Hi Alan,
If you do a circle in GCode it has four lines of code. If
you use Eagle each circle becomes alot of points. The resulting
code for a large PCBoard is huge. I look to produce a fast efficent
GCode file. One of my DXF files is in the Files section. After I
convert a DXF to Gcode I go in and do some touchup. With a large file
changing all the Z-002.45 to Z-002.46 takes for ever. I use an old
version of KCam that was FREEWARE. It has problems with large files.
Simple circuit boards with only one or two IC mask the problems
that show up on large boards. Learning a few tricks now will pay off
later.
When you draw in DXF, you can have traces share a border. This
cuts cutting time and wear on the tool. My large circuit boards have
500 inches of cutting distance. The new board I just designed has 600
inches of cutting. Simple hobby circuits might have 50 inches. This
is why you will see people reporting success with different cutting
tools. For large boards you need Carbide or Diamond.
When your machine cuts a board how much extra traveling are you
getting. That's where the machine cuts here, then there, then over
there. The ACE converter takes the unwanted moves out. I don't use
ACE myself. I have found that the GCode will turn out just the way
the DXF is drawn. So I draw the DXF, then I trace it in a nice
orderly manor. I save the trace! The results is the machine cuts
moves a little and it cuts again.
As for your OT question. I was told I should have gone for a
Goverment grant.
John
--- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> Hi John,
>
> Not sure why you say it takes lots of lines of code to do round
pads!
> Although I'm working from a Gerber file (thinks pads and traces),
the
> resultant actions to draw a round pad are actually quite simple (I
don't
> generate an intermediate Gcode file... yet). There are from 1 to 4
arcs
> (for 0 to 4 traces into pad), plus a line per side of each trace,
up to
> the next pad, or a "bend" in the trace. So a simple "dog bone" of
two
> pads and a trace between would result in two arcs, and two traces!
And
> if I understand you correctly, you'd draw 7 short lines per pad,
plus
> two traces?
>
> This actually gives me an idea. If the "short lines" used to draw
the
> pads could be identified by software (a "filter" based on length?),
then
> they could be replaced by arc's. sort of like a "constant
contouring"
> algorithm. Then you'd get round pads!
>
> OR, since you're using CAD, and you always start/stop the little
line
> segments always start on 45 deg. points of a circle (I guessing
here),
> I'd suggest just specifying a arc from/to the required points at
each
> pad! That should be simple enough!
>
> Of course all this assumes you would want round pads instead of
> octagonal pads. What are your thoughts? I know you've done many
boards
> with your "system", and you have your reasons!
>
> Alan KM6VV
> P.S. Hate to mention it, and I don't know your tax setup, but
just "not
> making money" isn't enough to make you "non profit". As far as I
know
> (I'm not a tax consultant), just selling services/products makes
you a
> business (you just report little or no income from the business on
your
> schedule C). Just some thoughts, and hope this didn't offend. :>)
>
>
> crankorgan wrote:
> > <SNIP>
> > Dave is using round pads. They look nice but the cause
> > lots of lines of code. This can come back to bite you if
> > you have to rework the code. Almost one hundred lines of code for
> > each pad. I use an eight sided pad. Daves machine is very tight
> > with the use of the antibacklash nut-spindle and machined guides.
> >
> > John