How to "jog" the z axis to fine tune laser focus

So, I’m moving from CNC routing to tinkering with a lower end of the line laser I got from SainSmart to use on a small 3018 Genmitsu. I decided to use lightburn because it feels like some of the other design programs I use, and I was able to create a nice logo quickly. Here’s the problem, I can’t figure out how to get the laser to raise (like jogging up a router bit in small increments) so I can quickly adjust for getting a good line. No, my laser does not seem to cut lines and fills equally well at the same power/speed settings. I feel like I could solve some of this by just being able to adjust the z axis a few steps (.1mm) at a time, until I got a good burn. I can’t find how to adjust that. As it is, if I click on the down button in the “Move” window, the laser lowers about a centimeter at a time. The “Get Position” shows Z at 4.13, but I don’t know what that’s really used for. Is there a tutorial that specifically explains how the z axis comes into play in laser burning or how to at least set it to manually jog it small increments at a time?

The ‘Distance’ value in the Move window controls how much it moves with each click, but it’s not usually necessary. The focus of the laser is adjusted by turning the focus ring at the bottom of the laser housing.

You can enable the beam at low power for focusing. (Instructions here: How do I turn on my diode at low power to focus it or frame a job?

If you are trying to cut material, sometimes you can make more than one pass and step the Z down a little with each pass to help get through, and sometimes pushing the Z up or down during a job to un-focus the beam can be used to make a thicker line, but that’s harder with diodes - they’re pretty sensitive to good focus.

In order to use the Z during a job, you’ll also need to go to Edit > Device Settings and turn on ‘Enable Z’, and for simplicity, turn on ‘Relative Z moves only’ as well.

Thanks! That was very helpful. Now another question. I have the laser focused tightly on the surface of my material (wood). I find that running at 200 mm/min at 20% gives me a nice line that isn’t too burned around the edges, however when the laser is doing a series of outlines in a row (like unfilled boxes), it does a box but as it moves to the next box, it does not turn off the laser over the dividing area and leaves a burn line at the crossing point. Is there a way to fix that?

Welcome and glad you are making progress. Using the forum search :wink: , I found this:

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.