I bought at the beginning of August a small laser cutting machine type k40.
And for lack of time, I just plugged it in.
The driver and software installation went well …
I start to do the first tests and nothing happens …
I open the beast and do other tests and there I realize that the laser remains 3 cm from the exit of the tube by attaching itself to a small metal part …
I’m really new to this area but really don’t understand the problem …
What you are seeing is not the laser. That’s the plasma that “excites” the laser. The laser beam is invisible. It is very long wavelength infrared, about ten times as long a wavelength than the deepest red you can see. That’s why you see it attaching itself to the metal conducting ring. The invisible laser beam can’t bend like that and exits the tube.
First, before asking other questions: Are you running water through the tube to cool it?
Second, have you read the K40 Intro linked from the top of every page here? It may save your life, your home, and your laser. That page, as well as each of the brief articles it links to in the Getting Started category, are intended to be the “missing manual” for operating a K40. There is a great deal of useful information there that might help you.
As @mcdanlj points out the laser itself is invisible. The fact you do not seem to know this concerns me for your safety.
The laser in this machine:
*** It is powerful enough to blind you without you seeing it**
*** The power going to the laser can electrocute you.**
You must wear eye protection and keep the covers closed when the laser is on and you are working with this machine.
After you read the material that @mcdanlj suggested return here and we can help you get the machine working.