I saw few attempts too.
Well wraping pcb to drum is near inposible.
Using simple homemade CNC with laser attached has some drawback. If it's
accurate then is probably slow. Acceleration and deceleration cause
problems with vector drawing so the best is to use raster style. When
you are in raster then you need smal dot, and even smaller stepping or
angled traces will be fuzzy.
I see the machine of one german freak that use poligon mirror to scan
one axis. Seems very nice but since there are no F Theta lenses they
have different dot size depending on position. And difference of 1mm out
of focus is unusable. So I thinkering how to scan fast and to have laser
in same distance from board and that idea arrive. It works. Now after
few hours working even little problems caused by brushes seems to
dissapears. Seems that brushes align with slip ring and now the contact
is good. If you didn't realyzed the laser got power from 4 carbon
brushes as laser rotate but driver is stationary.
Works nice for now. Just need to add index sensor to know position of
laser (as til now I align laser by eye)
Slavko.
On 11. 12. 2014 16:01, 'Boman33' boman33@... [Homebrew_PCBs] wrote:
> I saw your video previously and I understand how it works.
>
> Maybe I misunderstood your comment in your previous email:
> "> Hello.
>> It's written in video description."
> It sounds like you have a written description of video processing.
>
> By the way, another member did a similar setup but for film and he wrapped
> it around a drum like an ancient fax machine.
> There was also a member that converted an inkjet printer to a direct photo
> plotter.
>
> I really like your solution.
> Bertho
>
> -----Original Message-----
> From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
> Sent: Thursday, December 11, 2014 04:01
> To: Homebrew_PCBs@yahoogroups.com
> Subject: Re: [Homebrew_PCBs] Re: laser ablation of paint on copper clad
>
> youtube link posted below..
>
> On 11. 12. 2014 09:36, 'Boman33' boman33@... [Homebrew_PCBs] wrote:
>> Thanks Slavko for responding.
>> Do you have a link where I can see the video description you mentioned?
>> Bertho
>>
>> -----Original Message-----
>> From: Homebrew_PCBs@yahoogroups.com
>> [mailto:Homebrew_PCBs@yahoogroups.com]
>> Sent: Thursday, December 11, 2014 02:30
>> 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
>>> ------------------------------------
>>>
>>> Yahoo Groups Links
>>>
>>>
>>>
>>>
>>
>> ------------------------------------
>>
>> ------------------------------------
>>
>> Be sure to visit the group home and check for new Links, Files, and
> Photos:
>> http://groups.yahoo.com/group/Homebrew_PCBs
>> ------------------------------------
>>
>> Yahoo Groups Links
>>
>>
>>
>>
>>
>>
>>
>> ------------------------------------
>> 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
>> ------------------------------------
>>
>> Yahoo Groups Links
>>
>>
>>
>>
>
>
> ------------------------------------
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>
>
>
>
> ------------------------------------
> 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
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>