Re: convert drawing to cad file

Don't usually stick my oar in here but have done a LOT of drawing-to-CAD
conversion work for waterjet, laser cutting, CNC milling and also
architectural stuff for local engineering firms and a couple of major
hospitals on a contract basis -

While I agree that 5 to 10 years ago the software was pretty bad, it gets
better every year - I think that the main problem at this time is the usual
one associated with hobbyists and that particularly applies to
Raster-to-Vector conversion which is -- "Cheap software isn't Good - Good
software isn't Cheap" - This may change, hopefully, but that is the current
situation -

I use GTX RasterCAD and have also used CadOverlay on a trial basis - Both
can convert into arcs rather than lots of short line segments - However you
are talking about relatively high prices - (Several thousands of $ for the
high end stuff) - Hardly reasonable for a strictly hobby use -

Good semi-automatic conversion is possible at this time, but there is still
quite a bit of clean-up work to be done, particularly at multiple
intersections of lines and arcs - Also if you intend to do mathematically
accurate conversions for machining (within a few thousandths) you might as
well forget it - Paper stretch, scanner errors and original drawing errors
all contribute to the problem - And if you are working from an Ozalid-type
copy (blueline copy) there is a consistent growth in the dimensions in the
direction that the paper was fed through the duplicating machine that is
inherent in the process -

Roland Friestad, P.E., Contributing Editor
HOME SHOP MACHINIST
c/o Cardinal Engineering, Inc.
2211 155th Street
Cameron, IL 61423
Phone - 309-342-7474
E-Mail - cardinal.eng@...
Web Page - www.cardinaleng.com

> Message: 12
> Date: Sat, 21 Jun 2003 09:16:31 -0000
> From: "stevenson_engineers" <john@...>
> Subject: Re: convert drawing to cad file
>
> >--- In CAD_CAM_EDM_DRO@yahoogroups.com, "ds@d..." <ds@d...> wrote:
> >
> > Hi,does anyone know he best way to convert a drawing by hand to a
> >cad file
> > whats the best software to use for it,any tips.thanks a lot for any
> >help
> >
> >
>
> The best method by far is to use ANY cad system and forget the
> conversion. None of the conversion programs are worth a rats arse.
> They convert arcs to many small lines, even straight lines are
> chopped up.
> You spend more time trying to clean the drawing up than redoing it.
> If you need the drawing for a CNC machine you can get horrible
> results with all the small gaps.
> About the only place they work is converting artwork where you can
> put up with inaccurate drawings to get a shape, logo's are an example.
>
> If you find a CAD program that suits you then instead of spending the
> time messing with raster to vector programs use the time to get up to
> speed with it.
> An hour spend setting up hot keys will pay off in spades.
>
> Some years ago when I got out of hospital and couldn't work I took
> some conversion work in for a local company. They were converting
> from paper to disk. Two guys were at base using Autocad, one
> redrawing and one cleaning up scanned images. I was at home redrawing
> with a simple $500 program, my daily output was always better than
> both of theirs put together.
>
> John S.