Re: milling pc boards (was: hobbyists strike again)

At 04:03 PM 10/30/1999 , you wrote:

>From: Andrew Werby <drewid@...>
>[How did you like the Danplot/Dancad combo? What would you use if you
>wanted to do this now? What about the DeskNC stuff?]

Danplot/Dancam was okay at the time, because it was the only freeware
available at the time for step and direction CNC control, but now there is
so much out there that is more powerful. Right now, I use Vector 7,
Autocad 2000, and EMC for my setup. That takes care of most anything that
I need to do (except for the fact that 2 out of the 3 run in Windows).
Dancam/Danplot doesn't accept G-code input, so if you need to mill a
complex contour, you couldn't use your favorite CAM program to generate the
code. I got fairly good at Dancad, but it was very limited. For the life
of me, I couldn't figure out how to do offsets for the cutter- so it ended
up being useless right there. After I got tired of it, I bought Maxnc
Deluxe, which accepted G-codes and did automatic cutter offseting
(G41,G42). It works pretty well. I am using EMC now, because it is even
more powerful than Maxnc.

>[How did that work? Were you just removing copper, or was there some
>fiberglass being removed as well?]

Unfortunately, I was cutting into the fiberglass too. This was a function
of my experience at the time. This is not good for the ways on the
machine! If I had to do just a few pc boards, I would probably mill them
again, but If it was a production run- I would have a board house do it.

>
> My
>cutters were carbide v bits that I ground by hand.
>
>[You actually fabricated these cutters from scratch, or do you mean that
>you kept grinding them down as they wore out, sort of like sharpening a
>pencil?]

I took 1/8" carbide router bits that were wore out (surplus from work) and
ground a V on the end -freehand. Then ground away half the diameter. This
is not very exact, but it worked and it works for engraving too. I was
surprised at how well it worked.

> It takes time to outline the traces in
>Autocad, but I'm sure that one could use Protel Easy Trax or something
>similar to do it faster.
>
>[I'm not familiar with this one- could you tell us about it?]
>

In the past, I have tried the Dos version of Protel Easy Trax and it was
fairly functional. It is a PCB drawing program that can do a lot for a
hobbiest. I wouldn't even know where to get it now, it's been a couple of
years. The thing that I didn't like about it- for my application- was
that it drew the traces with lines terminating the ends- so that each and
every trace appearred as an island. So the cutter would have seperated all
the traces from the pads making the whole thing useless. Sorry that I
don't have a better description. I'm sure there are better solutions.

Dan Falck