G02/G03: no circle/segmented circle with just one command

Hi everybody,

I fail to get G-Code that mills full/large segmented circles with just one G02/G03 command. All PPs (coming with BC) I tried so far divide (segmented) circles in two G02/G03 commands.

Note: for small segments (I do not know for the smallest angle) BC just uses one operation.

N01 G00 G17 G40 G49 G54 G80 G21 G90
N02 T6 M06
N03 G54
N04 G90 X200. Y-220. M05
N05 G43 H6 D6 Z25.
N06 Z5.
N07 Z3.
N08 G01 Z-10. F1000.
N09 G03 X-200. I-200. J0.
N10 X200. I200. J0.
N11 G00 Z5.
N12 Z25.
N13 M05
N14 G90
N15 T6 M06
N16 M30

If the circle segment is also big enough (I do not know, at which angel this occur), a split will also be done.

Why? How to fix this? Played around with 319./320./321. … without success.

Thx, Harald

Hi Harald,

BobCAD breaks arcs into smaller segments when an arc’s sweep angle is 360 degrees (or bigger for helical arcs). For an arc with a sweep angle less than 360 degrees, BobCAD should be able to output it in a single G02/G03 command line. You just need to make sure post-processor questions 221 and 223 are set to “n”.

P.S. If arcs are output with Radius instead of IJK, the post-processor question 221 should always ve set to “y”. Visit our Help System for more info.

Hello Mo,

  1. and 223. both set to “n”.
    Circle with 259° is one G2/G3 statement. 259.9° already splits into two operations (I have not tried to find out when the break occurs).

Is there a reason, why BC-CAM split below 360° and not >360°? I can only assume that a full round of 360° is not enough getting a good result and a larger circle has to be split anyway.

Bye, Harald