CNC Engraver for making pcb's

[dr pepper]

OK so I've made pcb's before, I've also worked with G code cnc machines.
But never on an engraver.
What sort of setup would I need?, I see engraved pcb's just take out a minimal amount of copper instead of etching a load away.
Would I need special design software, or some sort of post processor to make engraver compatible files.

 

[ClydeCrashKop]

There is info about my machine & software I used here.

https://www.electro-tech-online.com/threads/small-cnc-machines-for-making-pc-boards.144544/

I am about to make my 4th board now.

 

[MaxHeadRoom78]

If you look at the Gerber file, is has X,Y coordinates similar to a G code, you would need to obtain a Gerber interpreter to use these on a engraver.
Max.

 

[large_ghostman]

can you link to the engraver? is it the small cnc type? I use mach 3 and cad cam software on a cnc, I cant do pcb's on mine mainly because I buy cheap thin pcb boards of non uniform thickness (I am a skin flint)

 

[gophert]

OK so I've made pcb's before, I've also worked with G code cnc machines.
But never on an engraver.
What sort of setup would I need?, I see engraved pcb's just take out a minimal amount of copper instead of etching a load away.
Would I need special design software, or some sort of post processor to make engraver compatible files.

I think you can use DesignSpark pcb software. There are a bunch of supported outputs including pen plotter - I would imagine that is similar to what you will need - I think the HPGL code is fairly close to G-code as well. If not, look deeper, I know someone used DesignSpark and one of the output types recently.

Also, the flood fill lets you fill all of the un-cut areas and just leave engraver traces and islands.

 

[ClydeCrashKop]

This is the one I did today. It turned out perfect.
About 200 holes & didn't break a drill.
40 minutes to cut the traces & 25 minutes to drill the holes.

 

[dr pepper]

Thats pretty good.
On a sensitive circuit you could put some links in to ground all mass sections.
I'm creating a list of possible software and will look into each one.
Having all the holes drilled for you is a bonus.
Just out of interest what did you use for a cutter, how much are they and how long do they last.

 

[ClydeCrashKop]

These are the engraving bits that I use.
**broken link removed**
Cutting 0.010" deep at up to 15 inches per minute. As you can see from that board, they leave nice clean edges. I didn't clean it up at all.

I use drill bits like these.
**broken link removed**
PCB G code, https://pcbgcode.com/ gives you an option to center mark each hole with the engraving tool. I use that so those tiny drill bits don't wander & break.

I haven't worn any of them out but I have only made 4 boards.

 

[dr pepper]

OK, so not that expensive.
I wonder if the carbide is 1st or 2nd, still they arent expensive.
I have worn out a few 0.8 bits drilling boards by hand, I used to be able to sharpen then when I was still able to see well enough.

 

[ronsimpson]

This is the one I did today.

I made a board like that once. (no solder mask) I had a real problem with solder bridges. For some reason the solder wants to jump the gap.

 

[Nigel Goodwin]

I made a board like that once. (no solder mask) I had a real problem with solder bridges. For some reason the solder wants to jump the gap.

Solder does - due to surface tension - hence the use of solder mask to reduce it.

You just have to be more careful on a plain board.

 

[dr pepper]

Having etched my own and having had them made with a solder mask and overlay I can say all the troubles have been with the ones I've etched myself, I had a batch of photo board that sort of turned into chequers part way through etching, and left some tiny lines of copper shorting ic pads.