laser module TTL vs PWM

[nicolasdb]

Ok, Houston, we have a problem.

I order a second minilaser diode for fabmob but I was not please with the first one and I order the same used by bemaker this time. The machine is arrived, it's mounted but the laser module is lost somewhere.
Hopefully, I bought earlier another laser module as safety parts.
and because it's never easy and never work on the first attempt, connectors don't fit.

It's same same as the first (I was thinking)

But with Eleksmaker, it's a 3pin cable for the same module but like this.

The control board is the "SW-LD62 v2"
And I found this part.

Description:
This PWM TO TTL laser module is design for EleksMaker series machine and its controller board.
But it can also be used for other DIY machine which need to change TTL modulation.

Specification:
Power port size: 5.5*2.1mm
Working voltage: DC 12V
Woring power: >2A

Eleksmaker use the mana board controler.

The other is laseraxes board.

Seems less good than the other. And the power supply connector is a bit loose, it doesn't match the size of the power supply (2.5mm vs 2.1mm probably, tssss)
But have 2 place to connect laser, depending of the laser power. both 2pins.
note: I have a second mana board... ^^

So my question is simply, "what about unsolder 2pin connector and solder 3pin connect instead?" Right?

[nicolasdb]

last thing is the first laser module doesn't have the board, it's directly connected to the controler board laseraxe.
https://www.aliexpress.com/store/product/ZONESUN-Engraving-Machine-Laser-axe-405nm-2500mW-DIY-Desktop-Mini-Laser-Engraver-Laser-Cutter-Etcher-17X20cm/4425009_32894209182.html

[nicolasdb]

Here's the response from AliExpress shop gktools. Yeaaaaah China!

Hi， Nicolas,
We are very sorry for the delivery delay, I will call the express company, then I will reply you.
The 2p2p laser can used for the control board, if you can change the pin connector.
Sincerely!
Jamie.

[nicolasdb]

Connector changed from 2p2p to 3p. C

Careful to the poles...

I didn't had special connetors. ^^
Red wire on VCC

Match poles from controller. 12V/GND/PWM

[nicolasdb]

Still a problem with eleksmaker and chinese Arduino + laserweb.
=> BSOD with windows 7,8,10.
Bug with ch340 USB chipset.... Working fine with linux.

What is this ArduinoClone? usb chip CH340x
Original is usb chip FTDI
https://www.exp-tech.de/plattformen/arduino/4450/arduino-nano

Bon, Bsod, j'ai perdu ma doc sur le fabmob10.

https://www.pihomeserver.fr/en/2018/02/17/raspberry-pi-gravage-laser-cnc-eleksmaker-a3-pro/

[nicolasdb]

rapidement
https://www.youtube.com/watch?v=oXHmOdObTvw

• download hex not repo from grbl gnea
  https://github.com/gnea/grbl

• flash on arduino with Xloader, mastaeasy
  https://github.com/gnea/grbl/wiki/Flashing-Grbl-to-an-Arduino

• laserweb
  200x130
  power 1000 vs 255

check EEprom setings via "$$"

• check laser mode "$"+
  "32","Laser-mode enable","boolean","Enables laser mode. Consecutive G1/2/3 commands will not halt when spindle speed is changed."

• fine tune acceleration X,Y

"120","X-axis acceleration","mm/sec^2","X-axis acceleration. Used for motion planning to not exceed motor torque and lose steps."
"121","Y-axis acceleration","mm/sec^2","Y-axis acceleration. Used for motion planning to not exceed motor torque and lose steps."
"122","Z-axis acceleration","mm/sec^2","Z-axis acceleration. Used for motion planning to not exceed motor torque and lose steps."

• fine tune step/mm

"100","X-axis travel resolution","step/mm","X-axis travel resolution in steps per millimeter."
"101","Y-axis travel resolution","step/mm","Y-axis travel resolution in steps per millimeter."
"102","Z-axis travel resolution","step/mm","Z-axis travel resolution in steps per millimeter."

actual
X: 10mm = 31mm
step = 250

$100, $101 and $102 – [X,Y,Z] steps/mm
Grbl needs to know how far each step will take the tool in reality. To calculate steps/mm for an axis of your machine you need to know:
    The mm traveled per revolution of your stepper motor. This is dependent on your belt drive gears or lead screw pitch.
    The full steps per revolution of your steppers (typically 200)
    The microsteps per step of your controller (typically 1, 2, 4, 8, or 16). Tip: Using high microstep values (e.g., 16) can reduce your stepper motor torque, so use the lowest that gives you the desired axis resolution and comfortable running properties.
The steps/mm can then be calculated like this: steps_per_mm = (steps_per_revolution*microsteps)/mm_per_rev

Compute this value for every axis and write these settings to Grbl.

[nicolasdb]

https://github.com/gnea/grbl/wiki/Grbl-v1.1-Configuration#quick-guide-to-setting-up-your-machine-for-the-first-time

[nicolasdb]

note concernant elekslaser little sebastian

16 Octobre

• il manque des "spacers" et la carte controleur est courbée, so bad on so many levels.
  Les spacers en nilon sans dans la boite, ils doivent être installé.
  le circuit semble être dessiné pour se placer à la ligne plus bas.

• Check écart entre les profils alu, check la mise à l'équère et le serrage des vis de structure.
  Les petites équères métal côté intérieur ne sont pas serré, aucun.
  ça va poser problème dans les transports, vibrations, perte de vis, qui vont se retrouver n'importe où, = risque de bug ou endommagement équippement.

En soit, l'écart n'est pas si grave et j'ai même agrandit. Pour éviter les tensions dans les matériaux.
Lorsque j'ai déserré les vis, Les profils s'écartent, tout seul à cause du bras X qui exerce une pression des roues vers l'extérieur . Bref, ne pas forcer. Mais bien serrer et que tout soit bien d'équerre.

• bras X pas d'équerre, les roues ne touchent pas ensemble chaque butée max. sur Y.

LA coupe du profilé alu était le coupable. Lorsqu'on serre, le plexi se plaque contre la coupe et se déforme un peu. Ce qui crée tension et désalignement.
J'ai ajouté une carte de visite à gauche et ça a rectifié le décalage. YEah.

• le cable managment.
  BAD bad, zero confiance dans l'usage sur le long terme

ça devrait être bien là. Vive la colle chaude.

• tension des courroies, à revoir.
  surtout sur X

Done

• le module laser n'est pas d'équerre, pas droit dans son support
  Attention à ça pour la précision du positionnement. Le module doit être bien callé dans le fond de son support et bien vertical.

• du jeu sur le chariot X
  C'est pas résolu, ça m'énerve, j'vais pas en dormir.
  La solution est d'agrandir les trous de vis pour les roues. Et placer des boulons excentriques. (Eccentric nuts)
  https://www.youtube.com/watch?v=nX0J317l0mY

Ressource tuto assemblage. pour le futur.
https://www.instructables.com/id/How-To-Laser-Cutter/

Et planche de travail pour en dessous.

https://www.thingiverse.com/thing:1678366

côté logiciel,

• la mise à l'échelle des axes. 10mm dans le dessin doivent produire 10mm dans la vrai vie.

• Pulley de 20 tooth

• motor 1.8°

• 16microstep

• courroie GT2

Voir calculateur prusa.

Donc 80 steps/mm à configurer via les commandes $100=80 et $101=80

[nicolasdb]

Reste

• mini bug mais potentiellement dangereux. ⚠️
  Le laser s'allume quelques secondes lorsqu'on connecte laserweb à la machine.

Solution temporaire,

1. Soit allumer la machine = bouton noir ON/OFF, APRÈS avoir fait la connexion logicielle de l'arduino.
2. Soit activer le bouton poussoir sur le module laser.
   Lorsque le module clignote rouge, c'est que le module est en low power pour régler le focus. Et ne sera pas activé lors de la connexion.
   Bouton poussoir blanc en bas à droite, à sa gauche, une led est rouge lorsque le module est sous tension (bouton off), clignote lorsque le mode low power est activé. (bouton on)
   

[nicolasdb]

Bug de moteur qui ne sont pas mis sous tension.
grbl/grbl#589

[Depio]

Ok, Houston, we have a problem.

I order a second minilaser diode for fabmob but I was not please with the first one and I order the same used by bemaker this time. The machine is arrived, it's mounted but the laser module is lost somewhere.
Hopefully, I bought earlier another laser module as safety parts.
and because it's never easy and never work on the first attempt, connectors don't fit.

It's same same as the first (I was thinking)

But with Eleksmaker, it's a 3pin cable for the same module but like this.

The control board is the "SW-LD62 v2"
And I found this part.

Description:
This PWM TO TTL laser module is design for EleksMaker series machine and its controller board.
But it can also be used for other DIY machine which need to change TTL modulation.
Specification:
Power port size: 5.5*2.1mm
Working voltage: DC 12V
Woring power: >2A

Eleksmaker use the mana board controler.

The other is laseraxes board.

Seems less good than the other. And the power supply connector is a bit loose, it doesn't match the size of the power supply (2.5mm vs 2.1mm probably, tssss)
But have 2 place to connect laser, depending of the laser power. both 2pins.
note: I have a second mana board... ^^

So my question is simply, "what about unsolder 2pin connector and solder 3pin connect instead?" Right?

I also got the two lasers (3pin and 4pin - Version).

I want to get it up and running without an external board.
However, I have the problem that I can not disable the laser after connecting to the mains.

I have followed these instructions (https://www.instructables.com/id/Laser-Engraving-on-Your-Prusa-MK3/), but this does not work, nor does the connection of a simple power source and the subsequent removal does not turn off the laser. Only disconnecting the power source switches it off again.

[nicolasdb]

Ok, waw that's quite a hack. @satblip that could be interesting on the prusa :)
Sorry, I saw I continued in french. I'm using issue also to take note during my process then I'm trying to summarize into a clean .md for my github page.

Logically, if the laser is controlled by using the same command as for the fan, using the yellow wire (TTL)
it should work, yes...
but carefull, like they said:

Some printers will have 12V (or even 24V) and you'll need to step that signal down to 5V, otherwise your laser's control module will burn out.

And I actually made this error because I didn't had the right connector and at some point I remember to put red wire on VCC but I changed cable (needed different length) and cables red/yellow was inverted and I put 12V on the TTL 5V. And I burned a capacitor.

Anyway, back to your problem.
I'm actually not sure about the question. Is it to disable the laser when using the printer to print, right?
If you don't want to disconnect the power supply, maybe a switch, because how they connected the laser, it's not possible to not send the same signal to the fan and the laser.
Maybe, 5V is enough to trigger the laser at low power...

[Depio]

Ohh, you missunderstand me. Sorry.

My question:
I bought the 3 pin laser to operate it as described in the manual.

This revealed the following phenomenon:
I connected the laser to the 12V power supply. As soon as I did this, the laser turned on (as described in the description of the laser, this is also normal .. If you do not need the PWM function, you can connect directly to the power port to motor port (12V, GND) on your control board and leave the PWM port unconnected.)

Now I want to use the PWM signal, so I have, as described in the instructions, connected the cable and let the fan rotate. The laser is still fully on. If I deactivate the fan, the laser dims slowly, but then switches back to 100%. It seems to me that the laser processes the PWM signal, but as soon as there is no current at the TTL / PWM pin, the laser automatically switches to 100% (I will probably have to investigate this further)

I also tested to apply 5V to the TTL / PWM pin and then connect the 12V to turn on the laser. This too was unsuccessful. Turning off the 5V left the laser on.

I did the same test with a simple 5V power source. Here, no change in the brightness of the laser was recognizable, since this is just 5V (100% brightness) or 0V (unfortunately, 100% brightness).

After all this was unsuccessful, I ordered a second laser. Now the 4 pin version. Here was a similar phenomenon, which is why I can almost rule out a technical error on the laser almost. But so far I have no approach to finding a solution.

I hope someone can help, because a certain despair spreads at home currently.

At the supplier / dealer, I am unfortunately unaware of, as this itself apparently has no idea regarding the problem.

[nicolasdb]

Mmmm, right.

From what I learned from building, using and repairing the lasersaur, (100W CO2)
The laser tube need power of course but also the TTL part to control the output.
TTL could bet setup as turned ON when +5V or turned ON when 0V (well it's more >3V or <3V)
https://nicolasdb.github.io/post/lasertech1/

Which could explain why on your module, it turn ON when fan OFF because maybe it need a High TTL signal to actually turn OFF the laser....
I'm guessing here.
But, I never tried your setup.
Here, I have tried the conversion from 2p+2p connectors to 3p used with the controller board Mana SE.
and another module, which is without the driver board and it's activated by an analog 12V ON/OFF directly from the controller board (laseraxe)
I never tried to apply power from an external source.

It seems to me that the laser processes the PWM signal, but as soon as there is no current at the TTL / PWM pin, the laser automatically switches to 100% (I will probably have to investigate this further)

Yes, don't forget about the PWM/TLL signal, it should be a constant voltage but with a modulation of frequency. It pulse.
And without any control on this frequency, it could be always interpreted as "power ON at 100%"
or Turned off in a low pulse, which could be low enough to stop the fan but not the laser.
It will not show on a multimeter, You will just see the 5V, for frequency, I think you'll need an oscilloscope to look closely at the signal but try to test with different value of FAN speed.

[satblip]

Really nice hack to keep on the idea board for the future indeed! thx @Depio !