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Author Topic: The Laser Project.  (Read 855366 times)

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Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #300 on: December 21, 2010, 11:15:40 AM »
Hi Josh,

As far as I know there are no manuals or guides but it is simple enough to use it is really just a matter of trial and error.

Output from the plugin is on the 'digital trigger' and this can be configured within Mach to any output pin# of your choice. The output power from the plugin is related to axis speed and it may take a while to get this just right but that's it really.

Good fortune with your project.

It would be really nice if you would start another thread with details and pictures of your project and the progress you make.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: The Laser Project.
« Reply #301 on: December 21, 2010, 01:22:31 PM »
Just so I understand, with the plugin you are doing raster engraving where the laser varies the power level based on the bit depth of each pixel in the image as it scans back and forth along the x axis?

What type of signal are you using to tell the laser how much power to put out? 0 to 5 volt analog signal or a PWM signal?

Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #302 on: December 22, 2010, 02:35:23 AM »
Hi Josh,

The output from the plugin is a short duration pulse (40uS) it is the pulse repetition frequency that varies and this is in turn related to the feedrate. I am not sure this helps but the signal I am using to tell the laser how much power to put out is PRF.
I will be back on the project again in the new year but I am documenting the Synrad laser control here http://www.cooperman.talktalk.net/files/28.htm

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

Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #303 on: December 30, 2010, 08:51:27 AM »
A little bit more progress on the Synrad RF laser controller. After spending some time with the software trials I think I have now finalized the required layout for the circuit board. Nothing too fancy, just the basics.
This is the isolation routed PCB waiting for it's complement of components.

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

Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #304 on: December 31, 2010, 07:10:50 AM »
Managed to get most of the components (the essential ones at least) soldered on to the new PCB.
Now to test it out.

The IC bottom right is type 74LS08 manufactured in Portugal by Texas Instruments and looking at this picture, I just noticed the date code which is May 1981 !!  Texas certainly make stuff that lasts  ;)

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

Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #305 on: January 08, 2011, 01:19:33 PM »
For anyone considering building their own RF Laser controller / interface for use with Mach3 I have now posted my draft constructional details which may be of interest - Circuit diagram, PCB track layout, PCB component layout, PCB isolation routing GCode and the PIC programing Hex code. These can be downloaded from here http://www.cooperman.talktalk.net/J48.zip  It is early days yet and there is bound to be more revisions to the firmware but this link should always point to the current version.

Tweakie.



Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: The Laser Project.
« Reply #306 on: January 29, 2011, 11:23:29 AM »
Hello Tweakie and others!

I've been following this thread for a while now with great interest.

I've recently got a Synrad J48-2 and tested it yesterday with the controller of your design. Thank you for sharing!  :D

Here is a picture from it.


It says V16.1 when I turn it on.

I have some questions about the controller that is unclear to me.
1. Is there a tickle pulse even when I turn the encoder to ==OFF== mode?
2. From what I understand, the red LED on the J48-2 is supposed light dimly when it get the tickle pulse. Now it light up first at 1% PWM. And I've tried to get some light by changing the trimpot.
3. Do you change the frequency by pushing the encoder?

Best Regards
/Isak Nordell
Sweden

Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #307 on: January 30, 2011, 03:36:31 AM »
Hi Spruft,

Great work my friend that looks really good.

Obviously the controller is still under development and there will be some more changes to the firmware before I am finally happy with its operation. Version 16.1 is the current version.
I just don’t get enough time to work on this project so, like all my projects, progress is slow but sure.

1) In the OFF position there is no tickle pulse and the laser cannot be triggered (fired). The lasers red LED will be extinguished.
2) With the controller set to anything but OFF the laser’s red LED will glow dimly (after the lasers internal 5 second warm up delay) to indicate that a tickle pulse is present and that it is safe to fire the laser. Be careful adjusting the pulse width trim pot as tickle pulses wider than 1uS can cause the tube to start emitting a low level beam without actually having been triggered. (Currently the trim pot range is approx 0 to 2uS). With the controller switched to OFF the laser’s red LED will extinguish indicating that no tickle pulse is present.
3) Initially the frequency was changed by pushing the encoder, as you suspected, but I have a lot more work to do on this function because just changing the frequency without taking other factors into consideration enables the laser, in some circumstances, to be operated outside of it's comfort zone. So to be safe the frequency is currently fixed at 5kHz which is Synrad's recommended operating PFR.

Current work in progress:-
The development firmware now uses the encoder push function to switch between 5.0% steps and 0.5% steps so there are now190 possible settings between 0.5% and 95.0%.
Provision was made on the original PCB to add a pair of push switches (on a piggy back board) and these will be used to set other functions such as ‘last setting memory’, ‘store’ and PRF frequency settings etc. Full details of any updates will, of course, be posted.

Good fortune with your laser project and please keep us all posted with details of your progress and lots of pictures please (we all love pictures).

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: The Laser Project.
« Reply #308 on: January 30, 2011, 07:34:47 AM »
Thanks for the support Tweakie!

to switch between 5.0% steps and 0.5% steps
Haha I didn't notice it. Took a long time to get to 95% sometimes :D


A picture from the back. Currently working on the electronics.

Offline Tweakie.CNC

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Re: The Laser Project.
« Reply #309 on: January 30, 2011, 08:14:34 AM »
Wow, that looks like a real good sturdy construction.

It may be helpful so I have attached the V16.2 firmware which includes the 5.0 and 0.5 step sizes (switched by clicking the encoder push). This version has not been fully tested yet but looks good so far.

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