How to connect laser module to cnc sheild v3.0

[sankajalakshan]

I want to add 2.5w ttl/pwm laser module to my corexy plotter.

https://goo.gl/images/2awCuV

1. What is the best method TTL or PWM?
2. What is the Wiring digram of TTL and PWM?
3. How to supply power?

Please help...

[arkypita]

1. TTL and PWM means the same (different way to call the "on-off" tecnology)
2. See grbl website, not LaserGRBL one
3. Same as 2

[StuartB4]

If it's a Protoneer Shield look here:
https://forum.protoneer.co.nz/index.php
https://forum.protoneer.co.nz/viewforum.php?f=6

Also, what version of GRBL are you running? V3 boards are only compatible with GRBL 0.8

[sankajalakshan]

Im using v3.0 cnc sheild and grbl 1.1f (latest version) . Currently i made a 4xidraw corexy pen plotter and it's working well. So i need to improve it adding a laser module.

[StuartB4]

Do you have an Arduino Uno. If so then I think you can connect the yellow PWM wire from the Laser to the Z+ limit switch connector on the CNC Shield. That Z+ pin on the shield should follow the tracks on the shield to Pin 11 on the Arduino. That will supply the PWM signal for the laser power modulation.
The reason is that with GRBL 1.1 they switched Pins 11 and 12. Pin 12 is now the limit switch pin and Pin 11 is the variable spindle / laser power pin.
But you will have to check that first preferably with a multimeter.

The Black and Red wires of the laser should go to (I think) 12V @2 amps or more, more is ok but it will probably need at least 2 amps.

Also you will have to set these 3 highlighted settings in GRBL settings in LaserGRBL.
Set them to the same as mine here:

[sankajalakshan]

Thanks StuartB4.

When we have the 3 pin module (VCC, GND, PWM), I have to connect VCC into external 12v 2+A power source (+) and GND into external 12v 2+A power source (-) and PWM into cnc sheild Z+.

Is that correct?

Do i need to connect the GND into (-) of the external power source and the GND of the arduino borad/cnc sheild?

[StuartB4]

Yes that should work as long as the Z+ on the CNC shield is connected to pin 11 on the Arduino when the shield is plugged in to it. Yes you can make a connection from the - on the power supply to the GND on the Arduino, forgot to mention that.

[sankajalakshan]

Thanks a lot

[sankajalakshan]

I have some issues to clarify.
Please help.
If i want to engrave a wood can i use 500mw laser? If it is, when i using a 2500mw laser, that wood will engrave deeper than 500mw laser.

Is there any code or method to control the power of 2500mw laser. Like when i need to engrave something lightly and when i need to engrave somthing hardly can i adjust the power of laser?

[StuartB4]

Yes you can burn wood with a 500mw, and yes the more powerful the laser the more it will burn.
If you are using LaserGRBL to burn then the settings for the laser power are in the GCode when it is generated.
So you can use a 2.5 watt laser but only burn lightly.
It's to do with the S setting and the speed your machine moves.
It can have a high speed (mm per minute) setting but if the S for the laser power value is high it will still burn more than if you have a high speed and low power S setting.

The settings can be changed when you import your image in to LaserGRBL.

The settings are then inserted in to the GCode when it's generated. So when you have your image imported and the settings how you think are ok you can save the GCode by clicking File, Save Program in LaserGRBL.
Then you end up with something like this example:

Saving the program allows you to edit the code later if the burn was not as good as you thought.
The Speed setting is the F100 or whatever you set yours to.
All the S's are the laser power values. This particular code was for doing a greyscale image using Line to Line Tracing option so there are varying laser power levels.

This example code is for a Vector engraving so the S power level is fixed @ 30, and the speed is set to 700
G90
G0 X0 Y0
M5 S30
F700
G0 X16.021 Y13.713
M3
G1 X16.058 Y13.825
G1 X16.584 Y13.713
G1 X17.11 Y13.6
G1 X17.459 Y13.6
G1 X17.809 Y13.6
G1 X17.779 Y13.775
G1 X17.75 Y13.95

[sankajalakshan]

Thanks a lot.....

[StuartB4]

These were all burned with LaserGRBL.
The ones with the overlaying squares and the chess board one were all done with the same laser power using a 300mw red laser but at different speeds between 80 and 200 mm per minute.

The greyscale images were done with a 2 watt blue laser. The pencil is just so you get an idea of how small they are.
My machine is made from old DVD drives so it only has a maximum work size of 40 x 40 mm's

[sankajalakshan]

Thanks a lot. If anything to add to learn, please be kind enough to update me. And you are explaining this well. Thanks again.

[sankajalakshan]

i made this and laser not turn on by the lasergrbl. however after connecting the power to the laser module when pushing the switch laser on but not burning.

[StuartB4]

Do you have PWM mode enabled in LaserGRBL settings?

[sankajalakshan]

yes it also enabled.

[StuartB4]

Can you check the config.h file in the Arduino Libraries folder.
If you look at this picture you can see where it should be on your computer.
You may have a different user name to mine but it should be in the same place.

I edit this file with Notepad++ which is a free text editor and better than notepad as it gives you line numbers at the begining of the lines.

When you find config.h scroll down to line number 339 and make sure there are no //'s in front of the # symbol. If there are then you have to remove them, save the file and recompile GRBL and re-upload it to the Arduino.

[sankajalakshan]

i checked, it is also not commented. i measure the voltage by multi meter on D11(Z+) pin and GND, it shows the maximum voltage is 4.35v.

[ingrc91]

good day to all.
I have a problem with the laser configuration, I will send you an image of your circuit

it stays on

[StuartB4]

Which version of GRBL are you using?

[ingrc91]

[ingrc91]

the laser stays on does not turn off

[ingrc91]

Can you help me please
I'm just starting in the world of laser cnc

[StuartB4]

Check your config.h file in the Arduino Libraries.

I edit this file with Notepad++ which is a free text editor and better than notepad as it gives you line numbers at the begining of the lines.

When you find config.h scroll down to where it says #define VARIABLE SPINDLE and make sure there are no //'s in front of the # symbol. If there are then you have to remove them, save the file and recompile GRBL and re-upload it to the Arduino.

Also check in GRBL Configuration in LaserGRBL to make sure you have $31 and $32 set correctly.
$31=0
$32=1

[arkypita]

First, check proper working of your driver.
Detach pwm cable from shield, probe it to 5v and gnd. Laser should turn on and off respectly.

[ingrc91]

Primero, verifique el correcto funcionamiento de su conductor.
Desconecte el cable pwm del blindaje, pruebe a 5v y gnd. El láser debe encenderse y apagarse respetuosamente.
I did the same thing but only turn on the fan and when it has just carried out the trajectory it keeps on the laser fan but not the laser.

[ingrc91]

[arkypita]

did the same thing but only turn on the fan and when it has just carried out the trajectory it keeps on the laser fan but not the laser.

So: you confirm that pwm pin is not controlling laser on/off?

If yes, your is an hardware problem. Could you post a picture of your boars and wiring?

[fantilator]

Change #define variable_spindle to #define variable_spindle true and recompile.

[ingrc91]

![image](https://user-images.githubusercontent.com/44658063/47865127-6657df80-ddc9-11e8-92c6-5c8ef21b9459.pn

[StuartB4]

Your 2 pin laser needs more power than that supplied by the Z+/- pin.
That is the PWM signal that comes from pin 11 on the Arduino, not a power pin.

You need a seperate laser driver board that has PWM connection.
Then you can connect a 2 pin laser to the output of the driver board and the laser is switched on with the PWM signal that goes from the Arduino to pin Z+/- on the shield and in to the PWM or TTL pin on the driver board.

The laser driver board will either have it's own power supply to power the laser or it will get it from the main control board of the engraver.
In your case with the Arduino UNO you need to power the laser driver board seperately because the Arduino can not supply the power needed for the laser.

[csanii123]

Your 2 pin laser needs more power than that supplied by the Z+/- pin.
That is the PWM signal that comes from pin 11 on the Arduino, not a power pin.

You need a seperate laser driver board that has PWM connection.
Then you can connect a 2 pin laser to the output of the driver board and the laser is switched on with the PWM signal that goes from the Arduino to pin Z+/- on the shield and in to the PWM or TTL pin on the driver board.

The laser driver board will either have it's own power supply to power the laser or it will get it from the main control board of the engraver.
In your case with the Arduino UNO you need to power the laser driver board seperately because the Arduino can not supply the power needed for the laser.

Thanks Stuart. I was starting to suspect that maybe not enough power was being output. I'll have to go through my "collection" and see if I have a driver board I can use.

[StuartB4]

Just need something like this.

[StuartB4]

Oh yea, you can use either Z+ or Z- as they are both connected together on the shield circuit.

[csanii123]

Just need something like this.

Could i use a relay like below to provide more power ?
https://www.banggood.com/5V-Relay-1-Channel-Module-One-Channel-Relay-Expansion-Module-Board-p-91800.html?cur_warehouse=CN&rmmds=search

[StuartB4]

The link you posted is not working. The link that shows up is this one https://github.com/arkypita/LaserGRBL/issues/url
Also the link you posted above earlier is not working, it's the same as the second one.

You could use a relay to switch the laser on but it will just be on or off, nothing in between, no variable power control.

[csanii123]

I fixed my previous msg links (I hope). So I think you are saying if I just want On/Off then a Relay will handle it but if I want to be able to control the laser strength I need a control board. If I use PWM with the relay that will just have the laser at full strength but with varying delay between the on/off ?

[gmmanonymus111]

If the relay you linked worked that way, the clicking sound would drive you mad, and the relay would die really quickly. Let's say the relay turns on at 3v. When your pwm reaches the 3v duty cycle, the relay closes, and your laser turns on at max power (if you have a 5v power supply), and remains at full power even is the duty cycle goes above 3v (like 4.4v or 5v). If it drops below 3v, the relay opens and your laser turns off completely, no in between values.
And a laser driver is strongly advised, as you can kill your laser by plugging it to an unregulated power supply.

[csanii123]

Just need something like this.

If I use a laser driver like this does it convert the modulation input into varying voltages so that the laser strength is adjustable ?
I am assuming the max current is set by the variable resistor. So does the current get varied by the circuit based on the PWM input ratio of ON to OFF ? ie. a cycle with half ON and half OFF would be a current/voltage of 50%, a cycle with 75% ON and 25% OFF would be 75%, etc ? Is there a doc somewhere that you can point me to regarding the laser driver ? I went searching and although I could find some for sale, none really gave any info other than what to connect to each spot on the board.

[tornadomag]

I've set up the steps per mm in Lightburn but when I go to "move" and set a distance of 30mm, the moving speed is either very very slow OR the axis moves towards the opposite direction. Is this something fixable? Did I flash the arduino the wrong way?
Plus, I've set the machine dimensions to 500mm x 500mm but the axes move forever unless I hit stop

[csanii123]

I've set up the steps per mm in Lightburn but when I go to "move" and set a distance of 30mm, the moving speed is either very very slow OR the axis moves towards the opposite direction. Is this something fixable? Did I flash the arduino the wrong way?
Plus, I've set the machine dimensions to 500mm x 500mm but the axes move forever unless I hit stop

I am not using Lightburn but I did have a problem using UGS when I first started. I had the FEEDRATE set to 1 so I would hear the motor but could see no movement. Once I increased it to 100 the motor actually would visibly move. Not sure if Lightburn has a similar setting but if it does try increasing it. As for the movement in wrong direction, did you set your HOME position properly or possibly invert your wires to your motor so they are running in reverse ?

[tornadomag]

Before doing the axis calibration, the motors moved fast enough (more or less like my prusa i3 during rapids). Also the direction confusions don't happen every time. If an axis goes the wrong way and I hit stop and then hit the same move icon again, it goes where it's supposed to. This happens 3 times out of 5.

[gmmanonymus111]

@csanii123 Yep, that board should change your laser's power according to the PWM signal received from your arduino.
Here's a video, it might help you understand it a little more.

@tornadomag Could you tell us more about your setup (engraver type, belt or bolt driven system etc and your $$ GRBL settings)?
EDIT: Maybe start a new seperate discussion, so we won't spam this closed issue with irrelevant conversation

[tornadomag]

@tornadomag Could you tell us more about your setup (engraver type, belt or bolt driven system etc and your $$ GRBL settings)?

It's an openbuilds acro 55 belt driven, using arduino uno r3 and cnc shield v3. Drivers are A4988.
I just watched a video on youtube (have no idea which one) on how to flash grbl onto the uno...

[gmmanonymus111]

@tornadomag In that case, I suggest to take a look here. That FAQ might help a lot on compiling/flashing/setting up GRBL for your machine. If you have other questions about setting up your machine, please start a new discussion.

[StuartB4]

You can flash it in LaserGRBL. On the Tools menu.

[rahularepaka]

Hey Guys,

Hi, I am currently bought this laser E7480 Laser Head 12V 5A and I don't have a PWM controller but I have a Power Supply Step Down which converts from 220V to 12V 30A.

https://www.ebay.com/itm/500mW-EleksMaker-405-445NM-Blue-Module-2-54-3P-TTL-PWM-Modulation-For-E8V0-/133472115886

I bought the same laser and I wanted to control it without the PWM controller, can I control it using an Arduino

Will this Wiring work? where the green cable goes into the Arduino port

[gmmanonymus111]

@rahularepaka Since CNC Shield uses the Arduino pins in a way (it just comapcts them a little for ease-of-use), you can skip it if you want, using directly an Arduino. Arduino can generate PWM signals for you, which is then used by your laser driver board (the one on top of that laser module). Same as it would be with a CNC shield.

[rahularepaka]

@gmmanonymus111
so this would work, right?

But the laser only takes in 12 V at 5A but I am supplying 12V at 30A, won't it be a problem? and any idea what is voltage can the Laser module on the top take in cuz I couldn't find any documentation on it?

Thanks

[gmmanonymus111]

That would work okay.

If the PSU can produce greater current than the laser can take is not a bad thing, in fact, it is good (it could even operate your steppers on top of your laser module), so the 30A should be fine. Vattage in the other hand, should always be the same. So a 12V laser module should be always operated by a 12V PSU.
This laser module is a 12V one, from it's description:

Input Voltage: 12V 5A

This means you can connect that PSU directly, as shown by your picture.
As for the actual laser diode, it is most likely operates on a different voltage, but your laser driver does this kind of hard work for you.

[rahularepaka]

@gmmanonymus111 Thanks for the quick reply!

So I will do this wiring then! and the point of the laser is a different purpose it is to destroy weeds in my garden

So, I will be writing a code with Analog Write Function and I will try it tomorrow and let you if it works?

[gmmanonymus111]

Sounds good to me, I'm interested in the results ^^

[csanii123]

I have my laser "cutter/engraver" moving properly and laser turns ON/OFF.
The problem is the laser doesn't actually cut the paper or engrave although other people say they have gotten it to do so.
Is there something below I should change to make it cut/engrave ?

Parts:
Arduino + CNC Shield
Software: GRBL v1.1h
Laser: https://www.banggood.com/Focusable-200-250mW-650nm-Laser-Module-Red-Dot-Laser-Generator-Diode-Replacement-Mini-DIY-Engraver-p-955966.html?rmmds=myorder&cur_warehouse=CN
Laser Driver: https://www.ebay.ca/itm/143257071978?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649
X/Y motors: Zyltech 1.5A 0.42 N.m stepper motors

Arduino is powered by USB connection to computer
CNC Shield is powered by 12V/30W power supply
Laser is connected to a laser driver which is also powered by same power supply
The analgue IN on the laser driver is connected to the Z+/GND endstop on the CNC shield
The X/Y motors work properly and the laser turns ON/OFF when sent GRBL commands.
If I send GRBL "S" commands the laser gets brighter with higher numbers
I focused the laser to the smallest sized "dot" that I could.
The laser was about 7cm from the paper - I then moved it closer and refocused to small "dot" again
For the test cut I am just enabling the laser at full strength - M3 S255.
I am not sending GRBL commands to the motors.

GRBL settings:
**** Connected to COM3 @ 115200 baud ****
Grbl 1.1h ['$' for help]

$$
$0 = 10 (Step pulse time, microseconds)
$1 = 25 (Step idle delay, milliseconds)
$2 = 0 (Step pulse invert, mask)
$3 = 0 (Step direction invert, mask)
$4 = 0 (Invert step enable pin, boolean)
$5 = 0 (Invert limit pins, boolean)
$6 = 0 (Invert probe pin, boolean)
$10 = 1 (Status report options, mask)
$11 = 0.010 (Junction deviation, millimeters)
$12 = 0.002 (Arc tolerance, millimeters)
$13 = 0 (Report in inches, boolean)
$20 = 0 (Soft limits enable, boolean)
$21 = 1 (Hard limits enable, boolean) -->>>>enabled this so max size limit since didn't add limit switches yet
$22 = 1 (Homing cycle enable, boolean)
$23 = 7 (Homing direction invert, mask)
$24 = 25.000 (Homing locate feed rate, mm/min)
$25 = 500.000 (Homing search seek rate, mm/min)
$26 = 250 (Homing switch debounce delay, milliseconds)
$27 = 5.000 (Homing switch pull-off distance, millimeters) --->>>>Updated this so would disengage after homing
$30 = 255 (Maximum spindle speed, RPM) --->>>>Need to set to 255 for LaserGRBL control ****
$31 = 0 (Minimum spindle speed, RPM)
$32 = 1 (Laser-mode enable, boolean) --->>>>Need to set to 1 for laser mode*****
$100 = 171.000 (X-axis travel resolution, step/mm) --->>>>Part of calibration testing
$101 = 158.000 (Y-axis travel resolution, step/mm) --->>>>Part of calibration testing
$102 = 250.000 (Z-axis travel resolution, step/mm)
$110 = 700.000 (X-axis maximum rate, mm/min) --->>>>Set this for faster movement
$111 = 500.000 (Y-axis maximum rate, mm/min) --->>>>Left as default since less distance right now
$112 = 500.000 (Z-axis maximum rate, mm/min)
$120 = 10.000 (X-axis acceleration, mm/sec^2)
$121 = 10.000 (Y-axis acceleration, mm/sec^2)
$122 = 10.000 (Z-axis acceleration, mm/sec^2)
$130 = 220.000 (X-axis maximum travel, millimeters) --->>>>Set this since no max limit switch added
$131 = 150.000 (Y-axis maximum travel, millimeters) --->>>>Set this since no max limit switch added
$132 = 200.000 (Z-axis maximum travel, millimeters)

[gmmanonymus111]

@csanii123 I'm not sure a 200-250mW laser is able to cut white paper. IMO you'll need at least a 500mW one (correct me here if I'm wrong), or use an IR one, as paper can be cut more easily with those. If you want to cut, place your laser as close to the paper as possible (regarding focus).
Side note, hope you meant 12V/30A instead of 12V/30W. If no, the PSU is too weak to provide current for the steppers and the laser when you engrave anything.
Side note II: Use soft limits instead of hard limits if you don't have limit switches.

[csanii123]

Other people on the Banggood website (where I bought the laser) say they have this cutting/engraving. I reduced the distance from 7cm to about 2cm but still no luck. I did mean 12V/30W as that is what the power supply is rated at. Perhaps that is the problem... I need a larger amperage power supply for the 12V laser driver. I'll try connecting the power supply directly to the laser driver and see if without the motors that works.
P.S. I have physical limit switches at the HOME location but none at the Xmax,Ymax locations so I am using soft limits for those.

[csanii123]

Ok I swapped the 12V/30W power supply with a 600W PC power supply so should be more than enough power.
Arduino is still powered via USB from computer
12V from PC P/S is powering the CNC Shield
5V from PC P/S is powering the laser directly (ie. no laser controller in use so I can't control laser ON/OFF but this should rule out laser not getting enough power)
Laser is 2cm above the paper and focused to as small a dot I can get (this is as close as I could get for a focused dot)
Feed rate is set to F20 in GRBL so it is moving very slow
Paper color seems to matter
The laser housing gets very hot

Results:
Black kids construction paper - seems to cut well
Blue kids construction paper - seems to cut partially
White printer paper - does not cut and in some spots has a slight burn mark

a) Other than getting a more powerful laser is there anything else I can do to make this better for cutting paper ?
b) Other than getting a more powerful laser is there anything else I can do to make this faster for cutting paper ?
c) Is there something I need to do to make it able to cut white printer paper ?
d) Is there something I need to do so the laser doesn't run as hot ?

[gmmanonymus111]

Paper color seems to matter

Darker colors tend to absorb visible light better, while lighter ones reflect it

The laser housing gets very hot

That's expectable, it might need a heatsink. If you have a used CPU heatsink, you can drill it. For this laser, it is sufficient.

a) Other than getting a more powerful laser is there anything else I can do to make this better for cutting paper ?

Unless the current regulator inside the laser housing has a potentiometer on it, nope.

b) Other than getting a more powerful laser is there anything else I can do to make this faster for cutting paper ?

Same as above

c) Is there something I need to do to make it able to cut white printer paper ?

Same as above, or you could get a more powerful laser (for reference, my NEJE 1500mW laser (output power, not optical power, that is waaaaay lower) was able to cut through white paper at 100 mm/min)

d) Is there something I need to do so the laser doesn't run as hot ?

Heatsink, either a passive pre-made one for these kind of lasers (watch out for the diameter), or as written abowe, drill a hole in a used CPU heat sink (+attach vent for active cooling, if needed, but that's a bit overkill) like this one:

[bcabral]

About the laser TTL pin and arduino, as I understand arduino pin PWM output is from 0 to 5V, but the laser specs states its PWM/TTL pin as being 0 to 12V

If I understand things correctly, arduino feeding "full power" (5V) to the laser, it will be only at 41% of capacity because 5V is 41% of 12V (the maximum the laser accept). Arduino at 2.5V (half-power) will be just a bit more of 20% of the laser capacity (2.5V of 12V)

Is this understanding correct? If so, do I need some kind of module to upscale the arduino output from 0-5V to 0-12V? If so, any recomendations on such a module?

(I asked the laser manufacturer and they said the need for 12V is correct and state the board they sell outputs 0 to 12V, but I am using arduino, cnc shield and GRBL)

[csanii123]

If your laser is from 0-12V then you likely need a module in between. Also the Arduino can't output high current to power the laser so again you want a module in between to boost the current to the laser.

[Erkanbaba52]

I could not connect the laser module with 0-12 v pvm input to ender3 pro, which works with 24 v. Arduino produces 0-5 V PVM. The last user named csanii123 mentioned a module. Is this dc-dc converter module?