Laser engraving with CNC USB controller

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knightlander
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Joined: Fri Sep 09, 2016 1:58 am

Laser engraving with CNC USB controller

Post by knightlander » Mon Sep 12, 2016 3:38 am

I am new to the forum. I am using PicEnrave Pro 5 software to laser engrave my images.

Has anyone used cnc usb controller ( http://planet-cnc.com/hardware/#products-hardware board.) I am able to get the laser to work, but unable to get good results for photo engraving. Here are the setting I am using. I am using output pin two for spindle control.

Thanks for any help!
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laser control.PNG
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LTEPM
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Location: no where near the end of the rainbow

Re: Laser engraving with CNC USB controller

Post by LTEPM » Mon Sep 12, 2016 4:19 am

Which controller are you using?

Do you have a current limiting board for your laser?

What power is your laser?

knightlander
Posts: 4
Joined: Fri Sep 09, 2016 1:58 am

Re: Laser engraving with CNC USB controller

Post by knightlander » Tue Sep 13, 2016 1:08 am

I am using the laser kit J Tech Photonics (2.8 W 445nm laser 2.5amp). I have the postive wire coming from output #2 going to H2 control input signal on laser driver board. Ground wire from output to control input ground.

No I am not using a current limiting board. I am using cnc usb contoller software.
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Mk 3-4 controller.PNG
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picengravertoo
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Re: Laser engraving with CNC USB controller

Post by picengravertoo » Tue Sep 13, 2016 4:51 pm

Are you just using M3/M5 to control the laser on/off to engrave photos, or S spindle speed commands with the PWM output to the J-Tech laser driver? I'm not familiar with the CNC controller software your using, but does it execute the commands in real time without dwelling? You may need the PicConvert DAC/PWM board to modulate the laser driver for varied intensity control.

https://jtechphotonics.com/?product=dac ... rter-board
Shapeoko 2 Laser Diode Engraver-Analog/TTL/PWM
PicEngrave Pro 6 Image to Gcode for grbl/Mach3 controllers-Spindle/Laser
PicLaser: Image to Gcode With Editor
PicSender: Streams grbl Raster/Vector Gcodes
https://www.picengrave.com

knightlander
Posts: 4
Joined: Fri Sep 09, 2016 1:58 am

Re: Laser engraving with CNC USB controller

Post by knightlander » Wed Sep 14, 2016 1:31 am

I am using (s) spindle speed with PWM. Could it be possible to have the wrong PWM frequency setting?
I am attaching part of my program to see if this will help.
Thank you for all your help!

( PicEngrave Pro 5 - for MS Windows US Version )
( Date/Time: 09-13-2016 at 21:15:33 )
( Image File: 9-11 343 )
( Analog + Feed Rate )
( 25.0% Feed Rate Change )
( 90.0000 inches/min. )
( Image size in inches: 4.596w x 6h )
( Pixel Resolution: 0.006 inch )
( Line Spacing: 0.006 inch )
( Max. Cut Depth: 255.0000 inch )
( Min. Cut Depth: 10.0000 inch )
( 3rd Axis Safe Position: 0 inch )
( Start Position: image bottom left )
( Horizontal Axis Offset: 0 inches )
( Vertical Axis Offset: 0 inches )
( Engraving Angle: Vertical )
( Spindle On/Off Enabled )
( Inch Mode )
( X Axis Align 0 )
( Y Axis Align 0 )
G20
F90
G01 S0
F90
G01 X0 Y0 S0.0000 F90
M03
X0 Y-0.006
X0 Y0 S236.7451 F69.1
X0 Y0.006 S237.7059 F69
X0 Y0.012 S238.6667 F68.9
X0 Y0.018 S238.6667 F68.9
X0 Y0.024 S236.7451 F69.1
X0 Y0.03 S235.7843 F69.2
X0 Y0.036 S234.8235 F69.3
X0 Y0.042 S234.8235 F69.3
X0 Y0.048 S233.8627 F69.4
X0 Y0.054 S233.8627 F69.4
X0 Y0.06 S233.8627 F69.4
X0 Y0.066 S233.8627 F69.4
X0 Y0.072 S233.8627 F69.4
X0 Y0.078 S234.8235 F69.3
X0 Y0.084 S234.8235 F69.3
X0 Y0.09 S235.7843 F69.2
X0 Y0.096 S236.7451 F69.1
X0 Y0.102 S234.8235 F69.3
X0 Y0.108 S235.7843 F69.2
X0 Y0.114 S237.7059 F69
X0 Y0.12 S235.7843 F69.2

picengravertoo
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Re: Laser engraving with CNC USB controller

Post by picengravertoo » Wed Sep 14, 2016 8:55 pm

The required PWM frequency for the J-Tech driver is 1Khz. Using S commands could dwell on every line of gcode because of the spindle spin up delay and it could be very difficult to laser engrave images successfully.

Does the X&Y axis's move very slow and laser burning images dark when running that gcode file? Is that the problem your having?

Does your CNC controller program use the G64 Constant Velocity command? I noticed you don't have that selected in PicEngrave.
Shapeoko 2 Laser Diode Engraver-Analog/TTL/PWM
PicEngrave Pro 6 Image to Gcode for grbl/Mach3 controllers-Spindle/Laser
PicLaser: Image to Gcode With Editor
PicSender: Streams grbl Raster/Vector Gcodes
https://www.picengrave.com

knightlander
Posts: 4
Joined: Fri Sep 09, 2016 1:58 am

Re: Laser engraving with CNC USB controller

Post by knightlander » Thu Sep 15, 2016 2:33 am

I will check the frequency in my controller software.

My X & Y axis's move normally. The problem I was having is the different shading of the picture.

My controller does use G64 command, but I did not noticed I did not have it checked in PicEngrave software. I will try another picture to see if the the G64 fixes my issues.

I looked at the board information you posted. I do have a fourth axis on my machine, would you recommend the board from J-Tech or put a Digital MA3 electro-mechanical rotary encoder coupled to the a axis. Then connect the wires from the encoder to laser driver board?

picengravertoo
Posts: 155
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Location: Florida
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Re: Laser engraving with CNC USB controller

Post by picengravertoo » Thu Sep 15, 2016 9:23 am

Ok, the problem your having could be as simple as a focal distance and lens focusing issue. We use a 3" focal height and then use a piece of black anodized aluminum to focus on to see when the spot is as small as possible. Also, the J-Tech lens does not focus the beam to quite a round spot, so you may need to experiment with different engraving angles.
Shapeoko 2 Laser Diode Engraver-Analog/TTL/PWM
PicEngrave Pro 6 Image to Gcode for grbl/Mach3 controllers-Spindle/Laser
PicLaser: Image to Gcode With Editor
PicSender: Streams grbl Raster/Vector Gcodes
https://www.picengrave.com

JTechPhotonics
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Location: Houston, TX
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Re: Laser engraving with CNC USB controller

Post by JTechPhotonics » Fri Sep 16, 2016 2:32 pm

HI John,

I noticed in the spindle settings for the PlanetCNC board that you have the "Delay" set to "1" for on and off. This will cause a delay every time the spindle speed (laser power is adjusted) and will pause the machine with the laser on. This will make the laser burn longer than it is supposed to and cause the image to be black. Try and see if you can change this to "0" for on and off. This should eliminate extra delay introduced by the software.

Best Regards,
Jay
J Tech Photonics, Inc.
Laser Upgrade your Shapeoko: http://jtechphotonics.com/?page_id=1100

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