Old automatic cutting machines used a line-following circuit to copy
directly from a paper print.
They cut using acetylene or plasma torches, and were completely analog,
no processors.

Isaac



Em 23/10/2012 21:49, IVP escreveu:
>> And scanning with an X-Y plotter.... And a single pixel pickup...=20
>> 600mm /0.5mm =3D 1200 passes... at even 1 ms per pixel that's like
>> 24 minutes of scanning...
>>
>> your application must be... Interesting :-)
> Well, that's two of us who think it might be ;-)
>
> It's part of an idea suggested a while back about burning cutting
> patterns onto wood with a laser, primarily for fine bandsawing or
> scrollsawing
>
> The universal method presently is to print out the pattern and stick
> the paper to the wood with contact adhesive. Cut the wood and
> then remove the paper. It's quick, but glueing is a bit invasive and
> can cause staining, plus you've got more sanding
>
> The idea I'm trying is to scan the pattern, store the image, and then
> play it back through a burner. Either that or have two X-Y tables,
> one for reading, one for burning, just like you'd copy a CD, with
> no intermediate storage. Although it's very easy to store a file so
> not adding an SRAM would be short-sighted
>
> I've tried it non-mechanically and it's certainly very doable, if slow.
> For what I have set up here that's mostly due to the burning speed
> of the laser. I am considering a small router with a fine bit to do
> the drawing, pretty much a basic 2D CNC, but of course you'd
> have to make sure any routing is done outside the line and that
> would take s/w a little smarter than simple lines. Plus the size of the
> bit (1.8mm I think is the smallest commonest carbide) limits the
> resolution, but you'd pick the right jobs to use it on
>
> Woodworkers are a mellow laid-back bunch. Even if a scan and
> burn took an hour, that time can be spent on many other things in
> the workshop, especially once you have the first item to work on
>
> Joe

--=20
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