I don’t know what happened but my diode laser is not cut wood material. I watched this YouTube video that showed by setting the S-value to 10,000 in device settings, and in machine setting the Max spindle speed, S- value to 10,000. The video showed cutting through the material. I did that and still downtown work. What else in settings am I missing to set. Appreciate any help. Thanks!
Hi Mejia,
If you’re working with your ACMER laser, can you confirm that the wood is properly in focus? ACMER has a focus stick built into the heads of their diodes for most machines:
We have a video covering typical low-power problems here:
Colin, thanks for the info, I will check the focus stick and will clean laser lens. I’ll let you know how I come out. Thanks.
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Normally S value on diode is lasers is S = 1000
Hey Loren, thanks for your help, I changed the S- value still didn’t cut through the 1/4” plywood. I perhaps need to invest in an other laser. Thanks again.
Colin, checked focus stick and cleaned out laser with alcohol. No luck. Thanks for reaching out.
The S-Value max setting it 1/2 of the settings. This tells Lightburn the maximum spindle setting value, but ignores the fact the controller also has to know this to work correctly.
If the $30 value for the controller isn’t the same as S-Value max then it’s going to be a problem.
There was no mention of laser power (5w, 10w, ???)
No mention of speed, %power settings, or number of passes either. And does it have air assist?
That 1/4" is going to need extra attention to all the things you can adjust. Without the information mentioned here, we cannot tell if it is a performance or settings issue.
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New at this so not sure what details to provide that will make easy to troubleshoot. I’m using an ACMER 20W laser. The first projects, I used 400 speed and 80 power and it cut all the way through. And I’m using air assist. Thanks.
I don’t know if this is standard setting for all lasers, I watched a video where the individual set his max spindle speed, s- value to 10,000 in machine settings 10,000 s-value in device settings and it cut through his material. Traded those same setting using my ACMER 20 W laser and didn’t cut through my 1/4” material.
The software generates the codes to tell the controller what pwm it generates based on a known constant. These controllers will generate the proper control over a laser and a machine with a spindle.
These known constants are the S-Value max (spindle maximum speed) and Spindle Minimum values. In Lightburn the 50% point between 0 and 10000 is 5000, for a 0 to 1000 value it generates 500. First would generate an S5000 code, the other an S500 code. Unless you know what it’s based on, how could you control it?
As far as I know, lasers assume minimum spindle speed is zero.
Both ends need to know what minimum/maximum spindle speeds are.
It’s not really complicated. 8 bit machines usually use 255 (or 254). If you have a machine that’s 32 bits, then they produce more precise values with larger numbers.
Lessons learned:
- What you see on YouTube rarely works for your specific situation.
- If it ain’t broke, don’t fix it. With Svalue=1000, it cut through the 1/4" material, right?
Reporting your settings (yours is diode):
- Cut speed in mm/m (millimeters/minute).
- Maximum output power (typical 5, 10, 20, 40, 70, sometimes in between these).
- Percentage of output power in % (percent).
- Number of passes.
- Air Assist, yes/no.
- Type of material.
- Thickness of material.
- Type of controller (GRBL, Ruida, Marlin, DSP, etc.) helps.
- Type of laser (Diode, CO2, Galvo, Fiber, RF, etc.) helps too.
Your response:
- 400mm/m
- 20w laser
- 80% power
- 1 pass
- Air assist
- Home Depot utility plywood
- 1/4" (or 6.5mm)
- GRBL controller, v1.1h
- Diode
This tells us an amazing amount of information we can compare to our own experiences. In other words, we should be able to approximately duplicate your results with a machine of our own. 
I believe the s should equal 1000 inLB
I’ve set the s-value’s in device and machine settings to 1000 still not cutting.
Give us some detail to work with, please.
- I’m using an ACMER 20W diode laser
- I was able to cut through 1/2” standard plywood and now not even 1/4”
- settings I used were 400 speed and 80 power
- Using an ACMER 10W 25L/ min air assist
- Have done good with 1 pass
- Using GRBL Controller
- Last thing I did before firguring out I couldn cut through material, was I removed Diode laser to clean soot of lens.
Is this saying it was ok until you cleaned the lens?
That is a pretty important detail. It is pretty easy to reassemble it wrong or insert the lens backwards.
I cleaned around the laser housing and used a q-tip to remove soot from the laser hole. There was no disassembly of any parts.
Ok, that was not it, but…
You did not clean the lens. That was the exit hole of the nozzle. You have to remove the nozzle to get to the lenses.
There is a curved lens, and below is a flat lens to keep gunk away from the curved lens. Normally, it is only the protective lens that gets a cleaning.
If you did not use air assist during engraving, but did for cutting, you can still gunk up that bottom lens. Was the air off during engraving?
There are a bunch of YouTubes on how to disassemble it and clean the protective lens.
I use the air assist for both cutting and engraving. I will research on how to clean the protective lens. Mike, I appreciate you spending your valuable time to help me. I should be able to figure it out with comments from all the folks that chimed in. Thanks and take care.