I’m having trouble lowering my power on my 40w falcon2. 10%, 20%, 30%, all get the same output which is charing through too many layers of the ply. This is at 200mm/s, same thing if I bump it up to 300, no difference.
Why can’t lightburn seem to control the power properly, and how would it be any different to use the button to turn off half the diodes? I’m hesitant to do that because I’d have to split my jobs in two.
That has nothing to do with LB. If your laser has the same output at those stages, it’s the laser head control board that can’t control lower powers well. This is very common, the power is not linearly distributed over the percentage range. Some lasers need a specific percentage to fire at all.
But, with diodes it’s usually quite ok. So you might have a settings issue as well. Are you really using 200mm/s or mm/min? If using mm/s, then 200 will already close to the physical capabilities of the laser. Manufacturers advertise higher speeds, but usually, 100-150 mm/s is the maximum for diode lasers with standard frames and heavy modules. It also depends on the size and type of the project.
That’s fundamentally different. Having half the diodes at full power or all diodes at half power has a very different physical output, the beam shape differs etc. You can’t compare those. Turning off will reduce the spot size mainly, that’s what it’s used for, not for reducing the power.
Thank you very much. That’s correct, essentially max speed, limited by hardware because of short passes / acceleration and deceleration. I was worried it was a non linear type issue… And since LB knows what controller I’m using, I doubt it’s a configuration issue. The gcode being sent should already be telling it to dim, it’s not like it’s modulating the actual current.
And thanks for the explanation on spot sized. I’m wondering now if I’m making my fill pass too narrow, I’ll have to do some tests. Still, if it’s because the power output is non linear, having 2 of the 4 diodes off before I start reducing the power would be a lower total output, but if the beam is more focused, it won’t help much… I’ll have to give it a try to see the difference next.
I never thought I’d end up wanting a 2-10w secondary diode 
but the easy swapping of laser heads would definitely make it a possibility!
But seriously, that’s the kind of details I was looking for confirmation on. At least I won’t be moving forward blindly with my next tests. Thank you for the bad news
I have even multiple lasers above 40W, but for high-detail work I still use the Sculpfun S10 / S30 Pro (10W) which is still unbeaten in terms of power AND precision. Everything above 10W increases the beam size strongly usually.
Could this be a spindle speed setting?
I have the dual power Sculpfun SF-A9.To differentiate between job requirements, I use the Show Notes function to indicate which power (20w or 40w) I should use for the project in the window. For the first time just yesterday, I used the 20w on a project originally designed on the S30 10w machine. Now the Show Notes includes speed/power settings for both machines. Turn on Show on File Open so you don’t forget.
Ok time to roast me. Apparently oak just chars, doesn’t brown. I ran new tests on the red oak and it’s all hideous.
No roast necessary. Different materials behave differently..
Wood can be incredibly tricky, and the settings can vary not only from species to species but from tree to tree, and engraving results can differ from location to location.
The humidity in the air in the shop, and in the wood if it has acclimatized to the shop environment, can also require adjustments to settings.
If all the Oak chars, I’d be inclined to explore the engraving properties of other species of wood with high silica content to see if they behave similarly.
Yeah for now I’ll change back to birch since I’ve got that dialed in.
I’m thinking maybe a LP2 galvo would be worth it for engraving so I can have 1 machine for cutting, one for engraving. Leave each machine to its strengths.
Ahh I think I clued in. That’s dark at the edges. So too fast with no overscan and no ramping is causing stalling and burning on edges as it slows down.
