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I have a simple question, I'm saving a DXF file as R12, but I can't find the group codes 210 220 and 230 for arcs. This is a piece of the DXF file:

  0
ARC
  5
44
  8
0
  6
CONTINUOUS
 62
     7
 10
0.0
 20
0.0
 30
0.0
 40
180.0
 50
0.0
 51
180.0
  0
ARC
  5

Do I need to save this dxf file as an other version? I need this information for specifying the rotation of the arc... (CW or CCW). Thanks for the help!

Henry
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1 Answers1

2

The help documentation provided by AutoDesk indicate that the 210 / 220 / 230 values are for the extrusion and are optional.

DXF Arc values

The help documentation also states:

Arcs are drawn in a counterclockwise direction by default. Hold down the Ctrl key as you drag to draw in a clockwise direction.

The rotation of the arc is attributes 50 and 51 (expressed in radians). Unless, you are referring to the 3D rotation (relative to another view). In which case those attributes are required. But if you are in the World Coordinate System (WCS) when you create your arcs the extrusions are not required.

Andrew Truckle
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  • Okay. But I want to write Gcode from this dxf file, so I will need the arc rotation direction for writing Gcode. Is there a way to find this direction? E.g. saving it as an other format or something? – Henry May 03 '16 at 12:11
  • Do you have Autocad? Or Bricscad? You could create some arcs at different angles and dxf them out and examine the radian values. You will then be able to work out the rotation direction based on the two angles. – Andrew Truckle May 03 '16 at 12:17
  • I just created two arcs in Autocad in opposite directions and saved as R12 DXF. The start / end angle values were correct (actually in degrees - not radians). They both had the same values. – Andrew Truckle May 03 '16 at 12:23
  • Add it would appear that the angles are expressed in counter clockwise direction. – Andrew Truckle May 03 '16 at 12:24
  • And it does not matter if in AutoCAD the user changes the direction setting to clockwise. The DXF is the same angle values in degrees. – Andrew Truckle May 03 '16 at 12:25
  • So they are counter clockwise, from 3 o'clock. – Andrew Truckle May 03 '16 at 12:27
  • And if you are on about the extrusion direction - the details I showed you indicate the default is 0, 0, 1. – Andrew Truckle May 03 '16 at 12:29
  • If I have answered your question correctly can you please mark it? Thank you. :) – Andrew Truckle May 03 '16 at 17:15