PCB CNC router question

[Chris Wilson]

I am toying with the idea of buying a PCB CNC router for hobby usage. How does one go from say a .pdf image of a circuit board copper to a format the machine can use? Let's say I had the pdf image attached, how would I have to bring this to a format the machine can cut from? Thanks

[LA7SJA]

Usualy CNC router only likes gerberfiles but every PCB program I ever seen, used or heard off can output gerberfiles. The program used to produce the PDF should also be able to produce gerber and drill files.
If all I can get is pdf I print it on transparant 2 times glue them togheter and place them on photoresist pcb and put them outside i the sun 3min before I take it inside and develop and etch drill and populate. Google diy pcb and or toner transfer pcb. You should have more than you could ever read or watch on youtube.

Johan-Fredrik

[Chris Wilson]

This was my fear, I do boards on photo resist at the moment, with a proper etch tank and UV box. It is messy and time consuming, but a lot of projects I have done have only had the PCB design as a pdf or other  image file. I was hoping there was some clever software that could "translate" from such an image to a format a CNC machine could read. I guess I will stick to my chemicals for now, thanks for the reply

[LA7SJA]

Google "pdf to gerber file converter" I for one is not to impressed but you could download a gerber viewer and some of the pdf2gerber programs and test if a print of the gerberfrompdf files loaded in the  gerber viewer match the pdf print.

Johan-Fredrik

[andtfoot]

You could import the pdf as a picture into CAM software to then make a toolpath.
The difficult part might be keeping the scale, but as long as there is a reference point somewhere on the layout to base from it should be alright.

I use Vectric software myself for other things, and it would be able to cut based on 2D images.
http://www.vectric.com/products/cut2d.html

[Fred27]

I started with a CNC partly because I was interested in PCB isolation routing. I've actually switched to UV exposure - partly because I wanted to try it and partly because routed PCBs have far more "contour" compared to etched ones and it makes solder mask application harder.

Answering your original question, I don't think PDF to g-code will work particularly well. If you really needed to then something like inkscape might be able to trace the outline into a vector format. I can't imagine the results would be great but you could at least give that a try. Once you have a reasonable vector it would be possible but you'd be in rather unique territory.

Having said all that, I would thoroughly recommend CNC stuff as yet another expensive time consuming hobby!

[Chris Wilson]

Thanks for the very helpful and frank replies. My fears are confirmed, I think sticking with photo etching is best for me at the moment, I can do without a separate, expensive diversion with its own idiosyncrasies The conversion stuff sounds like a nightmare to someone as mathematically challenged as myself

[ajb]

If the PDF holds the PCB artwork as vector data, then any self-respecting CAD/CAM software should be able to import the vectors to use as toolpaths.  If the artwork is held as bitmap data, then you should be able to use a graphics program (or perhaps a CAD/CAM suite) to automatically trace it into a vector format.  The success of that method will depend on the quality of the source image and the results may vary with different programs. 

[wxm145]

we think you need offer a gerber file

[captainscarlet]

I find it hard to believe that your PCB software has no gerber output.

I do my CNCed PCBs with kicad.

I output the copper layers, drill layer and margin layer and import them into FlatCAM. 

FlatCAM let's me specify the particular tool paths and outputs a g code text file for my cnc.

[hendorog]

If you can create a height map (lithophane) from the image, then the perimeter of that should be the isolation routing.

I believe Cura (3d printer software) can take an image file and produce a height map STL.

That should work for isolation routing if you tell it to only generate the perimeter of the STL when you generate the gcode.