Engraving a PCB

[ward]

This might be a stupid question, I'm a complete newbie to CNC engraving.

In PCB design, you draw what should be left as coppertraces.

I have acces to a CNC engraver,
but normal operation on this machine is that you draw what should be engraved away,
save it as a dxf, the machine software converts to milling paths.

How can I,
draw what should be left,
and engrave the rest away.

And a second question,
on a dual layer pcb,
is it possible to 'diy' trough plated holes ?

 

[livingnote]

Don't know about pcb engraving but sure you can DIY through-plated holes. Riveting or soldering wire, both works.

 

[gyraf]

Yes, you can engrave or route the pcb in stead of etching - it just requires a pcb drawing program that will output gerber- or plotterfiles that are outlines of the traces.

Luny-Tune just made a LA4 pcb that way - http://www.groupdiy.com/index.php?topic=30780.0

Jakob E.

 

[sahib]

The key is the toolpathing.

Think of it as a negative.

Draw your artwork as normal.

Colour the the gaps between the tracks.

Give it to the guy who is going route it and ask him that the coloured bits are going to be routed out.

He will toolpath it accordingly and produce the NC file for routing.

 

[toffifee]

I use SPRINT Layout 5.0 from ABACOM (it´s only 40,- Euros). It has an export function especially for PCB milling, so you can design your PCBs without thinking about the toolpath, and later the software does all the rest for you. Works like a charm and is very easy to operate.

 

[sahib]

I have just checked it. It is a pretty good PCB design software. However, unless that software has the particular CNC being used in its library it won't communicate with the machine. Therefore, you will end up importing it to the software the machine uses and toolpath it there. I think what the question was anyhow.

What machine do you use?

 

[toffifee]

I have just checked it. It is a pretty good PCB design software. However, unless that software has the particular CNC being used in its library it won't communicate with the machine.

Yes, the PCB software does not communicate with the mill - and that is not necessary. It outputs a HPGL file, which can be imported by the software your mill works with (hopefully). Original poster Ward wrote that his mill can read dxf files; you can convert HPGL files to dxf files (for example with TurboCAD).

Therefore, you will end up importing it to the software the machine uses and toolpath it there. I think what the question was anyhow.

I think the original question was not how you create the final toolpath with all the information your mill needs, but how you basically transfer your PCB traces to outlines from PCB traces. This is done by SPRINT. After that you import this file to your milling software (as you pointed out).
And there is another advantage using SPRINT: since I use engraving bits for PCB milling, I don´t have to care for correcting the diameter of the milling tool in my milling software! So I can directly mill the files created with SPRINT, without doing any corrections in my milling software (of course you have to do basic things like setting the speed of the milling process or adjusting z=0 and so on...).

What machine do you use?

I use a "hobby" 3-axis cnc router made of aluminium, built by a german company (don´t want to do advertising here); I run it with the "CNC-Graf" software, which uses a special hardware controller to generate the signals for the driver electronics of the stepper motors.

Cheers, Christoph aka Toff

 

[Ptownkid]

there's a couple gcode ulp's available from cadsofts webpage to output gcode from eagle.