Materials/Library settings

I am new to LB and wanted to start saving settings so I dont have to rediscover good material setting once I have them.
In finding a good engraving setting to mark work on manila paper I realized my old method of setting the power on the K40 and using 100% in the software was silly because it mean wear and tear on the K40 switches.
So I set up a test and thats when I noticed using 12% on the K40 gave me uniform lines BUT 100% K40 with 12% in LB causes the corners of projects to be dark and show artifacts that do not show in the cut at high power or low power etches.
Whats going on?

100% on the K40 power supply is not where it should be - You should adjust the K40 power so that a test fire gives you the desired tube output current (12ma to 15ma) and leave it there.

Likely the reason you are seeing burnt corners is that at 12% in LightBurn, you have a much narrower range of available power output values. The Smoothie board uses 10 bit PWM (I believe) meaning it has 1000 possible output power values. If you set the layer to 12%, you only have 120 possible power values to use now when varying the power to slow down for corners, and this might not be enough.

Are you doing vector marking, or engraving (fills)? If you are using the Fill setting in LightBurn, be sure to turn on Overscan as well - this will let the controller overshoot the edges of the fill before stopping completely, reducing the edge burn.

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First off with a digital power adjustments there is no way to know the actually number of milliamperes involved AFAIK.
Second, you say set it and leave it and then not to use a low power LB settings, how does one then do light engraving?
Also 12% on the K40 power setting panel is my lowest to get the laser to fire. So having LB be limited to 120 values seems worthless as the laser wont fire if it reduces power.
My use is vector marking(I assume, I just think of what I’m doing as a low power test pass) so I know if I’m getting what I intend as to size, position etc
But all my jobs are full cutting job, no engraving. My test marking is done on manila folder paper.

I appreciate you input but I’m clearly not getting what you are saying.

You must add a mA ammeter, that is if you wish to protect your laser tube and to know what’s really going on under the hood. you might find this thread relevant:

I agree on the need for an analog MA meter. I think I have room for one too.

My take is for now I should use a DVM to measure current at different settings to find what ma = % setting. Then set the K40 panel to the desired maximum. I see lots of mention of 18-20 ma and other who say lower. My seat of the pants guess is given a 16kv supply at 20ma is 32watts and that should be pretty close to safe as far as immediate damage, with 15% perhaps a good number for getting long tube life. So thats my plan for today.
analog meters are cheap so I’ll order one up so I can see the actual power and observe PS issues, I understand at lower setting its not very stable.

I have in fact enabled the test fire button, but for me kind of silly as my LB PC is in another room. Since I have to go to the laser to see if it fired, I might as well use the K40 test fire button or the GLCD control- which appears to override the K40s power settings. I also wonder about the GLCD power scale setting. I’ve had my K40 for a few years but there are so many things to mess with, and I spend my time actually using the machine vs experimenting endlessly. That said, I will research and test the GLCD features.

So I guess the answer is if I set the K40 at 12% and LB at 100% then LB handles reducing power where the head is moving slowly so the result is consistent cuts vs doing 12% in LB where it can not reduce without causing the laser to not fire, which it seems would be the case but is not what I see.

I should add that I do not actually use 100% power, when I set it to max, I use the cutting software to lower it.

The advice for an amp meter is even better than I thought- turns out 65% on the digital power setting is 18ma. So in the early days with stock mirrors I was definitely running over that. Now that I have a meter installed and new mirrors I can keep it at a reasonable setting. THANKS GUYS!

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What mirrors did you go to?

Made a really big difference. I think a larger focus lens will help too, although I suspect it will be a smaller increase in performance

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