Homebrew_PCBs

On 12/8/2014 10:44:24 PM, 'Jeff Heiss' jeff.heiss@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:

 

I’m mentally exploring the idea of spray painting copper clad with spray paint and drawing traces in the paint with a laser.  After the laser, the board is then placed in etchant and the copper exposed by the laser is etched away.   I understand this is possible with 20W CO2 lasers by Youtube videos but has anyone explored this with a laser diode?  Is the  abundant ebay 445nm, 1W laser or the 808nm, 3W laser up for the task paint ablation?

 

Jeff

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I’m mentally exploring the idea of spray painting copper clad with spray paint and drawing traces in the paint with a laser.  After the laser, the board is then placed in etchant and the copper exposed by the laser is etched away.   I understand this is possible with 20W CO2 lasers by Youtube videos but has anyone explored this with a laser diode?  Is the  abundant ebay 445nm, 1W laser or the 808nm, 3W laser up for the task paint ablation?

Jeff

On 12/9/2014 7:25:07 AM, Howard Chester howard.chester@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:

 

Jeff posted,

>I’m mentally exploring the idea of spray painting copper clad with spray paint and drawing traces in the paint >with a laser.  After the laser, the board is then placed in etchant and the copper exposed by the laser is >etched away.   I understand this is possible with 20W CO2 lasers by Youtube videos but has anyone >explored this with a laser diode?  Is the  abundant ebay 445nm, 1W laser or the 808nm, 3W laser up for >the task paint ablation?

 

>Jeff

Hello Jeff,

Just a few words of my musings...

Why not try to replace the high power LASER with a 400nm Ultra Violet Soild State Laser Diode combined with a CD/DVD optic sled unit to expose a UV resist PCB?

A few advantages;-

1) Lower power equals safer working enviroment

2) Ease of use, the CD/DVD has a constant correcting focus control loop. This would probably allow tracks in the sub mm range(0.2mm?). As the visable red dot shining through the prism bounces back from the PCB, mixing the nearly invisible UV beam on the opposite side of the prism assembly by delivering the beam via a short lenght of cladded fiber through the unpopulated side of the prism.

3) A secondry advantage of the visible red dot is easy and accurate registration when doing double sided PCB's.

4) By tapping into the beam control(constant amplitude loop that monitors the reflected beam power to compensate for impurities on CD/DVD's  (analog available at the red laser diode Anode-Cathode as a varying Current through  the red Diode)) would allow for a "Resist thickness vs stepping motor delay"  as well as slaving the UV LASER drive current.

5) Modern Micro-stepping Motor drive IC's would maximise the resolution of the optics, unless you use the optics of the "sled" control. In which case the resolution could be in the micro/nano meter range.

6) Cost, a UV LASER Diode module costs about 45 Bucks vs BIG bucks for a large LASER, Drive Electronics and the delivery optics.

 have pondered this concept for a while now but declining health has force my early retirement and as such, my access to the nessessary engineering tools.

As stated, just my musings...

Good-luck with you project, chester

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>
>
> why using the paint, this should also work with the presensitised clad
> boards. If you use a UV laser in the right wavelengt of the photoresist.
> I have being pondeingr over this myself, but never though to have a
> suitable beam that can be controlled in width from let say 0.1 to 0.5
> mm. I was even thinking of making my boards myself, by submerging the
> board completely in UV cureable photoresist, and then centrifuge it with
> high speed, so that the centrifugal force would make the layer of resist
> so equal as possibe. A brushless motor from old drive would be good for
> this, just have to make a reliable holder to keep the board from flying
> away...LOL.
>
> If you have more information about laser control, specialy the focus
> part, then please would you care to send it to me or post it here?
>
> thanks.
>
> Camillus
>>
>> On 12/9/2014 7:25:07 AM, Howard Chester howard.chester@...
>> [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:
>>
>>
>>
>> Jeff posted,
>> >I’m mentally exploring the idea of spray painting copper clad with
>> spray paint and drawing traces in the paint >with a laser. After the
>> laser, the board is then placed in etchant and the copper exposed by
>> the laser is >etched away. I understand this is possible with 20W
>> CO2 lasers by Youtube videos but has anyone >explored this with a
>> laser diode? Is the abundant ebay 445nm, 1W laser or the 808nm, 3W
>> laser up for >the task paint ablation?
>>
>> >Jeff
>>
>> Hello Jeff,
>> Just a few words of my musings...
>> Why not try to replace the high power LASER with a 400nm Ultra Violet
>> Soild State Laser Diode combined with a CD/DVD optic sled unit to
>> expose a UV resist PCB?
>>
>> A few advantages;-
>> 1) Lower power equals safer working enviroment
>> 2) Ease of use, the CD/DVD has a constant correcting focus control
>> loop. This would probably allow tracks in the sub mm range(0.2mm?). As
>> the visable red dot shining through the prism bounces back from the
>> PCB, mixing the nearly invisible UV beam on the opposite side of the
>> prism assembly by delivering the beam via a short lenght of cladded
>> fiber through the unpopulated side of the prism.
>> 3) A secondry advantage of the visible red dot is easy and accurate
>> registration when doing double sided PCB's.
>> 4) By tapping into the beam control(constant amplitude loop that
>> monitors the reflected beam power to compensate for impurities on
>> CD/DVD's (analog available at the red laser diode Anode-Cathode as a
>> varying Current through the red Diode)) would allow for a "Resist
>> thickness vs stepping motor delay" as well as slaving the UV LASER
>> drive current.
>> 5) Modern Micro-stepping Motor drive IC's would maximise the
>> resolution of the optics, unless you use the optics of the "sled"
>> control. In which case the resolution could be in the micro/nano meter
>> range.
>> 6) Cost, a UV LASER Diode module costs about 45 Bucks vs BIG bucks for
>> a large LASER, Drive Electronics and the delivery optics.
>>
>> / have pondered this concept for a while now but declining health has
>> force my early retirement/ and as such, my access to the nessessary
>> engineering tools.
>>
>> As stated, just my musings...
>> Good-luck with you project, chester
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
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> <http://www.avast.com/>
>
> This email has been checked for viruses by Avast antivirus software.
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>
>

I think there are two options to achieve a small spot size.  The first is a collimating lens.  The second is a fiber laser which is just a laser diode sold with a fiber attached.  I think both will achieve a spot size about 0.1mm (0.004”).  Can someone comment if this is correct?  Lenses are fiber lasers are sold on Ebay.  A microscope objective also works for a collimating lens.

 

I would like to avoid photoresist because –

No developing step

No preheating the developer

No developer required

No photoresist required

Quality of traces improves with no overdeveloping some areas and underdeveloping others

Cost is lower

No photoresist film application step – the most error producing step in the whole board making process from my experience

No laminator required for applying the photoresist

No modifying laminators for the correct photoresist application temperature

No guessing how good the photoresist is from age since the last time you used it

 

Jeff

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
Sent: Tuesday, December 09, 2014 12:57 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Re: laser ablation of paint on copper clad

 

 

why using the paint, this should also work with the presensitised clad boards. If you use a UV laser in the right wavelengt of the photoresist. I have being pondeingr over this myself, but never though to have a suitable beam that can be controlled in width from let say 0.1 to 0.5 mm. I was even thinking of making my boards myself, by submerging the board completely in UV cureable photoresist, and then centrifuge it with high speed, so that the centrifugal force would make the layer of resist so equal as possibe. A brushless motor from old drive would be good for this, just have to make a reliable holder to keep the board from flying away...LOL.

 If you have more information about laser control, specialy the focus part, then please would you care to send it to me or post it here?

 

thanks.

 

Camillus

On 12/9/2014 7:25:07 AM, Howard Chester howard.chester@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:

 

Jeff posted,

>I’m mentally exploring the idea of spray painting copper clad with spray paint and drawing traces in the paint >with a laser.  After the laser, the board is then placed in etchant and the copper exposed by the laser is >etched away.   I understand this is possible with 20W CO2 lasers by Youtube videos but has anyone >explored this with a laser diode?  Is the  abundant ebay 445nm, 1W laser or the 808nm, 3W laser up for >the task paint ablation?

 

>Jeff

 

Hello Jeff,

Just a few words of my musings...

Why not try to replace the high power LASER with a 400nm Ultra Violet Soild State Laser Diode combined with a CD/DVD optic sled unit to expose a UV resist PCB?

 

A few advantages;-

1) Lower power equals safer working enviroment

2) Ease of use, the CD/DVD has a constant correcting focus control loop. This would probably allow tracks in the sub mm range(0.2mm?). As the visable red dot shining through the prism bounces back from the PCB, mixing the nearly invisible UV beam on the opposite side of the prism assembly by delivering the beam via a short lenght of cladded fiber through the unpopulated side of the prism.

3) A secondry advantage of the visible red dot is easy and accurate registration when doing double sided PCB's.

4) By tapping into the beam control(constant amplitude loop that monitors the reflected beam power to compensate for impurities on CD/DVD's  (analog available at the red laser diode Anode-Cathode as a varying Current through  the red Diode)) would allow for a "Resist thickness vs stepping motor delay"  as well as slaving the UV LASER drive current.

5) Modern Micro-stepping Motor drive IC's would maximise the resolution of the optics, unless you use the optics of the "sled" control. In which case the resolution could be in the micro/nano meter range.

6) Cost, a UV LASER Diode module costs about 45 Bucks vs BIG bucks for a large LASER, Drive Electronics and the delivery optics.

 

 have pondered this concept for a while now but declining health has force my early retirement and as such, my access to the nessessary engineering tools.

 

As stated, just my musings...

Good-luck with you project, chester

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This email has been checked for viruses by Avast antivirus software.
www.avast.com

 

>
>
>Using photoresist and 20mW 405nm laser works nice.
>I use cheap ebay laser and got spot under 0.08mm in one direction
>and 0.1 in other (spot is oval not round.)

>Now I wait to get stronger laser to crank up speed.

>Slavko.

On 12/10/2014 1:46:29 AM, Slavko Kocjancic eslavko@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:

 

Using photoresist and 20mW 405nm laser works nice.
I use cheap ebay laser and got spot under 0.08mm in one direction and 0.1 in other (spot is oval not round.)
Now I wait to get stronger laser to crank up speed. Now I need aprox 15minutes for 100x160mm board raster scanned. I do try to implement solder resist too but need 10x more power. (I slow down scanning 10 times and paint solidify) but that's inpractical. Hope that with new laser I got solder resist curing under 10 minutes and photoresist sensitizing undef 5 minutes (speed of mechanic is limiting factor and laser driver too as frequency approach 1MHz.)

Slavko.


On 10. 12. 2014 06:43, 'Jeff Heiss' jeff.heiss@... [Homebrew_PCBs] wrote:

I think there are two options to achieve a small spot size.  The first is a collimating lens.  The second is a fiber laser which is just a laser diode sold with a fiber attached.  I think both will achieve a spot size about 0.1mm (0.004”).  Can someone comment if this is correct?  Lenses are fiber lasers are sold on Ebay.  A microscope objective also works for a collimating lens.

 

I would like to avoid photoresist because –

No developing step

No preheating the developer

No developer required

No photoresist required

Quality of traces improves with no overdeveloping some areas and underdeveloping others

Cost is lower

No photoresist film application step – the most error producing step in the whole board making process from my experience

No laminator required for applying the photoresist

No modifying laminators for the correct photoresist application temperature

No guessing how good the photoresist is from age since the last time you used it

 

Jeff

 

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
Sent: Tuesday, December 09, 2014 12:57 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Re: laser ablation of paint on copper clad

 

 

why using the paint, this should also work with the presensitised clad boards. If you use a UV laser in the right wavelengt of the photoresist. I have being pondeingr over this myself, but never though to have a suitable beam that can be controlled in width from let say 0.1 to 0.5 mm. I was even thinking of making my boards myself, by submerging the board completely in UV cureable photoresist, and then centrifuge it with high speed, so that the centrifugal force would make the layer of resist so equal as possibe. A brushless motor from old drive would be good for this, just have to make a reliable holder to keep the board from flying away...LOL.

 If you have more information about laser control, specialy the focus part, then please would you care to send it to me or post it here?

 

thanks.

 

Camillus

On 12/9/2014 7:25:07 AM, Howard Chester howard.chester@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:

 

Jeff posted,

>I’m mentally exploring the idea of spray painting copper clad with spray paint and drawing traces in the paint >with a laser.  After the laser, the board is then placed in etchant and the copper exposed by the laser is >etched away.   I understand this is possible with 20W CO2 lasers by Youtube videos but has anyone >explored this with a laser diode?  Is the  abundant ebay 445nm, 1W laser or the 808nm, 3W laser up for >the task paint ablation?

 

>Jeff

 

Hello Jeff,

Just a few words of my musings...

Why not try to replace the high power LASER with a 400nm Ultra Violet Soild State Laser Diode combined with a CD/DVD optic sled unit to expose a UV resist PCB?

 

A few advantages;-

1) Lower power equals safer working enviroment

2) Ease of use, the CD/DVD has a constant correcting focus control loop. This would probably allow tracks in the sub mm range(0.2mm?). As the visable red dot shining through the prism bounces back from the PCB, mixing the nearly invisible UV beam on the opposite side of the prism assembly by delivering the beam via a short lenght of cladded fiber through the unpopulated side of the prism.

3) A secondry advantage of the visible red dot is easy and accurate registration when doing double sided PCB's.

4) By tapping into the beam control(constant amplitude loop that monitors the reflected beam power to compensate for impurities on CD/DVD's  (analog available at the red laser diode Anode-Cathode as a varying Current through  the red Diode)) would allow for a "Resist thickness vs stepping motor delay"  as well as slaving the UV LASER drive current.

5) Modern Micro-stepping Motor drive IC's would maximise the resolution of the optics, unless you use the optics of the "sled" control. In which case the resolution could be in the micro/nano meter range.

6) Cost, a UV LASER Diode module costs about 45 Bucks vs BIG bucks for a large LASER, Drive Electronics and the delivery optics.

 

 have pondered this concept for a while now but declining health has force my early retirement and as such, my access to the nessessary engineering tools.

 

As stated, just my musings...

Good-luck with you project, chester

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This email has been checked for viruses by Avast antivirus software.
www.avast.com

 

This email has been checked for viruses by Avast antivirus software.
www.avast.com

On 10. 12. 2014 09:14, Cristian crissstian@... [Homebrew_PCBs] wrote:
> At 09:46 AM 10-12-14, you wrote:
>>
>> Using photoresist and 20mW 405nm laser works nice.
>> I use cheap ebay laser and got spot under 0.08mm in one direction
>> and 0.1 in other (spot is oval not round.)
> Let me know, please the eBay number. 0.08x0.1 is very good.
>
>> Now I wait to get stronger laser to crank up speed.
> Be careful that more power means more copper reflections=large traces.
>
>> Slavko.
> Cristian
>
>
>
> ------------------------------------
> Posted by: Cristian <crissstian@...>
> ------------------------------------
>
> 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
>
>
>
>

On 10. 12. 2014 09:14, Cristian crissstian@... [Homebrew_PCBs] wrote:
> At 09:46 AM 10-12-14, you wrote:
>>
>> Using photoresist and 20mW 405nm laser works nice.
>> I use cheap ebay laser and got spot under 0.08mm in one direction
>> and 0.1 in other (spot is oval not round.)
> Let me know, please the eBay number. 0.08x0.1 is very good.
>
>> Now I wait to get stronger laser to crank up speed.
> Be careful that more power means more copper reflections=large traces.
>
>> Slavko.
> Cristian
>
>
>
> ------------------------------------
> Posted by: Cristian <crissstian@...>
> ------------------------------------
>
> 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
>
>
>
>

>My laser is that cheapo...
>
>http://www.ebay.ie/itm/151023934656?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
>
>
>Will try with that when received
>http://www.ebay.ie/itm/161132483080?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
>
>
>Not yet decided to order 0.7W as is not cheap...

On 10. 12. 2014 10:24, Cristian crissstian@... [Homebrew_PCBs] wrote:
>
> No more than 120mW for uv photoresist exposure, otherwise you will
> experience strong reflections.
> Cristian
>
>
>

>With 100mW laser I
>need to switch it on and off at 1MHz rate.

>> With 100mW laser I
>> need to switch it on and off at 1MHz rate.
> BJT is slow. Use fets.

> Also, "pre-heat" the laser diode with some 10% current with a resistor.

>
>
> Why that speed? I guess you expose point by point.

>
> I suggest you to convert the normal Gerber output to HPGL (that means
> lines instead of points)
> and to use it as in a plotter. No speed problem here.

>
> I've bought such a program. If you think to go that way, you can mail
> me your Gerber and I'll send you
> back, for free, the converted HPGL.

> By your name you are from ex-Jugoslavia. I'm Rumanian.
> Cristian

What solder resist do you use?  Are you using photoresist as solder resist?

 

Jeff

 

I use locally produced photoresist (liquid) and striped out after etching by scrubbing.
For now I just apply rosin (colophony) dissolved in isopropil alcohol as it helps with soldering too and 10 years old boards seems like new.
But I do some tests with UV curable solder mask from ebay
http://www.ebay.ie/itm/180917181008?ru=http%3A%2F%2Fwww.ebay.ie%2Fsch%2Fi.html%3F_from%3DR40%26_sacat%3D0%26_nkw%3D180917181008%26_rdc%3D1

and works nice but need at least 10x more laser power to cure.
I tested to slow down motion 10 times but got some strange bubles in paint. Probably related with nitrogen exhaust from paint itself. But if I do it fast and do 10x repeat then harden as should. (I scan same line 10 times and after that advance to next line)
For now with laser I have is just inpractical as it take to long time.

Slavko.

Verry interesting, but I had one more question. Did you ever tried to cover the pcb with vinyl used by signmaking?

Wouldthe laser be able to cut ( burn ) true the vinyl. That would be awesome, then just laser the outline, etching and then laser the solder pads. Clean it all up and pcb is ready, with vinyl soldermask.

cb

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
>
>
>
>

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

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
>
>
>
>

> It's written in video description."

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
>
>
>
>



------------------------------------

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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
>
>
>
>

> I saw few attempts too.
> Well wraping pcb to drum is near inposible.
> Hello--

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

> -----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

> center of the pixels. How are the pixels in the bitmap mapped to their

> 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

> 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

> 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

> http://groups.yahoo.com/group/Homebrew_PCBs
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>
>
>
> ------------------------------------
> Posted by: "Jeff Heiss" <jeff.heiss@...>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and

> http://groups.yahoo.com/group/Homebrew_PCBs
> ------------------------------------
>
> Yahoo Groups Links
>
>
>

> 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
>> ------------------------------------
>>
>> 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: "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
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
> .
>

> 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
>

On 12/13/2014 11:06:25 AM, Slavko Kocjancic eslavko@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:

On 13. 12. 2014 11:39, 'Tony Smith' ajsmith1968@...
[Homebrew_PCBs] wrote:
> 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
>

The laser dot is just little under 1000dpi in size. But I have limited
on off timings so the width I can controll is about 700DPI. But this is
true only for rotation axis. I advance board for only 0.01mm each
revolution so there are plenty of overlap. And I do leave laser on if
there are more same dots in a row.

My preprocesor program just crunch the coordinates and make file stream
of '1' and '0' for laser for each 15us. The linuxcnc with component
'streamer' then stream this each 15us to the laser. And here is
bottleneck as I can't go faster (but I want) and I need to make some
special hardware to stream much faster than 15us/pulse.

I think to use some AVR with plenty of ram and to upload entire stream
on it, and after that just stream bits. At 1 bit per 1us the AVR will
work hard. But seems that static ram is just too small to fit entire
image, I will probably use dinamyc ram (4Mbits *4). As I calculated I
don't need to worry about refresh as cycling as streaming is fast
enought to keep memory refreshed. But need to cary refresh when data is
uploading and waiting start of operation where is enought time to proper
manage refresh cycle.



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>Hi, maybe you should consider double addressable ram, is a bit more expencive, but it can be written and read at the same time, ( has two address counters in it ), I'm not shure but they call it LIPO or something likethat. 
>Anyway it is sure fast enough and wile your avr is pumping bits in it the cnc can read them. It depends now on what you need be the fastest.

>
>
>cb
>
>
>On 12/13/2014 11:06:25 AM, Slavko Kocjancic eslavko@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:
>On 13. 12. 2014 11:39, 'Tony Smith' ajsmith1968@...
>[Homebrew_PCBs] wrote:
>> 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
>>
>
>
>The laser dot is just little under 1000dpi in size. But I have limited
>on off timings so the width I can controll is about 700DPI. But this is
>true only for rotation axis. I advance board for only 0.01mm each
>revolution so there are plenty of overlap. And I do leave laser on if
>there are more same dots in a row.
>
>
>My preprocesor program just crunch the coordinates and make file stream
>of '1' and '0' for laser for each 15us. The linuxcnc with component
>'streamer' then stream this each 15us to the laser. And here is
>bottleneck as I can't go faster (but I want) and I need to make some
>special hardware to stream much faster than 15us/pulse.
>
>
>I think to use some AVR with plenty of ram and to upload entire stream
>on it, and after that just stream bits. At 1 bit per 1us the AVR will
>work hard. But seems that static ram is just too small to fit entire
>image, I will probably use dinamyc ram (4Mbits *4). As I calculated I
>don't need to worry about refresh as cycling as streaming is fast
>enought to keep memory refreshed. But need to cary refresh when data is
>uploading and waiting start of operation where is enought time to proper
>manage refresh cycle.
>
>
>
>
>
>
>------------------------------------
>
>
>------------------------------------
>
>
>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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On 12/13/2014 5:49:32 PM, Harvey White madyn@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:

 

On Sat, 13 Dec 2014 14:40:06 -0600, you wrote:

>Hi, maybe you should consider double addressable ram, is a bit more expencive, but it can be written and read at the same time, ( has two address counters in it ), I'm not shure but they call it LIPO or something likethat. 
>Anyway it is sure fast enough and wile your avr is pumping bits in it the cnc can read them. It depends now on what you need be the fastest.

Another way is to multiplex the address and data from application to
application, so that half of the time, the AVR is writing to the RAM,
and the other half of the time, the CNC can read it.

This is relatively easy to do, but requires the memory to be twice as
fast as your cycle time, if not a bit faster for safety. I'd use a
CPLD or FPGA to do the multiplexing, just because it's easier. If you
don't have the tools to do this, then counters/registers and
multiplexers work just fine. You'll have to play games with the AVR
if you're using direct memory access, because the memory access cycle
is not absolutely in phase with the clock.

Just because you have the clocks for the processor and the clocks to
the CPLD in phase does not guarantee that the two requests would be
synchronized.

Your best bet would be to have the whole cycle time so short that the
processor can write at any time, then expect to get/write data
correctly.

Strangely enough, writing with using a port (Programmed I/O) is easier
to synchronize (you can loop and wait on a status) than direct memory
write/read synchronized to the processor clock. If your FPGA/CPLD
has dual port memory (Xilinx 3AN series do...) then this can help if
your assumed buffer size is small enough.

Harvey

>
>
>cb
>
>
>On 12/13/2014 11:06:25 AM, Slavko Kocjancic eslavko@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:
>On 13. 12. 2014 11:39, 'Tony Smith' ajsmith1968@...
>[Homebrew_PCBs] wrote:
>> 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
>>
>
>
>The laser dot is just little under 1000dpi in size. But I have limited
>on off timings so the width I can controll is about 700DPI. But this is
>true only for rotation axis. I advance board for only 0.01mm each
>revolution so there are plenty of overlap. And I do leave laser on if
>there are more same dots in a row.
>
>
>My preprocesor program just crunch the coordinates and make file stream
>of '1' and '0' for laser for each 15us. The linuxcnc with component
>'streamer' then stream this each 15us to the laser. And here is
>bottleneck as I can't go faster (but I want) and I need to make some
>special hardware to stream much faster than 15us/pulse.
>
>
>I think to use some AVR with plenty of ram and to upload entire stream
>on it, and after that just stream bits. At 1 bit per 1us the AVR will
>work hard. But seems that static ram is just too small to fit entire
>image, I will probably use dinamyc ram (4Mbits *4). As I calculated I
>don't need to worry about refresh as cycling as streaming is fast
>enought to keep memory refreshed. But need to cary refresh when data is
>uploading and waiting start of operation where is enought time to proper
>manage refresh cycle.
>
>
>
>
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> On Sat, 13 Dec 2014 14:40:06 -0600, you wrote:
>
>> Hi, maybe you should consider double addressable ram, is a bit more expencive, but it can be written and read at the same time, ( has two address counters in it ), I'm not shure but they call it LIPO or something likethat.
>> Anyway it is sure fast enough and wile your avr is pumping bits in it the cnc can read them. It depends now on what you need be the fastest.
>
> Another way is to multiplex the address and data from application to
> application, so that half of the time, the AVR is writing to the RAM,
> and the other half of the time, the CNC can read it.
>
> This is relatively easy to do, but requires the memory to be twice as
> fast as your cycle time, if not a bit faster for safety. I'd use a
> CPLD or FPGA to do the multiplexing, just because it's easier. If you
> don't have the tools to do this, then counters/registers and
> multiplexers work just fine. You'll have to play games with the AVR
> if you're using direct memory access, because the memory access cycle
> is not absolutely in phase with the clock.
>
> Just because you have the clocks for the processor and the clocks to
> the CPLD in phase does not guarantee that the two requests would be
> synchronized.
>
> Your best bet would be to have the whole cycle time so short that the
> processor can write at any time, then expect to get/write data
> correctly.
>
> Strangely enough, writing with using a port (Programmed I/O) is easier
> to synchronize (you can loop and wait on a status) than direct memory
> write/read synchronized to the processor clock. If your FPGA/CPLD
> has dual port memory (Xilinx 3AN series do...) then this can help if
> your assumed buffer size is small enough.
>
> Harvey
>
>
>>
>>
>> cb
>>
>>
>> On 12/13/2014 11:06:25 AM, Slavko Kocjancic eslavko@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:
>> On 13. 12. 2014 11:39, 'Tony Smith' ajsmith1968@...
>> [Homebrew_PCBs] wrote:
>>> 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
>>>
>>
>>
>> The laser dot is just little under 1000dpi in size. But I have limited
>> on off timings so the width I can controll is about 700DPI. But this is
>> true only for rotation axis. I advance board for only 0.01mm each
>> revolution so there are plenty of overlap. And I do leave laser on if
>> there are more same dots in a row.
>>
>>
>> My preprocesor program just crunch the coordinates and make file stream
>> of '1' and '0' for laser for each 15us. The linuxcnc with component
>> 'streamer' then stream this each 15us to the laser. And here is
>> bottleneck as I can't go faster (but I want) and I need to make some
>> special hardware to stream much faster than 15us/pulse.
>>
>>
>> I think to use some AVR with plenty of ram and to upload entire stream
>> on it, and after that just stream bits. At 1 bit per 1us the AVR will
>> work hard. But seems that static ram is just too small to fit entire
>> image, I will probably use dinamyc ram (4Mbits *4). As I calculated I
>> don't need to worry about refresh as cycling as streaming is fast
>> enought to keep memory refreshed. But need to cary refresh when data is
>> uploading and waiting start of operation where is enought time to proper
>> manage refresh cycle.
>>
>>
>>
>>
>>
>>
>> ------------------------------------
>>
>>
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>>
>>
>> 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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>
>
> ------------------------------------
> Posted by: Harvey White <madyn@...>
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>
>
> I was thinking that the propeller would be a good device for this
> project, it hass 10 cogs ( independent cores you may say ) and one
> master that controls the IO I think. I'm just stating what I remember
> from reading. The only drawback is the language,, not a common ....
>
> cb
>>

The Bungard drum plotter has laser spot size of 0.005mm/0.0002inches.  This is a resolution of 5,000 dpi.  The laser inside is a red 670nm laser.  How do they achieve this?  What laser and lenses are used?

Is red sensitized photoresist film common?  Where can it be purchased?

Photoplotter

Jeff

On 12/19/2014 10:43:29 AM, jeff.heiss@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:

 

The Bungard drum plotter has laser spot size of 0.005mm/0.0002inches.  This is a resolution of 5,000 dpi.  The laser inside is a red 670nm laser.  How do they achieve this?  What laser and lenses are used?

Is red sensitized photoresist film common?  Where can it be purchased?

Photoplotter

Photoplotter

Filmstar-Plus is the name of the next generation of our bitmap photoplotter series. Optimized for inhouse production of high end film layouts at reasonable p...

View on bungard.de

Preview by Yahoo

Jeff

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On 12/19/2014 10:43:29 AM, jeff.heiss@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:



The Bungard drum plotter has laser spot size of 0.005mm/0.0002inches. This is a resolution of 5,000 dpi. The laser inside is a red 670nm laser. How do they achieve this? What laser and lenses are used?



Is red sensitized photoresist film common? Where can it be purchased?



Photoplotter <http://bungard.de/index.php?option=com_content&view=article&id=43&Itemid=60&lang=english>



<http://bungard.de/index.php?option=com_content&view=article&id=43&Itemid=60&lang=english> Image removed by sender. image

<http://bungard.de/index.php?option=com_content&view=article&id=43&Itemid=60&lang=english> Photoplotter

Filmstar-Plus is the name of the next generation of our bitmap photoplotter series. Optimized for inhouse production of high end film layouts at reasonable p...




<http://bungard.de/index.php?option=com_content&view=article&id=43&Itemid=60&lang=english> View on bungard.de

Preview by Yahoo






Jeff



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On 12/19/2014 10:43:29 AM, jeff.heiss@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:

The Bungard drum plotter has laser spot size of 0.005mm/0.0002inches. This is a resolution of 5,000 dpi. The laser inside is a red 670nm laser. How do they achieve this? What laser and lenses are used?

Is red sensitized photoresist film common? Where can it be purchased?

Photoplotter <http://bungard.de/index.php?option=com_content <http://bungard.de/index.php?option=com_content&view=article&id=43&Itemid=60&lang=english> &view=article&id=43&Itemid=60&lang=english>



<http://bungard.de/index.php?option=com_content <http://bungard.de/index.php?option=com_content&view=article&id=43&Itemid=60&lang=english> &view=article&id=43&Itemid=60&lang=english> Image removed by sender. image

<http://bungard.de/index.php?option=com_content <http://bungard.de/index.php?option=com_content&view=article&id=43&Itemid=60&lang=english> &view=article&id=43&Itemid=60&lang=english> Photoplotter

Filmstar-Plus is the name of the next generation of our bitmap photoplotter series. Optimized for inhouse production of high end film layouts at reasonable p...



<http://bungard.de/index.php?option=com_content <http://bungard.de/index.php?option=com_content&view=article&id=43&Itemid=60&lang=english> &view=article&id=43&Itemid=60&lang=english> View on bungard.de

Preview by Yahoo




Jeff

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[Non-text portions of this message have been removed]

On 12/19/2014 10:43:29 AM, jeff.heiss@... [Homebrew_PCBs] <homebrew_pcbs@yahoogroups.com> wrote:

The Bungard drum plotter has laser spot size of 0.005mm/0.0002inches. This is a resolution of 5,000 dpi. The laser inside is a red 670nm laser. How do they achieve this? What laser and lenses are used?

Is red sensitized photoresist film common? Where can it be purchased?

Photoplotter <http://bungard.de/index.php?option=com_content <http://bungard.de/index.php?option=com_content&view=article&id=43&Itemid=60&lang=english> &view=article&id=43&Itemid=60&lang=english>



<http://bungard.de/index.php?option=com_content <http://bungard.de/index.php?option=com_content&view=article&id=43&Itemid=60&lang=english> &view=article&id=43&Itemid=60&lang=english> Image removed by sender. image

<http://bungard.de/index.php?option=com_content <http://bungard.de/index.php?option=com_content&view=article&id=43&Itemid=60&lang=english> &view=article&id=43&Itemid=60&lang=english> Photoplotter

Filmstar-Plus is the name of the next generation of our bitmap photoplotter series. Optimized for inhouse production of high end film layouts at reasonable p...



<http://bungard.de/index.php?option=com_content <http://bungard.de/index.php?option=com_content&view=article&id=43&Itemid=60&lang=english> &view=article&id=43&Itemid=60&lang=english> View on bungard.de

Preview by Yahoo




Jeff

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