Since upgrading to the latest LW3 a couple weeks back, I keep getting grainy engravings on stuff that I’m doing sort of deep engraves with. I’ve played with beam diameter, and I’ve double and triple checked that my vectors are being exported as 300dpi bitmaps. This is done on birch ply, modded K40, with Azteeg X5, running the latest CNC firmware. The completed one was done 300/175, 7mA, the other was done 300/175 at 5mA. Beam diameter is .075 (had been .1) The homer looks pretty good. But none of it is really very deep.
Could it be related to beam focus? Is your material sitting at the same height compared to prior to updating to the newest version of LW?
@Yuusuf_Sallahuddin_Y it is. I cut a little jig that I use to adjust my laser head to the surface of the material.
@K1111 You could try slightly defocusing the beam, as that usually produces softer results for engraves.
I’ll give that a try as well. I moved back to .1 beam diameter (I had been trying .075 to see if it helped), and I get the same issue, just not as pronounced. The odd thing is that in all three photos it looks like a sort of leaning pattern.
In that last photo I reminds me of denim.
@Yuusuf_Sallahuddin_Y Question about defocusing… I generally work with 3mm birch ply, and I set the beam to the middle of the wood for best cutting. Should I refocus to the top of the wood, but slightly closer or farther?
+Peter van der Walt I actually turned that on with the last photo I took. Maybe that’s why the last photo looks better and not the beam diameter? I also noticed it seemed faster than when it was off.
@K1111 With defocusing for engraving, I tend to usually focus at the top of the material.
On another note, there was talk a while back regarding “moire” patterns caused by the frequency of the power or something? I can’t remember exactly what about it… but there was discussion on it in the K40 community.
This doesn’t seem to be the issue here (visually your result looks different), but just had a thought it could somehow be related.
@Yuusuf_Sallahuddin_Y actually that’s interesting, because my first thought was that it looked kind of like moire.
Slanted? If you cut all the way through, is the cut slanted? If so, your laser may not be perpendicular to your material surface. I had that problem with my CNC mill’s cutting bit. I imagine it happens with lasers too.
Yes, I am discussing a side topic.
@NathanielStenzel The cut is not slanted.
I did a big 3" circle, 100% black 300/300. What’s interesting is that the pattern shows up on the edges. Ignore the gap in the image. I opened the lid, which shuts off the laser. Prior to that I tried some small (1" wide) avengers icons. The photo is below. You see the pattern make an almost circular effect.
I should note that in both these images I have concatenate x turned on.