Homebrew PCBs

> 
> And the flames..........
> 
> >
> >  #1) PIC's are not free.  the flip side of what you say is that for
> >  zero dollars, I can rip apart a printer cable, pull the ends out
to my
> >  drivers and run a machine from DOS.  free.
> 
> Are your drivers free? the printer cable had to be bought at some
> stage, PICS, and it could be done on one big one, are not that
> expensive, how much is a copy of DOS, I dont have that...

that match was to light the candle, not the blow-torch ! : )

the driver board would probably be on par with a PIC based driver. 
the MOSFETS and supporting circuity is not that much differnet than
any of the single chip solutions.

As for software, I am asuming that no matter what you use, you are
using a PC to create the Gerber files that will be used for the CNC
machine.

My point is that you can use that computer both for creating the
layout as well as running the machine.

Would you be able to put all the axes (up to 6?) in one PIC, and I
assume that the microstepping part would be a complete external
circuit ?  that, or you would need some way to set the microstepping
level.


 
> 
> >  #2) PIC's are not free. you have to have a programmer, or you have to
> >  buy one pre-programmed.  Either way, it costs money.
> 
> Thats why we have these little groups, to help each other, you know
> that printer cable of yours, you could program a PIC with that, or
> someone in the group could do it for a small fee, I would do it.


I would LOVE to have such a unit.  Especially if it were open source.

As I see it, one would have to download the cut file(s)  for making a
pcb, there is usually a drill layer with different drill bits. you
would need a display of some sort to prompt the user what size bit to
use or what cutter is needed.

You would need to be able to select which layer you wanted to run.  It
could be from the download, where you download a layer, then cut it,
or maybe download all the cut layers and then select which one you
want to cut.

I can see it is possible.  I am not sure how you would interface the
monitor/screen to show the cut path as the work progressed, but I
guess you could leave that part out to save some $$.  Maybe if there
were 2 usb ports on the controller, one could send the cut path
information back to the PC so the PC could show the cut path ?

I guess some of those details would need to be worked out.



Dave