Focus ortur 20v laser

[Kutton (ken utton)]

Can not get laser to focus to dot. All I get is a line.
Any suggestions?

[rtarin (Russell Tarin)]

The 20W is a line and not a dot. Just focus the line to the clearest resolution on a black surface using the laser fire feature starting at about 30mm

[Xeno-Works]

The documentation says, ‘When focused well, the laser spot should be a 0.5mm bar-shape’.

I cannot focus the bar-shape less than 2mm. Which is enormous.
Tried to have the module replaced, tested the new one aaaaaand : same.

I’m at a loss at what to do next. Can’t engrave anything precise with this crap. So disappointed.

[kerrylaw (kerry lawrence)]

Adjust laser up/down, so heatsink of laser is about 55mm from work surface. Focus laser to the smallest “line” you can. It will NOT be a dot.

ALSO SEE …

How do I turn on my diode at low power to focus it or frame a job?

Diode lasers often don’t have a red-dot pointer like CO2 lasers do, so it is often useful to enable them at low power for focusing or framing. (Please do NOT do this if you have a CO2 laser, as the beam is invisible and this could blind you or start a fire) In LightBurn, go to Edit > Device Settings, or click here: [image] Turn on the ‘Enable Laser Fire Button’ switch (make it green): [image] Quit LightBurn and re-run it. You will now have two new controls in the Move window. A …

[Xeno-Works]

Hey Kerrylaw,

Thank you very much indeed for your reply. I do know that the focus ‘point’ is not a point but a tiny bar. I use my googles to focus it as tiny and precise as it will get, but it is still longer than the 0.5mm i’m supposed to get with a nice focus.
I also know that the actual focus dot is not even the bar itself; but the longer the bar is, the less precise the job will be.

Here is an exemple of a test burn done with my 3018Pro CNC with a 15W Laser Module :

And here is the same test done with OLM2 :

As you can see, with the 15W module the burn’s width is equal both on X and Y axis, whereas with the 20W it is wider on the X axis than on the Y axis. There is my problem.

The focus has been done to the best i could, and i actually found that i get better results if the heatsink of the 20W module is approx. 35mm from the surface to burn.
I’ll keep on trying various combinations of module height and focus. I think i’m making progress but it is not so easy

But i won’t give up. This machine is really great; i’ve only got a little focusing problem ^^

[bernd.dk (Bernd)]

“Approx.” Is not good enough , I highly recommend that you do a ramp test in both directions (X, Y). Measure and compare the two results and make your very own distance tool.
Nb. if we assume that 1mm out of focus corresponds to 10% of your power, you lose 0.75W out of the max 7.5W that you have available.