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Subject: RE: [Homebrew_PCBs] Re: laser ablation of paint on copper clad

From: "Tony Smith" <ajsmith1968@...>
Date: 2014-12-13

At 1,000 DPI, the laser isn't going to be anywhere near it's supposed to be
anyway. Close enough thought.

The beam of the laser will be probably bigger than a dot a 1,000 DPI (which
is good as the overlap fills in the gaps) depending on a bunch of things.

Dunno how LinuxCNC does rastering, but often the laser is left on between
dots so that evens things out. Sometimes you want dot - dot - dot lasering,
but not in this case.

Tony


> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com
> [mailto:Homebrew_PCBs@yahoogroups.com]
> Sent: Saturday, 13 December 2014 4:27 PM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: RE: [Homebrew_PCBs] Re: laser ablation of paint on copper clad
>
> At certain locations in the rotation angle, the laser does not fall
directly in the
> center of the pixels. How are the pixels in the bitmap mapped to their
position
> in the arc? Is the Bresenham algorithm or a similar
> algorithm used?
>
> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com
> [mailto:Homebrew_PCBs@yahoogroups.com]
> Sent: Thursday, December 11, 2014 2:30 AM
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] Re: laser ablation of paint on copper clad
>
> Hello..
> It's written in video description. The data is provided by python script.
> Well the workflow is like that:
>
> -Draw board.
> -export board to 800 or 1000DPI BW image -pass that image to python script
to
> get bitfile -load bitfile into LinuxCNC -Push start
>
> Slavko.
>
> p.s.
> It's possible to pass just BW image to Linuxcnc but the power of my
computer is
> just little to low to provide data in realtime. So I do preproces data.
> Maybe just better algorithm can solve that...
>
>
> On 11. 12. 2014 00:43, 'Boman33' boman33@... [Homebrew_PCBs]
> wrote:
> > Very nicely done!!
> >
> > What software are you using to do the bitmap or vector to rotary
> > control/firing?
> > Bertho
> >
> > -----Original Message-----
> > From: Homebrew_PCBs@yahoogroups.com
> > [mailto:Homebrew_PCBs@yahoogroups.com]
> > Sent: Wednesday, December 10, 2014 09:06
> > To: Homebrew_PCBs@yahoogroups.com
> > Subject: Re: [Homebrew_PCBs] Re: laser ablation of paint on copper
> > clad
> >
> > Just make a crapy video to show how I do that.
> > Instead to use CNC XY table and get 1200mm/min I add A rotational axis
> > and got 30159mm/min scan rate and use only Y axis to advance board
> > every revolution of arm by 0.01mm.
> >
> > The laser is mounted in aluminum arm to the stepper motor. Powering
> > stepper motor with 16 or 32x microstep was total disaster. Now I drive
> > motor in full step but picked speed where inertia of arm just coencide
> > with resonance so motion is wery smoth.
> >
> >
> > http://youtu.be/8ekioGZOkb4
> >
> >
> >
> >
> >
> > ------------------------------------
> > Posted by: "Boman33" <Boman33@...>
> > ------------------------------------
> >
> > Be sure to visit the group home and check for new Links, Files, and
> Photos:
> > http://groups.yahoo.com/group/Homebrew_PCBs
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> >
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>
>
> ------------------------------------
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> ------------------------------------
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> Be sure to visit the group home and check for new Links, Files, and
Photos:
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> ------------------------------------
> Posted by: "Jeff Heiss" <jeff.heiss@...>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and
Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
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