Description covers it - 2500mm/m, 25%, 9 passes in 3.5mm walnut.
Falcon2 Pro 40W Diode
Curious what setting could help this? Seems like the laser is lowering power as it gets ready to make the turn? This is the back view and the laser traveled clockwise from this view. Something changed as I was able to do this cutting last year during the holidays. Now it’s making the cut but not those last bits. Did something change with Lightburn GRBL?
Acceleration is set to 1000mm/sec ^2 for both x and y. Default machine settings.
I see mention that this is to avoid burning the corners however it seems this is too aggressive. Is there a ‘knob’ to turn to adjust this?
Doubling my power to 50% and doubling my speed to 6000mm/min shortens the uncut bit but it feels like some math with how lightburn or GRBL adjusts power with corners needs a knob for us to turn?
Thanks - already checked my settings against that document. Nothing for me to try there.
Higher speeds helped minimize lower speeds in the corner it seems and less ramping down of power.
The outline cuts fine(longer lines than inside) with last years settings minus a little bit at the end with deceleration. The inner pieces are worse. Last year I crept up on the cutting setting as I wanted to use minimal power to minimize burning of the edges.
Did anything change with how lightburn ramps down power into corners?
No, because LightBurn just sets the overall layer speed.
The controller regulates the laser head speed using the axis acceleration / speed limits, with more-or-less proportional power adjustments as the speed changes near the corners.
If (last year) you set the LightBurn power just high enough to not char the edges and the laser diode has weakend with age, then (this year) the results will be about what you see.
It’s also possible one or more of the laser diodes has completely failed, so that what was once 40 W is now 35 / 30 / whatever. A “wall test” at various power levels whatever may be revealing:
I ran the same SVG with settings the same in Falcon Design Studio as in LB, 3000 / 25% 9 passes and you can see, Falcon Design Studio on the left did a better job of getting that last little bit before turning the corner(smaller uncut section).
Wall test presents a clear pattern, no gaps. Thanks for pointing this out.
Edit - I only went up to 4%. I have the pro which needs the red enclosure closed to fire so I pointed it at the back at a piece of angled cardboard at the back of the enclosure which puts it around 20” away. Also wore the green safety glasses that come with it. I read that different LEDs fire to support different power levels. Not sure it’s safe for me to do this to fire it up to 100% to fire all possible LEDs without the right safety setup.
If the laser has switchable maximum power levels (20 W, 40 W), then that selection controls the number of active diodes. The LightBurn layer power then adjusts the output power of the active diodes from zero up to the switch-set maximum power.
So I think you’d see the same number of diode stripes for any LightBurn power level, but different numbers for each maximum power level.
IIRC, each laser diode has something like 5 W optical output, so a 40 W (optical output!) head should have eight active diodes producing eight defocused stripes.
There are a myriad settings affecting the outcome.
Tracking down what’s different involves speed, power, that pesky Max S-Value setting, and so forth and so on, but you should be able to get equivalent results after you identify all the differences.
I had one copy of Lighburn configured for GRBL-LPC which is not connected to my laser which I do my heavy design work.
My other two installs of Lightburn are set to GRBL. Including the one that is connected to my laser via USB which auto detected it(Creality Falcon2 Pro 40W) as GRBL.
Bumping this for my update two posts up. In Machine Settings, if you’re set for GRBL, the constant power mode switch is available while if you’re set for GRBL-LPC it’s not. See pics above.
Yes, because the availability is dependent on the firmware. It needs to understand the command. It’s not a LightBurn feature, it’s a thing a laser is capable of or not. As always, you need to make sure to use the correct settings. Grbl-m3 type also does not provide this.
