LPI on Proofgrade Maple Ply


#1

@Jules mentioned that they start large engrave projects at 225LPI on wood, because at 340 and higher, the laser is just scorching into the lines previous and you’re not really getting more details, just more scorching and deeper engrave. I’m just wondering why the GF team has the proofgrade settings for Maple Ply at 450LPI for simple graphic engrave? Does that mean the most optimal engrave will be 450LPI or should I drop it to 340 and override the PG settings when engraving?


#2

That’s just my opinion @ryanjpedersen, others will no doubt tell you that 450 LPI is necessary for a more attractive engrave. :wink:

And they have to set their default settings for the “most used” scenario - that might be smaller engraves for medallions and such…when we start getting into larger engraves, it’s getting into more advanced work.

It only becomes necessary to lower the LPI when you’re doing a really large surface area engrave - it cuts way down on the data that can hang up the file in the buffer. So they might choose to leave the higher LPI value in there.

(You can just do a couple of tests on small squares and see which one you like better.) :slightly_smiling_face:


#3

Thanks!


#4

good to know … the file that keeps choking my GF is using maple ply settings. maybe if i lower the dpi i’ll have more luck.


#5

FYI i just tried this on the file that kept failing (changes the dpi from 450 to 270) and the file is now running.


#6

Great! :grinning:


#7

@ryanjpedersen

@jules is right. I was trying to engrave a photo in some maple ply, and it kept looking like an unformed blob until I turned to LPI down. Notably, it would look OK at first, but after a few minutes the sap or whatever is released by the heat from the laser would ooze out enough to ruin it,


#8

To a rough first approximation, the cutting kerf is 0.008", which corresponds to 125 LPI. So it makes sense that marking the surfaces would be less than that, but not by a huge amount. The higher LPI numbers give you less stairstepping and other raster artifacts while burning deeper (which could be useful for really serious 3D engraves in some materials).

I’ve found that when I up the LPI past about 150 I have to reduce the power at least proportionally.


#9

@paulw’s answer is excellent.


#10

Basically cribbed from everybody else, but in one place.