Rambo 1.4a + Laser

Hello all!

  1. I need help to connect the laser to my lowrider on the rambo 1.4a board (https://www.aliexpress.com/item/32958037528.html?spm=a2g0s.9042311.0.0.27424c4dO6m4K7). I found several topics about lasers and a howto on the site, but all this concerns old rambo boards and lasers with a separate control board that only need 12V power. Maybe I do not understand something, but is there a clear instruction for connecting the laser pwm to the rambo 1.4a board? I will add a photo of my laser and my board.
  2. For not to multiply topics: I have almost finished the work necessary for the airbrush module for my lowrider. For this job, I need to connect a servo machine to control the opening of the air supply valve. I found articles about connecting servo to the old version of rambo (https://3dprintboard.com/showthread.php?9335-Rambo-Servo-Setup-for-Auto-Bed-Leveling-for-Noobs) but in my version these contacts are located otherwise. I do not want to burn something, someone will help with this issue as well?

See if these clear it up for you.




I have never used a servo on theses boards but you can have a look at the firmware and pinouts to get that working, both need to be edited for a servo.

I understood my laser 12v - this means I have to connect it to the 12v fan pins. Does this mean that I only use 2 wires + and -? I thought that the control is carried out through 3 wire PWM …

Direct me, in what config is the pin matching on the board, where I can read about configuring the pins on the board, I have not come across this before that time.

Thanks Ryan!

That is the problem with lasers. I have no idea how yours needs to be wired, they are all different, some are even labeled wrong. If you didn’t buy the recommend laser from the article, you either have to hope someone else that bought the same one steps in and helps or guess and check.

It seems I myself answer my question - this is a file pins_RAMBO.h

In the very first lines I see Servo:

// // Servos // #define SERVO0_PIN 22 // Motor header MX1 #define SERVO1_PIN 23 // Motor header MX2 #define SERVO2_PIN 24 // Motor header MX3 #define SERVO3_PIN 5 // PWM header pin 5
Ok. I see "+" and "-" in MX1-2-3 pins , but pin 5 PWM ? Which of the remaining 3 in the row is PIN 5? Leftmost on the other side of the "+"?

I correctly understand that I can have 3 servos on the MX1 MX2 MX3? Which team should apply to control the servo I need - MX[N]?


ok, i found: M280 P<index> S<pos>

The question remains on the PIN, where in the MX [N] PWM pin?

Motor pinout is lower right corner.

Damnit, can’t zoom…


1 Like

Anton did you figure out how to plug it i would like to install a laser to my cnc machine also on a rambo 1.4 ?


Hello. Yes, I figured it out and connected. In general, as I understand it, the connection of all similar lasers is identical, the main thing is to be sure of the polarity. I will take a photo for you when I arrive at the my workshop, as well as the marlin code for pins.


Anton thanks a lot it will help me so mutch
when i will have all my parts i will probably to contact you again lol