PCB CNC: Unterschied zwischen den Versionen

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First of all you will create a PCB in a program called pcb. Then you will export gerber files from the pcb and generate ngc files with pcb2gcode. These ngc files can be read by linuxcnc.

For a Single Layer PCB you will run Steps 1,2,3,4 and 6 for a dual Layer you will run 1 to 6.

For a Single Layer PCB you will run Steps 1,2,3,4 and 7 for a dual Layer you will run 1 to 7.

=== Create the PCB ===

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[[Datei:G10command.jpg|thumb|400px|The math behind the G10 L2 command]]

This step is now crucial for the quality of the dual layer PCB.

linuxcnc gives us a command called G10 L2. This command sets the coordinate system given by offsets of machine home point. If you know now two points in the original coordinate system (= the PCB coordinate system) and write down the coordinates that have these points in machine coordinates, you can effectively calculate the G10 L2 command.

First of all you select two points in gEDA pcb. You probably want to choose two drill holes. Now you need to look up the workspace height (in the picture called <math>A_y</math>). Subtract the y coordinate from the workpiece height, these coordinates will be the original coordinates. You need to do this extra step because a) pcb uses a left-hand coordinate system and b) pcb2gcode calculates the y coordinates based on the workspace bottom line.

Now you enter G10 L2 P1 X0 Y0 R0 into the MDI field in linuxcnc. This will effectivly set the G54 coordinate system to the G53 (machine coordinates). but not the z offset (which is good because then you do not redo this).

Use a tool of your choice to calculate the G10 command and enter it.

=== Mill the Top Side ===

The top side can be milled like the bottom side, but because of the active G10 you do not need to touch of anything!

=== Mill the Outline ===

The outline is also milled like the bottom or top side. No extra step is needed!

== Usage ==