How do all the power settings effect each other?

I’m learning to use my Sculpfun laser cutter and I went through their documentation here (which is very good, by the way!):

They refer to a test file from hobbylasercutters, which I’ve used for my tests. Here’s the direct link:
https://wiki.the-iskens.com/wp-content/uploads/2022/03/LightBurnS6S9TestfileCorrected.zip

This test file ran as expected. But when going through the online LightBurn documentation, I couldn’t see how the test file was able to change the power of a single layer for multiple objects. I finally just right-clicked a shape and discovered that you can set the power level on a layer’s shape too.

I’ve also seen the following other power settings:

  • S-value Max in the Device settings
  • Power Max in the Layer settings
  • Max Power in the Sub-Layer settings
  • Possibly even more!

I’m now curious how all these values interact with each other.

Do they override, and if so, what order is the override?
Or, are they fractions of a fraction, and if so, what is the heirarchy?

Nice question! If you click on the Layers it appears they are all sharing the same parameters.Click on one of the designs. Now right-click and select Properties. That is where the design gets it individuality.

As you can guess, it takes a lot of time to build one of these, especially as complex as this one is. It is sort of a one size fits all. You can also just use the Lightburn Material Test, or even build a simple one for your specific needs.

Congratulations on discovering Melvin’s ( @misken ) wiki site (https://diode-laser-wiki.com/). Although it mentions Sculpfun, 90% of that material applies to all of the diode lasers. There is nothing else “laser” like it anywhere else on the internet. If you use it a lot, drop him a donation or two.

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Welcome to the forum Kirk :slight_smile:

S-value Max in the Device settings

See:

This setting tells LightBurn how to represent 100% power when it’s talking to the machine, because the firmware at the motion controller has it’s own numeric scale for power, usually 0 to 1000, or 0 to 255 - for more info look at the GRBL setting for $30.

So if ‘S-Value Max’ is 1000 and you set max power to 100% in the layer settings, LightBurn will know to send ‘1000’ to the controller, and if you set it to 50% LightBurn will send ‘500’.

My S-Value max is set to 1000, because my $30 GRBL setting is also 1000, but I’m guessing I could could probably change them to 1023, to take advantage of the 1024 levels of power that can be represented by a 10bit PWM signal, but that’s splitting hairs!

There is no hierarchy relating to power % with sublayers, what is set as max power % in the sublayer will be what is sent for that layer (there is no overriding power % control for a “Multi” layer that affects all sub layers).

If you set the power % on an individual shape to anything other than 100% that shape will only get a percentage of the power set at the layer - so if the layer power was set to 50%, and the shape was also set to 50%, that shape effectively only gets 25% power.

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