From a noob: Snapmaker Luban Pass Dept (laser)

Hi Guys,
sorry in advance for my - maybe - stupid question. I’m a novice in laser cutting ( I received my SM2 one week ago).

What’s exactly the meaning of the pass depth parameter? From my understanding, in a multi pass process, it is the distance the laser module is lowered towards the material surface after each round. But, being this correct, it means it must be considered the total distance of the laser module from the material surface because if the pass dept multiplied for the number of passes is grater than the total distance of the laser module the module would hit the material.

Is this correct? Thanks for your support!

You’re right! The laser has a lens hood screwed to it, you could remove that to get extra depth if you think you need it.

Thanks for your reply!
I’ll check how to remove the lens hood.

The lens hood is made so you can adjust it to better shield you from the laser. You should lower it as much as you can. That works great for laser engraving but not for cutting multiple passes. In that case you have to leave enough room for travel and if necessary can remove it completely.


Thanks for your follow-up!

I can understand that the lens hood may need to be removed into order to accomodate thicker materials, but I do not understand why the machine would try to push the toolhead beyond (lower than) the total thickness of the object.
That is: If I specify that the material is 2mm thick, then why would the machine let me lower the tool head past 2mm in a multipass situation (such as 5 pass at 0.5mm/pass)?


I haven’t found a need to take off lens hood. So far I’m not sure why one would need to.
My focus distance is ~25mm. Which generally with the length of the barrel and the hood means that I have the barrel unscrewed about 3mm to put the edge of the lens hood 1-2 mm off the piece. For single pass I make it tighter. For multiple passes I raise it up accordingly and err on side of clearing piece vs. blocking laser since I have enclosure with amber acrylic.

Just found out a reason to remove lens hood.
I had some glass tile that had a silvery surface on the back side.
I tried engraving the back, and while it looks good with light from behind it, from the front it wasn’t any better than engraving the top surface.
But by removing the lens hood I was able to focus through the glass.
Could reduce the power a little because the surface bubbled a bit in a couple places but results were pretty impressive as is.