On Wednesday 03 August 2005 06:29 am, Olin Lathrop scribbled:
> Probably.  What width parameter did you use for it?  Small width values can
> make photoplotting (and generation of photoplotter files) take a long time.

Default of 0.016".

Just read a bit on polygons in the manual.  Found out that spacing is only 
applicable to hatch patterns.


> > Currently (over 2 hrs into the processing),
>
> Wow, that really is "long".  Usually the whole process takes a few seconds.
> The longest it ever took for me was on the QuickProto-01 board because it
> had a sea of holes with a ground polygon around them.  But that only took
> maybe a minute or two on several of the arpetures, maybe 5-10 minutes
> total.

This board is a *bit* bigger at 162 sq in.  But yes, I agree it is excessively 
long.


> > ...  I understand that an "aperture" is an individial
> > element on the board.
>
> No.  It is one of the various shapes use to draw with.  Gerber plotting is
> really a line drawing process with various shape and size "pens".  Large
> areas are drawn by going over them in a raster pattern, just like you would
> if you were trying to fill in an area with a real pen.  Of course the finer
> the pen tip, the longer this takes.
>
> Photoplotters draw with light onto film, hence the "pens" are apertures
> that result in a beam of specific size and shape.  In the old days, there
> were a few standard apertures on an aperture wheel that had fixed holes
> pre-punched into it.  Now the equipment can do variable aperture on the
> fly.

Interesting.  Never knew this.

I just got a chance to experiment with this a bit... no groundplane took about 
~2 minutes.  Groundplane with 0.016" width took ~6-7 hours.  Groundplane with 
0.05" width took ~4 minutes.  Not a lot of datapoints, but enough to prove 
that was indeed the problem.  I'll have to experiment with various settings 
next time.

Thanks,
-Neil.



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