Homebrew PCBs

On Fri, 02 Jul 2004 20:56:35 -0000, Phil <phil1960us@...> wrote:

> My point is that the driver has to convert it to the dot grid  -
> there are always conversions taking place.  You will almost never
> have an exact number of dots or exact dot alignment even if you start
> with the English system.  Its all arbitrary and the dot grid causes
> fractional dots to be truncate or rounded up.  You will always have
> fractional dots to deal with - metric or English.  I doubt seriously
> that there is less precision (or more loss) when starting with metric.


you need evidence? i can provide scans.
If you look through a engligh resolution grid on a metric picture you will
get unevenly spaced and unevenly wide tracks. ALWAYS.

If you look through a english grid on english picture you will get EVEN
results. maybe you will get 2 points, maybe 3, but always the same.
If you slide the grid you can change between the two (for example).


if you still don't believe it i will make 2 scans for you.
there is way more trouble with metric spacing, and you can get a higher
number of traces on a english grid.


>
> There's a lot wrong with the English system but this isn't one of
> them.
>

The wrong thing is that the printers use dpi and not metric resolution.

> I'll stick to my 567 DPCM printer (er, 1440 DPI) with its tiny
> fractional dot inaccuracies.  I much prefer my 10 mil traces being 14
> dots wide with a max of 0.07% error - probably better than the
> accuracy of TT.
>


the tt is fine, and i have nice 6,66 mil or 10mil traces, but metric 
flatpacks are a pain.

ST