75 lpi is lighter than 125 lpi. Why?


#1

So I’m trying to speed up my prints - but with the same level of detail (relatively).

I followed some advice to go from auto PG engrave to manual settings.

I keep speed at FULL and power at FULL and am playing with the lpi. When I engrave at 75 - I can see the actual lines - which is not the end of the world, but the overall design is lighter. When I engrave at higher lpi, the design is darker -

Is this because the closer lpi actually start to run into each other and take away more PG maple and then they have the space to go LOWER into the wood?

Is there a way to make 75 LPI but have it go LOWER of an engrave into the wood?

I guess I’m asking about z axis also in this post. Thanks for any insight you might have!


#2

Lower the speed. Slower means the beam stays in one spot longer and burns deeper and slightly wider.


#3

Wood gets darker the longer it is heated, the oils or sugar in it are what change colour. So with more LPI they are being heated for longer and get darker that way.


#4

So the speed makes it darker - but obviously the prints will take longer…

Are these the two things you play around with more or less when going manual? The convert to dots or patterns seems a little weird - the prints look very different.

I never tried speed - but will try it now - thanks!


#5

Yes, this is perfectly normal behavior. Fewer lines, less burn. Everything is a trade off. You can up the power if you are not already at full, or you can slow down some.

Besides the built in things play with filters in GIMP or Photoshop to get just the look you want and max speed.


#6

Are people mass producing always lasering at full speed thought - in terms of economy of scale?


#7

Well, they are lasering at the max speed that they can get the results they want.
I love my :glowforge: but if you want 700 of the same thing and do runs like that all the time you might tip the scale toward a faster machine. The :glowforge: is what I’d call a prosumer machine, good for prototyping and small runs but routine runs of large numbers of the same thing can justify a truly professional unit pretty quickly.
It is a lot like my 3d printer. It is great but when I come up with that thing that everyone will want it will be time to injection mold!


#8

I futz with the power and lpi and dots and photoshop with engraving, to ALWAYS run at full speed. Engraving, even at full speed, is mind numbingly slooow. 'Tis the nature of the tool. You CAN get good results, but usually not on the first try. (I’ve been pretty lucky finding good settings/images 2nd or 3rd try. Even got a couple first try.) @markevans36301 hit the nail squarely with mass production. I recently did 250 festival tags, like 1.25" x 3"… all engraved… did 100 at a makerspace with a dual 75W Universal, took about 3 hours. 150 on the GF took over about 9. BUT, it’s in my basement, so there is that trade off of being able to do other things.