Z control between layers

Hey guys this auto z bed is new to me so I havent used it to its fullest. Wondering if I am able to have a layer scan then move the bed closer or further away to a height that I choose and then proceed to scan or cut per next layer settings.
For example I have a 15" pine round that i cut on my cnc so it has 3 concentric levels, each a little deeper than the previous. I’d like to engrave or vector engrave a design on each spot and have it be in focus.
Another would be to run a job that’s way out of focus so it has thick lines when I vector engrave, then come up in focus and do the cut
Also taking a cut and then before the second pass it would raise the bed and then cut.

Anyone have some input on this?

You can, but LightBurn onlyi allows one material thickness per job, so the other layers would need to use the Z offset to get them to the correct heights. I’d recommend using the thickest part as the base material height, and using inward offset to push the head down for the inner parts, to make sure the head doesn’t crash into the object you’re engraving.

You would also need to enable Z moves, and you probably want relative Z moves on, as that’s simpler - you just manual focus on the material, then start the job, and the software reads the current height and runs everything relative to that. Both of these options are in the Device Settings.

And yes, you can run a line out of focus, or use the Z step per pass to push into a thick material - mostly useful for diode lasers, but might be worthwhile for CO2 systems too.

Are there any videos on this? So I could start out with the focus say 1 inch higher out of focus so I enter that in z offset and say 1 pass with .5 inch z step per pass then after it does this layer (vector engrave) then raises up and next layer. Then I could do the same thing but as a different color then raise .5 and then I’m at the focal length to do a cut?

There are no videos on this - my own machine doesn’t have a stepper-controlled Z axis.

I couldn’t follow what you wrote, but the Z-Offset value in the cut setting specifies the height of cuts for that layer, relative to the overall height of the job. If you have 3 layers, you could have the first layer set with an offset of 0 (use the normal focused height), the next layer could move down 1/2", and the layer after that could move down 1".

All Z moves are zeroed out after the layer runs, so each layer sets its own height relative to the global material height, not relative to the last layer that ran.

yea thats kind of what im saying.

  1. i have a job where i want to engrave 3 layers with the same settings except they are all .2 inches height difference. so i would get the top layer to engrave with 0 as the z offset. then next color i use same settings but have a z offset of .2? then can do another color with same settings and have the third color z offset also .2 and then it would engrave them all at the same correct?

  2. i would vector engrave out of focus, say 1 inch. so i just do the engrave with 0 offset and then the next color i cut with i would set the z offset as 1 inch so it would raise the bed and cut in focus.

  3. just playing around cutting thicker material and if i want to do a 2 passes but i want it to raise up between i could tell it 2 passes and .1 per pass. then it would do a pass and then raise .1 and begin the last pass

did i understand this correctly? thanks sorry if its confusing hope this is clearer

  1. If you had three layers, all 0.2" apart, the settings for the three layers would be 0.0", 0.2", and 0.4".

  2. Correct

  3. Correct, though the more common way to do this is to have the focus move into the wood with each pass. Say you cut halfway through with the first pass, then you focus on the point 1/2 way through the wood to cut the other half. It doesn’t work well with short-throw lenses, but diode systems benefit from this because they’re weak and have long-throw lenses.

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