Author Topic: The Laser Project.  (Read 792089 times)

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Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #880 on: November 04, 2014, 04:10:01 AM »
Hi Zann,

The version shown on my website works ‘as is’ without the additional switch panel (which was added later to enable extra menu items selection).

As mentioned above by Daniel, the Arduino based design by Art may be a much easier project for controlling your J48 – I am certainly following it with great interest and hope to get it working with my CO2 laser in the not too distant future.

Tweakie.
« Last Edit: November 12, 2014, 02:52:51 AM by Tweakie.CNC »
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline zann68

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Re: The Laser Project.
« Reply #881 on: November 16, 2014, 11:49:28 AM »
Looking into that as well. Thanks Guys

Offline Tokamak

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Re: The Laser Project.
« Reply #882 on: November 21, 2014, 01:52:53 PM »
Tweekie,
Help!!
After reading your build I decided to install an 80W laser on my MechMate. All works fine except turning on the Laser from Mach3.

I cannot get pin 16 to go active. Configured output #1, Port 1, Pin 16

My G code looks like this:

N70G00G20G17G90G40G49G80
N80G70G91.1
N90 (End Mill {0.006 inch}MDF)
N100G94
N110F40.0
N120G00X0.1001Y0.1072M10P1
N130G1M11P1
N140G1Y0.8572M11P1
N150G2X0.1314Y0.8885I0.0313J0.0000
N160G1X0.6314M11P1
N170G2X0.6626Y0.8572I0.0000J-0.0313
N180G1Y0.1072M11P1
N190G2X0.6314Y0.0759I-0.0313J0.0000
N200G1X0.1314M11P1
N210G2X0.1001Y0.1072I0.0000J0.0313
N220G00M10P1
N230G00X0.0000Y0.0000
N240M30
%

Mach3 Ver R3.043.066

I gotta be missing something simple.



Offline Tokamak

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Re: The Laser Project.
« Reply #883 on: November 21, 2014, 02:57:41 PM »
Tweekie,
Sorry for the hijack. Digging further I found a charge pump issue disabling the outputs on my PMDX board. Laser works!
Tokamak

Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #884 on: November 22, 2014, 01:50:26 AM »
I am pleased you found the problem.  ;)


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

Offline sitzme

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Re: The Laser Project.
« Reply #885 on: December 09, 2014, 07:55:09 PM »
"Well, after a bit of experimentation, I think I can now safely say that the Mach3 Impact / Laser plugin can be used with low power diode lasers."
"If there is any interest in this, I would be pleased to provide the details of just how it was accomplished."

I am trying to get a KaleCNC diode laser working with the plugin.  It works in gcode and when using the plugin I do get pulses but not enough power to mark.  I am interested in how you got it to work.
Thanks for your efforts on this topic in general.

Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #886 on: December 10, 2014, 03:35:15 AM »
Hi Sitzme,

The plugin’s ‘fire pulse’ width is limited (it is essentially the axis step pulse) and as feed-rate is reduced the spacing between pulses increases thus producing the ‘lack of power’ problem you are experiencing.

My solution was to use an external microprocessor (PIC chip) to digitally detect the ‘fire pulse’ then extend it’s width. The prototype is a bit crude (based on a partially populated circuit board designed for my RF laser controller) and whilst I have every intention to refine this design and post it as a project, like most things, work interferes with play-time and it has been pushed to the back of the queue. The design could, I am sure, be simplified (by not having the display) as the microprocessor automatically stores the last setting (for future use) and it is easy enough to set-up by experimentation with a test sample. It requires no changes to the machine as it connects in series with the 25 way LPT cable and is just used when required.

Some while back another member posted an analogue design for pulse stretching and this works well but had limitations on the range of available pulse widths so I opted for a digital solution which can easily extend the fire pulse width right up to the start of the next pulse no matter how slow the feed-rate. His design is here http://www.prutchi.com/2012/02/04/co2-laser-engravercutter-addition-to-a-cnc-retrofitted-sieg-x2-mini-mill/


I am working on another project at present and this will probably keep me busy until the springtime but if you can wait until then I will post full constructional details of a re-designed pulse extender before the summer.

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

Offline sitzme

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Re: The Laser Project.
« Reply #887 on: December 10, 2014, 06:59:27 AM »
Thanks Tweakie.  I understand the work/play issue.  Would it work to slave the unused B axis with X at a ratio and fool Mach3 into seeing a high pulse rate for the X axis but put out a reduced rate to actually drive the axis?  I am going to look at this tonight but have to go make a living now. ;^)

Offline sitzme

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Re: The Laser Project.
« Reply #888 on: December 10, 2014, 04:13:03 PM »
Please disregard most of my last post.  Mach3 does not support gear ratios on slaved axis.  Having dug a bit more (someone correct me if wrong) it appears that the engraving plugin outputs a frequency with a 40ms pulse width and the diode laser TTL needs a PWM signal.  Either a software change/addition to the plugin or additional hardware is needed to use a diode laser if I understand.  Given the availability of low cost, higher power diodes these days, there will probably be more interest.  The PWM works great if you treat the laser as a spindle so hopefully someone will figure out a way to do it in software for the plugin.  Would it be possible to use an Arduino Uno to convert from pulse frequency to PWM in this instance?

Offline ART

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Re: The Laser Project.
« Reply #889 on: December 10, 2014, 04:38:06 PM »
Hi:

 Check the laser control panel thread in the forum at gearotic.com for information on such a project for mach4. The box there creates a PWM
signal for cutting or engraving photos..

Art