DXF2GCD is a DOS-based software utility that converts graphic data contained a DXF file to ISO standard G-Code programs which can be run on engraving/milling machines with ISO compatible controllers - the output G-code program can run directly on the target machine - in case of certain special machines like Laser Engravers, etc., the necessary additional G/M codes required for machine-specific operations have to be added - this is done using any text editor.

Usage
The DXF2GCD program is invoked from the DOS prompt as follows :

DXF2GCD < input file > < output file >

 where < input file > - the .DXF file containing the graphic information
         < output file > - the .GCD file where the converted G-code program is stored.

Both the input and output file names must be specified - otherwise, the program exits with a message :

  Usage : DXF2GCD < input file > < output file >
 

Operation
The program uses a 2 pass approach - in the first pass, the program reads the input file and all entities converted to a proper data structure. In the second pass, this data structure is converted to Gcode format and stored in the output file.

The G-codes supported by this program are :

 G00   Fast movement
 G01   Linear Interpolation
 G02/03  Circular Interpolation
 G91   Incremental movement
 G86   Spindle Control ( custom made canned cycle for starting spindle )

Features

Error Checking
Error checking is provided as a safety feature. The following errors are identified :

 a. Insufficient memory.
 b. Polyline specific data encountered outside a polyline.
 c. Zero radius specified for arc or circle.

User Friendly Comments
The program moves from one entity to another in G00. In then executes each entity using G01 or G02/03 i.e. either in linear interpolation or circular interpolation. Between each entity, the program provides a comment with the entity number, so that the operator can identify the different entities.

Ordering of Entity Movements
The program does not order the entity movements - the order in which the entities are saved in the DXF file is the order in which the G-code for each entity is saved into the file.

Thus in order to plan the tool path, the operator should take care while exporting his graphics data - he should select the entities in the order in which he wants the machining to be performed.

Switching ON of the tool/spindle
While moving between entities, i.e. while it moves with G00, the program adds a M12/M13 which switches ON and OFF of the spindle respectively.

Sample output of program
% header section
N0000 G91 X0 Y0 F200.000
N0005 G65 H01 P32 Q000.200
% pen down
N0010 M12
N0015 G01 X000.000 Y-85.024
N0020 G01 X118.340 Y000.000
N0025 G01 X000.000 Y085.024
N0026 G01 X-118.340 Y000.000
% pen up
N0030 M13
% moving to next entity
N0035 G00 X-97.457 Y-78.068
% pen down
N0040 M12
N0045 G01 X059.557 Y017.005
N0050 G03 X-07.734 Y035.556 I-05.006 J017.530
N0055 G02 X-30.939 Y017.777 I-04.286 J028.352
N0060 G01 X-20.884 Y-70.338
% Pen up at end of program
N0065 M13
     N0070 M02