Hi Folks I've just got the laser on my CNC up and running,

Hi Folks

I’ve just got the laser on my CNC up and running, and I made an engrave test pattern, where I get some markings in areas where I don’t expect them, they are especially visible at the 10% and 20% power.
I think it’s a delay from when the laser starts and the cnc starts to move, but I’m not entirely sure.

Can this be fixed in with some setting in Laserweb?

You need to enable a feature that is often referred to as overscan. At most speeds, 3mm is enough. It makes the head travel further and the ends of the pass when changing direction.

Please enable overscan and make another picture and post.

Thanks for your replies - overscan makes sense.
But I can only see it in raster mode, and all the squares are made in “Laser fill path”, and I don’t see overscan in that mode.
Does the “Margin” setting do the same?

Been a while since I used Laserweb. I thought it was available in all fill and raster modes. I could be wrong though.

@Kelly_Burns I don’t think it is.
I’m using 4.0.996 and the options for Laser Fill Path are:
Filter Fill
Filter Stroke
Line Distance
Line Angle
Laser Power
Pass Depth
Start Height
Cut Rate

hopefully someone else can chime in. I rarely used Laser Fill mode. The result on your engraving seems a bit excessive.

I just realized that this is a Laser Mounted on CNC. I’m assuming its a Diode Laser. I don’t have a lot of experience with DIODE Lasers. Perhaps the Shutdown of laser is a bit slow compared to CO2 laser. You may need to tweak some settings with regards firing of laser and acceleration. It’s possible this may just be a side effect you have to live with or only use Raster Modes.

What controller and Firmware and Laser are you using?

I’m thinking you are having issues with Firmware that is not optimized for Laser or you don’t have LW configured to use it correctly.

That’s right - It’s a 6W diode laser.
So it might be something to do with the control of that.
But I don’t think it’s a stopping delay, since the line is on both sides.

Although… Now that I think about it it might have been firing in both directions.

@Jonas_Hermansen which laser diode are you using for this?

i seem have the same problem. i have a 15W diode laser and i have a problem setting the power value. using 5% of power the laser doesn’t engrave anything. i have to use high level of power to engrave something, and cutting fibre panel of 3mm requires 5/6 passes at 100 mm/min and 100% power. do you have some suggestion?

@Matteo_zappa “i have a 15W diode laser” no you don’t. The most powerful laser diode in the world is the Nichia NUBM44 - 6.0W. You can push it higher, but at the cost of dramatically-reduced diode life.

“i have to use high level of power to engrave something, and cutting fibre panel of 3mm requires 5/6 passes at 100 mm/min and 100% power. do you have some suggestion?”

That’s worse performance than my NUBM06 at 4.5W. I suspect your Chinese diode and driver are not what they claim.

Three things affect a diode laser - power supply, cooling, diode. As you are stuck with the diode you have, I would improve cooling (add another high cfm fan) and buy a better controller (like an x-wossee 5.5A unit).

@Mike_Thornbury grazie tante. Avevo già sospetti che non fosse quello che avevo comprato. loro dicevano 15.000 mW e che poteva incidere alluminio.

ho notato anche un problema col taglio: quando taglio lettere su carta, le linee curve non si congiungono, e quindi la lettera non si stacca a dovere. è un problema di impostazione del software? con le linee rette non succede.

grazie per le informazioni. in futuro sto valutando di sostituire la testa con una a co2 oppure altro. ancora non so

Don’t give up on this one. It’s not 15w, but lots of people do some cool things with these diode lasers.

I believe most of your issues are caused Firmware configuration.

@Matteo_zappa They are ‘pulsing’ the laser to boost the power, but at the expense of continuous lines, they instead have a series of dots. it is possible to make it deliver continuous power, but you will need to change the driver for a better quality one.

As @Kelly_Burns says, don’t give up.

You will never cut aluminium with a diode laser - it’s extremely hard to cut with a 150W CO2 laser. But, you can mar/etchk anodised aluminium and should be able to cut 3mm mdf, acrylic, plywood in a single pass with a ‘15W’ laser (probably a Nuchia NUBM08).

For my needs, a diode is perfect - cutting light plastic sheet, paper, cardboard, cloth, and for etching in wood.

If I sell enough of them I will buy myself a 100W CO2 :slight_smile: