K40 with M2Nano with a lot of problem to solve


I’ve bought a K40 running on a M2Nano with a digital panel but ever since it has arrived nothing seems to work.
Y-Axis moves to the wrong direction when I switch on the machine till crushing against the metal enclosure and the M2Nano doesn’t connect to my laptop (MacBookPro).
I attach a video of what happens…
Video 1

I was wondering if buying the Cohesion3D laser board I would solve all these issues at once.
Can I simply swap the two boards re-connecting the pins I already have? My laser has optical limit switch, would that be a problem?

I attach a picture of the current set-up.

Also, I’d like to move from a digital amper reading to an analog one, any advice on what should I buy?

Thank you very much for your support!

I mean, the motors are moving, that’s a good sign.

If your stock setup has issues, I can’t say that it will be a drop in replacement and be up and running in 20 minutes as advertised.

All we care about is driving 2 motors, reading 2 sensors for homing, and firing the laser.

Maybe your Y motor are wired up backwards (although I have never seen this before) or maybe you have a bad sensor for Y. Worth doing some investigating. I can’t tell any more from your video, I watched it several times.

Less likely but still maybe you will have to rewire some things.
I would recommend getting 2 of these switches just in case you do need to replace the homing sensors:

The LaserBoard will make it easier to debug all these things for sure.

We have a good potentiometer listed on the site and I also have a nice head for it and mA meters here, I just need to list them on the website. I will try to do that later tonight.

In the meantime you can read the Buyer’s Guide to determine what other items you may need:


I managed to solve all the issue and now the laser is properly working.
Still, I’d like to buy the Cohesion 3D laser Board.
Could you please list the head and mA meters?

Also, do you have wiring guide for connecting all the pieces together?

Many thanks,

My very best,


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