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Eagle and Laser cutter

e14 Contributor

Has anyone here used a laser cutter in conjunction with eagle to make pcbs?

 

im using pcb-gcode to create the code to use with a milling machine (modding it to turn the laser on and off once it generates the code), then running it through EMC2 that controls our 40w cutter. I spray paint the side of the copper board I intend to use and vaporize the traces with the laser...

 

im just curious if anyone else has a similar workflow, the only real problem I'm having is spotting/marking the holes so enough copper gets etched away so my hand drilling is a bit more accurate (yes I could completely use a drill press but I don't have one image )

 

MAybe a modified method that results in bigger holes being marked?

 

 

 

thanks for reading!

  • 0 in reply to Problemchild

    How did you give yourself a "helpful answer" on your reply .... you could make a ton of points by answering your own question ....BUG TIMe ..LOL image

  • 0 in reply to e14 Contributor

    That's a good result then. I'm sure you can remove the resist at least as accurately as any hope process can remove the underlying copper so you are good there. The laser hole thing may well be a pain as you will need some lugs or some such on the bed to align the board again to get the correct registration. Another issue I find is that the FR4 has a tendency to char, maybe that wont be such an issue for just the holes and after all you will be soldering over them any way image

     

    Thanks for the links BTW!

  • 0 in reply to Problemchild

    Previously I was using toner transfers to do PCBs. The images posted here are from my first attempt at lasered PCB's (which still need to be etched afterwards anyway image )

     

    The original place for the pcb-gcode plugin is pcbgcode.org, which is meant for milling the board using a mechanical cutter.

     

     

    My modified version can be found https://www.dropbox.com/s/jsx7z02rd623boq/pcb-gcode3.6.2.4-laser.zip  and should have a bunch of warnings attached to it but doesn't image

    (My cutter is setup to where that spindle on/off turns the laser on/off; the modified code turns the laser on when the Z is negative and off when the Z is positive)

    I would dry run any output from this first...

     

    Here's a board from the newer code, its not perfect but my hand drilled holes are a little better since I had better markers...

    image

     

     

    Perhaps later I can try putting the board back after etching and have the laser cut the holes since theres no copper protecting them now image

  • 0

    You said here you are using the Toner transfer method I assume you haven't tried the laser yet then . If that is the Laser then I'm pretty impressed. I would also say stay with vector formats and avoid raster like the plague as although you have enough accuracy you do cannot switch off the beam fast enough for a clean edge as it takes several ms to stop lasing and just messes up the etch resist.

     

    Most of the laser software don't take GCode at least the Chinese variety if you can create a DXF then you can import that into almost all the Software. BTW eagle provided a load of tools to do this but I've not tried as it was windows only..

     

    Good luck ....Do you have a link to the pcb-gcode thing BTW?????

  • 0 in reply to dougw

    40W just doesn't seem like it will... Now I am scared to put it at full power though

     

    after a night of poorly reading their code and the better part of this morning hacking together some code, I have managed to modify pcb-gcode to do what i want... It's currently being tested but at least I can go from Eagle to my laser cutter without manually editing the output now image

     

    Ill post results a bit later

  • 0 in reply to e14 Contributor

    Looks good.

    It also looks like you have enough laser accuracy to make the pads a bit bigger and easier to drill. A smaller drill bit might help as well.

    I would try to go through the copper with a center punch to provide a drill guide, but might also try a secondary punch to break the copper circles so the drill doesn't tear up the copper.

    You could make the second punch with a broken drill bit shaft (with the correct hole diameter) - grind it flat or concave if you can and use it as a punch just to break through the copper layer, or at least define where the copper will get cut.

    Another trick is to stick a piece of clear tape on the copper side (or both sides) before drilling - this reinforces the copper you don't want removed and minimizes burrs.

    I guess it is too much to ask the laser to burn all the way through the copper so you could skip the etching step?

  • 0 in reply to dougw

    Well I haven't really messed with trace thickness since throughout my PCB making I've purposely made the traces as long as I could because I was using the toner transfer method...

     

    But here's some pictures of the first board I have done and messed up image

     

    image

     

    image

     

    image

  • 0

    Very interesting approach.

    I would like to see an example picture of a finished pcb to see how it compares to mechanical machining/engraving methods.

    What kind of trace width and spacing can you achieve?

    How fast does it vaporize (mm / minute)?

    Maybe a needle-point center-punch would improve drilling accuracy....