Quick question for all the laser folks out there. I am finally starting to play around with the 45w laser on my 48x48. I am very new to this and tried some text and graphics today on a small maple plaque. As you can see, I am getting the overburn marks around everything I laser. I am trying to get a very dark etching so I was running the toolpath at 70% power and 90ipm with a 45 deg crosshatch pattern.
This is not deep burning and sands off easily, but I would like to know what the best practice is since I am just learning the process. Not sure if this is a speed/power issue or if I need to put down masking tape or Oramask to keep it from happening. On a side note, the first pass does not seem to burn so much but when it comes back for the cross hatch that’s where most of it seems to come from. Any suggestions would be appreciated. Thanks….Rick
These are the setting I went with. I did start out at about 30% power with some faster speeds but I was only getting the brown looking text and not the deeper black like I got when I slowed it down and increased the power. Not sure if there are other ways to get that rich black looking laser texts. Mayber faster speed but multiple passes? As for the air assist, and again sorry since I am new to the laser world, but is that doing this with the round knob on the top of the laser or do you mean from the controller box?
Like with router feeds and speeds this is pretty unique to every piece of wood/setup…
My guess here is that you’re moving too slow and have your power up too high, and/or your air assist is not strong enough. You can adjust the air assist with that little knob. If you want to test air assist before you cut (and fool with the knob) you can go to UTILS/LASER UTILITIES and deploy the laser. When you do that will activate the air assist.
My advice to you is use that chart that I linked in the previous post and just do some tests on some similar scrap. You may find that a feed/power combo works in a way you didn’t expect, or that doing two light passes is better than one slower/stronger pass.
70% is cutting power for that laser. As Eric, said its a tradeoff between speed and power. However, for vector burning where you are just tracing vectors back and forth to fill in areas, you usually have very short vectors (like well under 0.25” long). So most of the time you really can’t achieve high speeds because the motion controller manages accelleration at the beginning and end of vectors to smooth out the jerkiness of the motion. This means on very short vectors, you are either slowing down or speeding up, but not actually running at the full programmed feedrate. This is bad for laser work because then you don’t have a consistent speed. The laser software does have a linear compenstation for the power vs. speed, but that really is only meant to handle the spots where the speed is nearly zero and its changing directions, you shouldn’t count on it over the whole project’s area.
So I generally keep my speed down to around 50-60ipm for most lettering projects or ones with fine detail. Then I will use power to define my depth of etching/color. For that laser, 15% power at 50ipm and full crosshatch fill (with around 0.008 step over for the smoothest fill) should give very dark results, probably will actually etch pretty deep. Adjust as needed from there.
I use the same settings and techniques as Jim, they work very well. No matter what though I always have some impact on the wood from the burning/smoke which is sand off as mentioned.
Get a roll of masking paper - lightly glued paper on one side - cover the wood and you will never see over burn - when engraving, or even when cutting thru the wood which produces the most over burn. Also, there are pre masked laser materials - wood, plywood, acrylic, etc from many suppliers. GlowForge is one site that sells these materials.
Thanks to all for the suggestions. I did end up using some blue tape for this since I was in a crunch for time but I will try the tips that were given. I have some leftover maple from this project so I’ll probably just set it up to run lines of text at various speeds and power to see where the sweet spot is. It came out pretty good for a first try. Thanks again for the help…Rick
