Fastest cheapest way to make quantities of PCBs?

[3v0]

ghostman take a look at the . I use it for drilling. Thinking about it maybe the newer versions of eagle may have similar.

It is not all that hard to setup. The defaults may even work.

 

[ghostman11]

thanks for that 3v0. i will also have to look into altium and see what kind of code that generates as i dont use eagle. i have mach3 wich came with the machine. i will take some pics on my first PCB attempt , its a A3 size i got it from theese people https://www.worldofcnc.com/cnc-rout...crew-assembled-cnc-router-package-p-1327.html infact they are literaly 15 mins down the road from me . i looked at getting a vacume bed at the time but the cost put me off.
my PCB stock comes from the states and is very thin and comes bent and all kinds of shapes lol i run it through the laminator and it gets its pretty straight, ive been looking on the CNC forum for ideas on how to fix it to the bed. ive ordered some 60 degree bits to have a go at milling some fine traces and some small mills for drilling so in a couple of weeks i should be ready to have a go. i will take plenty pics and post (should at least be worth a laugh lol)

 

[3v0]

Given that you do not have dead flat PCB stock I suggest you stick with just drilling with the mill. I drill first then etch. Both ways work.

 

[ghostman11]

i only intend doing boards with the smallest traces on the mill so for theese i will get better stock, but i hope to drill all boards on the mill and of course shape them if they need it to fit a particular housing

 

[3v0]

My fear, and it may be unfounded, is that small traces will lift when milling. Let me know how it goes.

 

[ghostman11]

My fear, and it may be unfounded, is that small traces will lift when milling. Let me know how it goes.

your fears are well founded however on that web site i was linked too is a guy that manufactures bits and they have been working on mills for PCB's so things are way better than they were! lets calll it BETA stage

 

[panic mode]

I have not seen it being an issue so i would not worry about that.
we only use FR4 and we milled 0.005" - never had A trace lift off.
once we also did 0.003" and none of the traces came off.
normally we try not to go below 0.008" for other reasons.

 

[Mickster]

<snip>
my PCB stock comes from the states and is very thin and comes bent and all kinds of shapes lol i run it through the laminator and it gets its pretty straight, ive been looking on the CNC forum for ideas on how to fix it to the bed.
</snip>

When I had my mill up & running, I had a sacrificial surface mounted in the form of a piece of flipped kitchen worktop cut-off. It was levelled first using the mill, then the PCB's I did do (very few) were attached using B&Q's own carpet tape. They weren't fine-pitch boards, or even remotely complex boards, just mainly test pieces, but they turned out okay. Sorry, no photo's.

For the price of a roll of tape & some scrap worktop, might be worth a shot?

Regards.

 

[bryan1]

G'day Guy's,
What I had planned for doing pcb boards on my cnc mill (which still needs the Z axis) was to make some brass strips 1/4" thick and varying lengths, then tap some M4 or M6 holes in the rear of the strip and some thru holes just before the centre on the front edge. With the 20mm thick electrical board I have for a cnc table rows of M6 tapped holes would be placed in a grid and used for the strips. By milling a thin flat edge on the front underside a very efficient clamping setup can be done which will clamp all sides of the board flat to stop the board moving.

Now for a poormans vacuum which could work would be grab a compressor out of an old fridge and use that. Basically it blows and sucks and some trials have found on a flat surface when the vacuum is applied one can't lift the board off.

Regards Bryan

P.S. All this talk of pcb milling has now got me itching to design and make a new Z axis for my mill and go for a search on fleabay for a cheap ball screw for it......

 

[jbeng]

Another way you can use your cnc to make a pcb is to attach a etch-resistant pen in place of the milling head. Basically, use it as a plotter and draw the pattern on the FR4, then etch the board chemically.

I have an 80's vintage HP 7220c flatbed plotter and I've had very good results with this method. The only drawback being minimum trace width is somewhat large at about 0.015 in. (0.38mm) Of course, width of the pen tip determines the trace width, so you could probably get even thinner traces if you use the right pen.

 

[ghostman11]

Another way you can use your cnc to make a pcb is to attach a etch-resistant pen in place of the milling head. Basically, use it as a plotter and draw the pattern on the FR4, then etch the board chemically.

I have an 80's vintage HP 7220c flatbed plotter and I've had very good results with this method. The only drawback being minimum trace width is somewhat large at about 0.015 in. (0.38mm) Of course, width of the pen tip determines the trace width, so you could probably get even thinner traces if you use the right pen.

thats an interesting idea for plotters! BTW you can get artists pens that are way way thinner than that and you can get the resistant ink. i would like a flatbed plotter for all kinds of reasons but they never seem to be cheap where i live

 

[jbeng]

I bought mine off ebay a couple years ago. A coworker and I bought a pair of them for $75US plus shipping. It's built like a tank.

I've only tried a couple of different pens. But since the art supply stores in my area don't stock much of a variety, I have to order pretty much everything. The pen I use (Sharpie Industrial, extra fine point) works well for my application. I had to cut up an old plotter pen to make an adapter for the Sharpie, but that was no big deal.