Hi Guys

Just wondering if any one can help with this using fanuc controlls.

G3 being circular interpolation
G3 can also be used to machine a helix be adding a "P" value

But from what i understood G13 is ment to be a flat helix or spiral if you like for example you could pocket out a circle cutting in ever grater spiral untill you reached the diamiter of the circle.

but when i try to run G13 all i can get is a single cirle of a given diameter with a lead in lead out.

JUST THINKING OUT LOUD NOW

would it be possible to use something like this

G18
G3 x... y.... I..... j.... P.... F.....

If im thinking about this correctly changing G17 ( X / Y plane selection )
To G18 may make it spirl in an outward motion insted of a down motion?

hmmmm......
          Please note, although no boardcode and smiley buttons are shown, they are still useable 

The manual calls G12 and G13 "circular pocket", but that's incorrect. In Mach3 all they do is cut a circle of radius I.

G12 I2 will cut a 4" circle (actually 4" + tool D.)

Mach3 has no built in code for pocketing.

ok that makes sense because that's the result I'm getting. so is there any way to spiral cut a circular pocket starting at say xo yo with a radius of 50mm?

edit: that is simpler then programing it manually maybe a macro? i haven't had the pleasure of using mach yet my personal cnc is still be constructed but has been put on hold due to the Australian $ taking a dive. so i don't know if it will or how it will react to macro......  but even so i still work with cnc's all day and it would be handy.

There's a wizard included with mach which will create the code for it.