Snapmaker Ray + Lightburn: flame detection

I usually use my Ray on my fully covered outdoor patio to keep the vapors outside.
Unfortunately, when operating under the patio roof, the flame detection constantly triggers. It triggers even in very overcast weather and with the housing closed.
Apparently, the sensor is set so sensitively that the flame detection is triggered even in normal daylight - despite the closed housing.

I then searched the forum and came across some posts about this.

Now I wanted to adjust the sensitivity of the sensor. This can be done in Luban.

My first problem is, which value does what?
There is a range from 0 - 4095 and if you move the mouse pointer over the input field, a help text pops up briefly saying that an input of 4096 switches off the sensor. (If you then do this, some abstruse, very high numerical value is displayed there.)

Does entering a low value now means that the sensor switches on earlier or later?
What is the default value ?
What is the command in Lightburn (GCodes) to make the sensor settings there?

Any help and advice is highly appreciated.

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Same here. Cutting 3mm MDF with one side extra layered which results in semi cut shapes. Thus the need for slowing down the laser, but this causes more flame triggering. In Luban i have set fire sensor to 1 because lower number means lower sensitivity (?). But LightBurn has its own settings for Ray and i ended up with same results. I agree, same setting in Lightburn for sensor sensitivity should be added or at least info on possible gcode editing for this purpose.

I wonder if this has anything to do with the fact that the orifice of the air assist for the 40W version seems smaller than my older 20W laser diode and allows the material to heat up more than necessary…

I haven’t had the alarm for the flame detection. However, I also retrofitted my EcoPlus 200W aquarium pump with 3/8" tubing because the cutting at 80% power at 600mm/min for the 5mm plywood resulted in a much darker burn mark with the stock assist air on. I’ve had another 40W laser diode, and the air assist hole was a bit bigger by default, and I didn’t see the same issue.

I took the fitting that goes on the diode module and cut the plastic push part out, including the inner plastic with the retaining ring. Then, I took the 3/8" tubing that fits over it perfectly and tightened it with a hose clamp. I can take a picture later this week but I have the 3/8" hose with a Y-splitter valve so I can reduce the pressure when engraving but allow the other open port to be opened so I’m not stressing the motor as it gets hot otherwise.

@Jade Hi Jade, are there any statements from Snapmaker on these questions ?

Meanwhile i tried to adapt to the situation and changed cutting parameters. I increased the speed of cutting and set the number of cuts to 2. So it basically takes two passes to cut one shape. It takes more time but it results in half less fire alarms. But it does not eliminate them. I am now cutting plain 3mm MDF which i had no problems with in the beggining, but now somehow it causes this alarm. What bugs me the most is that laser stops working at fire alarm but the machine keeps moving like normal and then at some point starts cutting again. Thus some shapes are left uncut and need to be repeated. Such a waste of time. At least it should have pause function at fire alarm for movement too and then unpause when it is ready to continue. I am thinking about blocking fire sensor somehow (black marker, alu foil tape…), this is now really annoying :rage:

In my case, the alarm doesn’t go away once it has been triggered, even if the laser is switched off completely and then switched back on again (as I said, when I operate the laser outside under my patio roof)

So far the only option has been to switch the sensor off completely (see original post).

I’m not at all happy about this - a functioning flame detection system would be very useful.

OK, i tried to do a job via Luban. The same thing happens after a while…but i get the message and it is actually laser that is overheating, not fire alarm! After every six minutes or so, laser overheats? I clean everything after each job, so it surely is not dust causing it. I get it that this is hobby program but 6 minutes and overheating? Contacting support.

With the 40W laser and lightburn I use for 5mm one sided laminated MDF 100% 750mm/min 2 passes air assist on without any problems. No flame detection.

I use always laser masking tape on both sides.

Support answered and was given instructions for cleaning the fan of laser module. I was not aware that i need to clean the module but it seems it should be done every 20 working hours or every 10 hours if you cut mainly MDF (resin problem), which is all i do. Below are the pictures of the inside of the module when opened, its 100% the reason for overheating.

Enclosure needs stronger fan for extracting fumes for sure. Still glad that there is a solution, i dont really mind cleaning the module.

Thanks Snapmaker support!

Oh wow that’s dirty…I should take a look at mine as much as I haven’t tried cutting any MDF.

Best to rig up a system to feed the head with air from outside the enclosure.

Do you have the new fan?