I hope this image has made it onto the thread. If not here is a link to it.

http://clachanwood.wordpress.com/?attachment_id=818It is quite hard to see the problem on it's own so I have fitted the dodgy circle into a circular rebate I did using a post processor without arcs.

The code I used is as follows, for the defective circle.

G17

G0Z12.400

G0X0.000Y0.000S18000M3G04P15

G0X-78.000Y-0.000Z12.400

G1Z-4.650F5100.0

G3X0.000Y-78.000I78.000J-0.000F9900.0

G3X78.000Y0.000I0.000J78.000

G3X0.000Y78.000I-78.000J0.000

G3X-78.000Y-0.000I0.000J-78.000

G1Z-9.300F5100.0

G3X0.000Y-78.000I78.000J-0.000F9900.0

G3X78.000Y0.000I0.000J78.000

G3X0.000Y78.000I-78.000J0.000

G3X-78.000Y-0.000I0.000J-78.000

G1Z-13.950F5100.0

G3X0.000Y-78.000I78.000J-0.000F9900.0

G3X78.000Y0.000I0.000J78.000

G3X0.000Y78.000I-78.000J0.000

G3X-78.000Y-0.000I0.000J-78.000

G1Z-18.600F5100.0

G3X0.000Y-78.000I78.000J-0.000F9900.0

G3X78.000Y0.000I0.000J78.000

G3X0.000Y78.000I-78.000J0.000

G3X-78.000Y-0.000I0.000J-78.000

G0Z12.400

G0X0.000Y0.000

G0Z12.400

M05

G0X0.000Y0.000

M30