Laser cutting plywood

Hi! I really hope someone can help me! I have tried for months to cut through plywood with the 1600 laser but no luck. Well actually I did make it once but it took one hour to cut a 15mm dia circle :joy: I have seen so many of you complete laser cutting after laser cutting and I have tried all your advice but still I have no chance getting through. I am no expert using laser, I usually use it to engrave buttons but I really would like to cut through plywood so I can make other things :slight_smile: pls help me!! :slight_smile: oh and yes, since I still haven’t recieved sm2 I use the sm1 and I have tried in snapmakerjs and luban:)

@Nina I can may help you.
I tryed cutting beech and poplar plywood. I did a lot of tests. What kind of worked for me with poplar was at 4mm tickness: 100% 350mm/min, 2x 11x -0,35mm in Z, starting at the exact work piece hight of 4mm.
For beech it was the same but with 3x 11x -0,35mm in Z.
Less pathes with slower speed could work but in my opinion the side surfaces suffer to much if the work speed is to low.

What you also can try with poplar is: 100% 400mm/min, 2x 6x -0,6mm in Z, starting at work piece hight.

From what I see you should buy material that is <= 3mm otherwise it takes forever to laser stuff an the last 1/10mm are not well cutted. If the material is thicker the laser can’t focuses all it’s power in the deep cuts. I think the first 3-4 cuts can go to a depth of like 2-3mm. After that to less focused energy reaches the last 1mm and it takes several pathes to cut trough this even with the adjusted depth.

At the moment I try to laser a sunglasses holder. I did a lot of tests for that. I will pass as much information on my website as possible. You can find the link in my profile.

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Hey Scorch, I’m a total nube so can I ask for a “Geez, you are dumb as a plank” type explanation for what ‘4mm tickness: 100% 350mm/min, 2x 11x -0,35mm in Z’ means? Those of us among the uninitiated thank you :slight_smile:

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@kevfree
Hi I try to explane the values.

4mm tickness => It’s the thickness of the material that was laserd
100% => refere to the power of the laser. So you use 100% of the power of the laser. You can set the power in Luban on the left side. Attention: If you change the power the laser will turn on and off for a short period of time!

350mm/min => that’s the speed the laser will mover over the work piece. Not to fast or the laser has no time to evaporate stuff and not to slow or you may start a fire! I prefer a little bit faster to get a little bit better edges.
You can set the speed in the Luban Editor on the right side. If you run tests be sure the speed has transferred correctly to the g-code. I wasted some time doing multiple tests with the same speed.

2x 11x -0,35mm in Z => You can let the laser cut the same path multiple times. In addition you also can lower the laser after each rund a defind dicance. In this case after each rund the laser will lower 0,35mm in the Z-axis. You do that to have the focus on the point were material is left and not in the air. If the laser is out of focus it loses power to evaporate material. In this case let the laser make 11 rund. Because the laser can’t be lowered endlessly I start a second time from the top again. That is the “2x” because I let run the Z lowering process two times.
You find this settings also in the Luban Editor on the right side under the mm/min slot.

And don’t forget to do the laser auto focus. You also can start it manually in the SM screen by swiping to the left. This is not so obvious unfortunately.

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Thanks for this explanation. How do you do the multipath twice? The processing options let you set a run of 11x at .35mm drop each run, but where do you tell it to do this 2x?

I just start it again. :smiley: :wink:

I hope this isn’t long enough after posting to count as necroing the thread <_< I’m just trying to wrap my head around these laser settings, and it doesn’t quite make sense to me that running the job twice would actually result in a deeper cut… wouldn’t the laser just be cutting in midair for most of the second run? I mean, obviously it works, from your results! But do you know HOW it actually does anything? I am very confused, haha

It’s not like a saw blade or a router bit that has a fixed cut distance.
While there is a fixed point of focus where the beam is at it’s smallest and most concentrated, and powerful, it will still have an effect (with diminishing results) along the beam in both directions.
When you run multiple passes you’re usually running the consecutive passes at a lower level. So you’re lowering the spot where the most effective cutting is happening as material is removed. Even if you don’t lower the laser, it will still usually cut through just not as effectively. The key is if you can figure out how much material it’s removing with each pass and lower the laser an equivalent amount each pass.

Hope that makes sense?

-S

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Gotcha! Thanks so much for the reply. I guess the point I was missing is that it’s not just binary “laser focused = cut” versus “laser unfocused = do nothing”. Even if the bottom, say, 0.2mm of the material aren’t focused enough for the laser to cut through in one try, it still does enough that hitting it again from the same distance CAN help. But yeah, it seems like moving down by however much you managed to cut is most efficient!

Just sharing some information I’ve found, that has made a difference. I don’t know why it took me so long to realise wood is inconstant, first thing I was taught in woodwork it to dress the wood, never assume it’s straight ect. ect.
Anyways, reading through Snapmakers Engraving and Cutting Manual and found this


I was loosing my mind as to why sometimes I had found the right settings and it would cut, then it would all of a sudden stop cutting and would be scorched… When checking my wood sure enough, I had some 2.5mm wood that was 2.8 and 1.5mm that was 2.1mm! This knowledge has made my cuts a lot more constant being able to compensate for the wood thickness. It’s also brought to my attention that if the wood is sitting up a little bit a 0.2mm height difference is enough to not finish a cut.

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