Laser ON/OFF (M3/M5) dont work? about lasergrbl HOT 26 CLOSED

Yes. You can make it work though by using a laser driver like this. You wont need the relay set-up either.

Available on eBay at various prices.

The top red circle is the Laser Voltage Adjuster, the bottom one is the Laser Current Adjuster.

The Laser Tube connections top right are for a normal 2 wire laser.

The bottom right connector is where you connect 1 wire from Z+ or Z- on the CNC Shield,
and 1 wire from a Ground pin on the shield. The Z+ and Z- are both connected together on the shield so it does'nt matter which one you use, the ground pin can be any of the row of pins in the row next to it.

It has 2 x 12volt power connectors but you only need to use 1.
Either the black barrell connector for just 12v DC or the white connector
above it which can be 12v AC or DC.
The board has a rectifier built in to change AC to the DC that it needs.

It's the one I use on my new machine.

from lasergrbl.

In order to use all of LaserGRBL feature, your engraver must supports laser power modulation through gcode "S command".

LaserGRBL use "S command" to reproduce pure black or white image as well as greyscale image.
"S command" control power modulation: the ability of arduino to generate a PWM signal that control the instant power of laser by switching it very fast through its driver "TTL" pin (M3/M5 could not switch laser so fast). I.e. S0 mean laser power = 0%, S255 mean laser power 100%, and S128 mean laser power 50% etc...

Indeed, to engrave an image composed only by the colors black and white would suffice the M3 and M5 commands, but to take full advantage of laser potential, the PWM modulation is really important.

from lasergrbl.

Please look at those link to read about power modulation and how to activate in your board.
http://blog.protoneer.co.nz/grbls-pwm-functionality-how-to-control-a-laser-or-variable-speed-spindle/
https://github.com/gnea/grbl/wiki/Connecting-Grbl#grbls-pins (PWM use pin 11)

How to modify driver to support laser power modulation:
https://forum.arduino.cc/index.php?topic=192733.0
https://forum.allaboutcircuits.com/threads/ttl-modulated-driver-for-laser.31275/
http://forums.reprap.org/read.php?133,703931

In addition version 1.1 grbl has added an important new feature for those who use the laser, which is precisely the "laser mode". To read anything more informed about it here:
https://github.com/gnea/grbl/wiki/Grbl-v1.1-Laser-Mode#laser-mode-overview

If you follow my instructions and you will activate the laser power modulation you will find a tool much more useful than what you have now.

Best regards

from lasergrbl.

Hi,
thanks.
at the moment i only can turn the laser on and off (have to reasearch on which way i can add a pwm inkl so DDL)

from lasergrbl.

Maybe I could add a config switch for who does not have PWM ability that replace all S command with M3/M5 command based on threshold. I added it on dev roadmap.

from lasergrbl.

Ok, thanks.

from lasergrbl.

So,
i tried to use an PWM like this:

I normally use the 3055 on D12 to turn the laser on and off.

When i laser something it looks like it works (a bit).
But:

1. I dont get the full power
2. I cant enable the laser, only when it "draw something" it goes on. I cant turn it on manually to focus the laser for example.

(Just for Info)

from lasergrbl.

N° 1
You can not get full power even if you connect the control pin to fixed +5V?
S255 must produce a PWM modulation of 100% time +5V out of pin 11, so it is equivalent to a +5V when you issue a S255 command.

I suppose you don't have an oscilloscope to test signal on D11 but you could try to do some diagnoses with a led+resistor on D11
You can also do some measure with a multimeter on transistor Vce to see if you loose some power on transistor.

Also remove 10uF capacitor near Laser Diode. PWM control need to be fast in on/off operation, and capacitor add charging/discharging times when transistor open/close to ground.

P.s. i usually prefer MOSFET as switch when i design PWM circuit, but transistor could be ok too.

N° 2
gnea/grbl#72
#19

from lasergrbl.

Hi, no i dont have a oscilloscope.
When i connect the E3055 to D12 and disable #define VARIABLE_SPINDLE than i get full power.

I anyway want to test a MOSFET or a 555 timer as next step, greetings.

from lasergrbl.

Hi! Any news? Did you get it working with full power?

from lasergrbl.

Hi,
I have not ordered the things yet.
I wait to make a bigger order cause of the shipping costs (shipping is more expensive than the part itself^^)

from lasergrbl.

I know, it's a common problem.

By the way I don't know if LM317 could be easly used in a TTL circuit.
http://laserpointerforums.com/f67/pwm-ttl-controlled-driver-56027.html

Maybe it's easier to buy a ready laser driver with ttl like this one: http://www.ebay.co.uk/itm/12V-TTL-200mW-To-2W-445nm-450nm-Laser-Diode-LD-Power-Supply-Driver-Board-/322453276000?hash=item4b13b68560:g:a2UAAOSwhQhYyCzg

from lasergrbl.

In these days I made a version that allows to use LaserGRBL on machines that do not have the PWM control. I have not had a chance to test it properly, but if you want to try it and tell me if it works you can download it from here: https://github.com/arkypita/LaserGRBL/releases/tag/v2.5.1-pre

from lasergrbl.

I will test it net weekend.

Greetings.

from lasergrbl.

Hi,
i testet the Version.
But why i can only use Vectoring and this 1bit thing when i disable the PWM Support?
With this i 1 Bit it all time looks a but broken.



( a bit to slow -.- ^^)

Greetings.

from lasergrbl.

The function called "Line To Line line tracing" is used to produce grayscale images modulating power, so it cannot be used for hardware setup without power modulation. So I have removed the option for PWM-less hardware.

1 bit dithering try to reproduce eye grayscales effect by creating a black points map. The dithering alghoritm could add some artifacts when white pixels are not "pure white".

http://lasergrbl.com/usage/raster-image-import/dithering-tool/
http://codegolf.stackexchange.com/questions/26554/dither-a-grayscale-image

But... your image is not a grayscale! Is a pure black logo. The best result for pure black logos is obtained with vectorization + filling. Try this combination, result will be OK!

from lasergrbl.

I have a similar issue, I have been able to connect. I can move the steppers however laser stays on from start to finish. if its plugged in the computer it is on regardless of having lasergrbl started or not. ive adjusted $32=1. unchecked the pwm box. didnt have this issue until i uploaded grbl v1.1.hex but i had no connectivity before that. ive ran the laser with t2laser however subscription issues rendered my computer without a hardware number. ive tried S0 m5

from lasergrbl.

Hi joncarns.
What setup do you have?
Which laser, laser driver, Arduino Type etc,
Do you have any pics of the wiring / connections of the machine.

from lasergrbl.

Hi All,,
I have the same problem.
When I set M3 S255 the laser is turned on but without power..
I need to send M3 S2500 to have a powerful laser.
but, for me looks something is wrong because PWM should be from 0 to 255 only
It is very hard to control the power, any one has an idea?

from lasergrbl.

You could try changing the PWM Frequency settings in the cpu_map.h file in Arduino Libraries.

First make a copy of the original cpu_map.h file and put it somewhere safe, in case it needs to be replaced.

Open cpu_map.h with a text editor and find the section I have highlighted in the image below.
If the line numbers are different to the ones in my image it does'nt matter, just find the same highlighted section. This is the section you need:

// Prescaled, 8-bit Fast PWM mode.
#define SPINDLE_TCCRA_INIT_MASK ((1<<WGM20) | (1<<WGM21)) // Configures fast PWM mode.
// #define SPINDLE_TCCRB_INIT_MASK (1<<CS20) // Disable prescaler -> 62.5kHz
//#define SPINDLE_TCCRB_INIT_MASK (1<<CS21) // 1/8 prescaler -> 7.8kHz (Used in v0.9)
// #define SPINDLE_TCCRB_INIT_MASK ((1<<CS21) | (1<<CS20)) // 1/32 prescaler -> 1.96kHz
#define SPINDLE_TCCRB_INIT_MASK (1<<CS22) // 1/64 prescaler -> 0.98kHz (J-tech laser)

Change line 141 (4th line down in that section) by REMOVING // from the begining of the line to uncomment it.

Change line 143 (6th line down in that section) by ADDING // to comment it out.

It should then look like the image below.

Click File menu in your text editor and select Save so it overwrites the original in the library.
Recompile GRBL and re-upload to the Arduino for the changes to work.

from lasergrbl.

@facumaster

from lasergrbl.

G'day All,

@StuartB4 I have read in other responses that you have a dvd\cd setup as do and I.
And I am running a Arduino Uno + CNC Shield V3 on the Z+ Stop for laser on, just using a 200-250mW 650nm Laser. So my question is:
Is it possible to run a PWM setup on my system?
I have the PWM ticketed on but when I use m4 the laser just does not turn on and on m3 it works.

Cheers

from lasergrbl.

It should work as it is providing your laser driver is PWM/TTL compatible.
Which laser driver do you have?
Which version of GRBL do you have?

from lasergrbl.

from lasergrbl.

Ummm so i am sort of not using one..... could this be the root cause??

I have the Arduino Uno + CNC Shield V3 to a relay to the laser......

from lasergrbl.

Thanks for the quick reply! Ill keep you posted once the driver arrives in the mail ;)
Also wow what a great setup, nice work @StuartB4

Thanks again

from lasergrbl.