Defocusing your laser for engraving and etching lines

Defocusing is a technique that broadens the laser beam to create thicker lines and softens engraving. In this video I go over out to do this and what the result look like.
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[@Jacbean10]

This was literally the BEST explanation I’ve heard. Your paintbrush analogy was on point & your tests were great. I’m fairly new to lasering & haven’t stepped into lightburn yet (maybe next year), for now I’m still using the “easy” software my xtool came with. This information was a game changer, I have been struggling with the lines etc. can’t wait to try this technique.

[@angieangie21]

Great info thank you! You could probably use fill and line in Lightburn to neaten and sharpen the engraved edges of the letter "T"

[@DonBonin]

I was thinking the same. Do the fill fast / defocused and then do a more focused line pass to sharpen up the outline.

[@waynes9163]

I just received the new longer nano 6W yesterday, I've been playing with settings, unlike normal set up where the laser is on tracks for its axis travel this thing uses something else as the laser is in static position, I have only done some trials today but have found its useless for cutting, I know a 6w isn't going to do James bond stuff I only want it to cut 3mm stuff but the laser cuts at angular meaning the farther toward the edge the cut is angled not straight through the material as your demo shows but it also even using laserGRBL 20 lines per mm leaves signs of lines when focused properly. coming across your post is great, obviously you're a pro using high end machines not this hobby thing I'm using but I'm going to run some tests defocussing the laser as you describe, thnaks for posting the tip.

[@BeardedBuildsCo]

You’re welcome! Sounds like it is a Galvo based machine.

[@scottm2000]

I tried this technique yesterday on acrylic as trying to create a groove for an O-Ring to sit in using the out of focused line. It works well to give a nice smooth groove, however the cross section of the groove is V shaped which is odd as an out of focused laser shape is the opposite of that. Is there a way to achieve more of a U shaped groove (flat bottom with steep walls) with this technique?

[@kerrycorcoran4885]

Dude, your beard and videos rock! I just got into Laser cutting and was watching this defocusing video. It all makes sense, although I was wondering what is the workflow process to defocus a job. For example, I wanted to create a quick test on acrylic that etches my name, and then I use offset to draw a cut line around the outside of the letters. If I run the job it etches first and then goes to the outside cutline. Do I need to create the same job twice and adjust the floor manually? I assume there is a more effective method. Any insight is appreciated.

[@mikkosutube]

i would guess that adjusting the floor is going to throw the engraving slightly off of the original orientation and it might then not clean up the edges on some of the lines..deepends i guess on the quality of the machine.

[@BeardedBuildsCo]

On my 100w machine I have a motorized bed so I program it to drop when I need it to do this technique. Then it will raise back up for the cut operations.

[@kerrycorcoran4885]

@@BeardedBuildsCo I just ened up running the project in multiple steps.

[@Mageikman]

Awesome video! Are you using plywood for your flags

[@BeardedBuildsCo]

Yes. These ones are 3/4 pine ply.

[@graciescandles8816]

Having problems with lines

[@jakerazmataz852]

Does this work with diode lasers? Can you use this to fill large areas?

[@BeardedBuildsCo]

Yes it is the same concept but you will need to test to draw your own conclusions because the power from the diodes is much less than the laser used in this video.

[@MrBrettStar]

What focal length lens are you using?

[@BeardedBuildsCo]

2”

[@BitSmythe]

No need to say “what’s going on everybody.”

[@BeardedBuildsCo]

Thanks for the comment. I’ll keep saying it though.

[@willthedingo]

I'm just bombarding myself with concepts and information before I get into using my 10W diode laser, then your video showed up in my recommendations. This is SUCH a good idea. I would hazard a guess that a diode laser would require a few percent lower movement speed for every MM raised to compensate for the lower performance as it's defocused, BUT, I feel like it would be a worthy experiment. Maybe a tight in focus outline of the letter to make the edges crisp, and then a defocused "fill" engraving on the centre. Good techniques to consider.

[@ericleewhatever]

Whoa... I had never considered this. Thanks for the video!

[@BeardedBuildsCo]

Sure thing!

[@woodartcncsigns]

what method are you using to defocus? are you using lightburn to set the defocus or manually moving the bed lower with control pad? If using lightburn were do you make this change?

[@2strokeorchoke496]

was this all raster?

[@wilmascrafts5865]

Hi! I'm a newbie here and just subscribed to your channel. After you defocus, what setting do you adjust to sharpen the edges and deepen the cut? I have a 70W laser. Thanks!

[@BeardedBuildsCo]

You can adjust the line interval/lines per inch. Getting deeper you increase your power and or decrease your speed.

[@mrmorden76]

Thank you that was very helpful 😊

[@BeardedBuildsCo]

You’re welcome!

[@SarbarMultimedia]

There is no criticism of the principle you are trying to demonstrate. Dropping the focus will do two things for organic materials. First it reduces the CUTTING ability of the lens as the line widens and secondly it reduces beam INTENSITY so that the wood scorches. more and more as you defocus. Usually 6 to 8mm is optimal. A fascinating illusion happens when the beam is correctly focussed and CUTTING deep thin black lines. In reality those lines are not burnt black. If you section a cut, the face of the cut is virtually scorch-free The black illusion is created by occlusion of light not getting into the cut. . Only when you reduce the CUTTING ability of the lens by defocus does the cut depth decrease and the instant material vaporisation become scorching