to try Z/C circular interpolation and see if I can get it to describe a radius on the surface.

[Bill Johns]

Example;
1 inch diameter hole, and a .5 endmill.

G1X.25
G03I-.25
G1X0

that will do the hole
This is with the center of the hole being X0 Y0.

[jdeere4250]

Hi John, forgot to ask which model machine tool, Nakamura ?

[Valve]

Hi Clem,

Yes, it's a Nakamura TMC 15.
Can you send me your email address pls so I can get the parameter book (in pdf format) to you?

Thanks,John