Pcb notes.

Mostly Printed CNC - MPCNC Troubleshooting
1

I got a working pcb built. And learned a crazy a,out getting it going.

  1. Make sure the area is flat… Extremely flat.
  2. Is your pcb flat?
  3. It your are building close to the edge of your board make sure it’s exactly square.
  4. You probably want to print the mirrored bottom image it you want to mount your parts on the other side. Check this before you print.
  5. There are tons of header pins in fritzing. Check that the pin distance matches what you used.
  6. In fritzing set the auto router to use extra large traces.
  7. Use Inkscape to turn lines to paths, don’t forget to union the,.
  8. If you are using an engraving bit, don’t move it when it’s really close to the board, you may break a tip.
  9. Slow movement gives higher quality pcb. I used x and y of 2mm/s and z of 1mm/s.
  10. Engraving depth of .03mm is just about right. .1mm is too much and .02mm is not enough on my board.
  11. Make your pads as big as you can.
  12. Use jumper wires to fix your board errors.

Things to still figure out: engrave the outside of the line. How do you do that? Tried the obvious option in estlcam but it looked the same.

And here’s the finished product.

image-6.jpeg
image-6.jpeg2048×1536 516 KB

2

Is that copper? and you cut around the traces to isolate it? Looks cool man

3

Yes, it’s called FR4 (it’s essentially copper foil on top of fiberglass.) that’s where tiny fractions of a mm in leg height would cause issues. My cut depth was only .03mm.

4

Have you ever tried eagle camsoftware with flatcam?
The workflow is:
Eagle->gerber(and excellon)files->flatcam->gcode.

It seems to be a little complicated but is not. You just need to invest 2days for learning and you are good to go.

And after all you end up with the knowledge that lets you make make proffesional pcb’s,prepare gerber files in case you want send your board to any pcb factory.

Perhaps I’ll show some pcb jobs from my machine, when I get to my workshop.

Regards.

5

John,
maybe you can share the spindle speed vs feed-rate you are using. And maybe bit types for milling the board cutout and etching layers?
regards
Dev

6

spindle speed is “whatever the router provides when it’s turned on”. I haven’t built any control for that yet. speed is fairly slow, but I don’t remember specifically what I set it to.

I’ve recently retired fritzing for sprint layout and the world is a much better place.

the workflow (most recently) is: Sprint Layout -> EStlcam (mill outside the line) -> gcode.
I posted the next board I created using this method and it’s significantly better than the first.

I’ve built a couple circuits in Eagle and just haven’t spent enough time to really get to know it. Sprint layout on the other hand, took me about 30 minutes to get pretty good at. plus, I have the addition of someone nearby that is also very good at sprint layout.

i’ll try to look up the federate when I get home…