Laser cutter from 3D printer wiring issue

Hi there;

I am trying to convert a 3D printer to laser cutter.

I got this laser module bought from Aliexpress:

[es.aliexpress.com]

I am trying to convert a TEVO TARANTULA 3D printer.

The motherboard is MKS Base v1.2:

[gr33nonline.files.wordpress.com]

I tried to connect the wires to fan plug in the motherboard and the power supply and the laser turns on, but I can't turn it off using Gcode codes (M106/M107). This codes are enabled in firmware (I tested it using a simple fan, and it works) so i guess the problem is with the laser module connections.

This is my connection scheme on attached image

Would you help me to solve the problem?

Best regards.

Álvaro

Edited 2 time(s). Last edit at 07/27/2020 05:21AM by Gorebar.

You cant connect -ve line to power supply -ve

the mosfet switches the -ve line. when you have it wired to the supply -ve it is always on.

I would also expect ttl to be 5v not 12v...

Edited 1 time(s). Last edit at 07/27/2020 06:00AM by Dust.

I would try 12v - and + directly to the laser module 12v pins
the 3rd pin I would connect to a pwm capable line eg D11 or D12 on the servo pins and in your firmware set FAN_PIN 11 so you can control it with m106.

but im quite worried you have destroyed the ttl pin with 12v

Edited 1 time(s). Last edit at 07/27/2020 06:12AM by Dust.

Hi Dust!

So... to keep safe (anything LOL).

I am a really noob with that, this is my new scheme (attached file). Thats right?

PS: The TTL pin looks good btw hahah

Thanks

... check the +/- pins on your laser module!!

---

Viktor
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Yeah VDX, I checked and looks correct. But I am not sure what is my problem.

I going to change what Dust told me about pin D11.

I'll write again with news.

Thanks!

the board seems to indicate that gnd is first pin, +12v is second pin, ttl is 3rd pin.

In your diagram you have first pin as 12v second pin as gnd and third pin as ttl.

You are right. My fault drawing the diagram. But its correct in real life LOL.

I'll test then!

Thanks!

Well... Thanks for your support! It's working good right now.

Thank you for the wiring diagrams Gorebar, This is what I have been missing. I have a laser module that is PWM but other than that it has the same labeled pinout on the laser board:
12 G P
V N W
+ D M

and was not sure how to wire it to the RAMPS 1.4

I will be putting the 12V+ to D9+ the GND to D9- and PWM to D6+

Someone please stop me if I have this wrong, I have already burned an Arduino from miswiring and melted 4 ft of wire trying to figure it out. Your images have really helped.
I will ley you know if I got it all working once the new Arduino comes in.