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Author Topic: The Laser Project.  (Read 853713 times)

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Re: The Laser Project.
« Reply #480 on: August 15, 2011, 10:53:18 AM »
Tweakie,
I am having trouble with my small laser setup using the Digit Trigger (?).  When set active low, the laser stays on full time (even when no axis movement) - when active low the laser is off.  I am using a 1 watt laser diode - homemade TTL driver.  It works fine when using the Z axis direction signal, and I get excellent wood burns with sharp line starting and ending points.  I am using pin #9 output for both modes, and just change pin assignments in Config>Ports and Pins to test - no wiring changes.  I suspect that I may have not set something correctly in Mach3, but cannot find it.  I have tried both yours and Art's version of the Laser/Impact plug-in with same results.  The plug-in seems to work OK when I load an image and start Mach3 - just no laser pulsing response.

All advice greatly appreciated.
Best Regards,
John Champlain

Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #481 on: August 15, 2011, 12:01:10 PM »
Hi John,

Sounds as though you have the 'Ports and Pins' set up correctly and that the problem may be feedrate related.

The plugin's output on the digital trigger is dependant on the Kernel speed, the image pixel value and the axis feedrate - currently, the Kernel speed should be 25000Hz  and the axis feedrate set in motor tuning somewhere between 4,000 and 20,000 mm/min with the plugin feedrate set somewhere above 300 mm/min.
If your laser diode has good response then you are in with a chance but it is pretty much 'trial and error' here.

As an example, my true X Axis feedrate is 4,500 mm/min and I set the plugin feedrate to 15,000 mm/min and this just squeaks in at the bottom end of the requirements for a CO2 tube which has really poor response at the lower end of the power scale.

Experiment with the feedrates and let me know if this resolves the problem.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: The Laser Project.
« Reply #482 on: August 15, 2011, 02:16:57 PM »
Tweakie,

Thank you.  I have (had) two problems.  First, I discovered a minor wiring mistake on my driver board.  Corrected it and the Digit Trigger signal is now controlling my laser diode.  I'm not sure why it was working with the Z axis direction signal and not the Digit Trigger before - just luck I guess.  Secondly, as I'm sure you already know, because of the low power laser diode, I have to run at too low of a feed rate (7 to 10 inch/min.) for the current Laser/Impact software to work.  I will have to stay with my present 'full on-full-off' method of diode operation for now.   Later, I may dive into the source code to see if I can adapt it more to my circumstances.

My Best to You,
John Champlain
Finally going to drop some pictures....
« Reply #483 on: August 15, 2011, 04:24:50 PM »
Tweakie - I know I've been saying I'm going to post things, and it's taken me forever.  I'm usually farting around on my laser trying to figure out the best feeds / speeds for everything instead of taking pictures of stuff... :)  Sorry about that.

Anyhow - here's two small things I've done.  the picture of my boy running actually looks a lot better in person than it does in the picture.  Also, balsa seems to be a horrible wood to engrave in - it's so grainy.  It produces some pretty nice contrast though.  It was done at 375 in/min (10,000 mm/min) at about 22% power, which was probably set a little too high.



The second image was some text I engraved into some scrap acrylic I had lying around.  Same settings, basically, but bumped laser power up to about 50%.  Came out good.  I did start finding out that I really need to turn off my air assist when I'm engraving, it condenses the acrylic vapors and leaves a fine powder all over the rest of the engraving, which ends up leaving a ghosting effect around the letters, all in the same direction, since the air is blowing out of the nozzle.  Once I turned the air assist off, the problem went away.  I also noticed that when I'm engraving in beechwood that I was having the same issue.  Although, not leaving the air assist on led to the dust collecting all over the print and staining the really light areas when I brushed it off.  I might actually make a two-way air assist for my laser, one that blows out, and one that vacuums.

Re: The Laser Project.
« Reply #484 on: August 16, 2011, 12:03:31 AM »
something's weird - it's not letting me post again for some reason.  Going to give it one more shot.

Anyhow - fired up the rotational engraving attachment this afternoon, and put a Newcastle logo on a glass.  The logo is about 3" tall.  It's much more detailed in person than it is in this picture, the skyline in the star and the borders on the letters all stand out.  Pretty cool stuff.  Used the engraving plugin to do it.

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Re: The Laser Project.
« Reply #485 on: August 16, 2011, 01:26:23 AM »
Hey naPS,

That's brilliant, looks like you are really getting the hang of it. Thanks for posting the pictures (we all love pictures).

(with deep engraving of wood / plastic I use paper transfer tape [used for vinyl sign application] - this prevents the surface smoke discolouration and is easily removed after the work is completed  ;) ).

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

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Re: The Laser Project.
« Reply #486 on: August 18, 2011, 07:42:13 AM »
This was the prototype, laid out using Microsoft Powerpoint, saved as a .jpg then run through the Impact / Laser plugin.
It has poor resolution but this could be improved by using a larger canvas size in Powerpoint then scaling down the final work.

Should cause a smile  ;D

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: The Laser Project.
« Reply #487 on: August 18, 2011, 08:34:20 AM »
  :) ;D :)
 ..... hip boots recommended, chest waders preferred.
 :)

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Re: The Laser Project.
« Reply #488 on: August 18, 2011, 11:57:57 AM »
  :) ;D :)
 ..... hip boots recommended, chest waders preferred.
 :)


 ;D
----------------------------------------------------------------------
Just because I'm a Global Moderator, don't assume that I know anything !

Dave->    ;)
Re: The Laser Project.
« Reply #489 on: August 18, 2011, 01:07:48 PM »
Tweakie,
What version of C++ are you using to modify the Art's plug-in?  I tried MS C++ 2008, but get an error on one file after C++ 2008 converts the source code from an earlier version.   I am not familiar with C++, so learning as I go.

Thanks,
John Champlain