Diameter of this Epilog Fusion Edge CO2 laser?

I’m using my local maker’s space Epilog Fusion Edge 24 CO2 cutting laser to cut pieces out of 1/8" Basswood plywood and I’m trying to figure out how much material it will remove. I’m assuming the diameter of the laser is about what it will remove if cutting a straight line.

The info on the company website lists the laser source for this model as ‘50 or 60 watt, air-cooled, metal/ceramic tube, 10.6 micrometers.’

Now is that 10.6 micrometers the laser diameter or possibly it’s wavelength?

What you’re wanting is called kerf. It will vary between different materials. You will need to conduct tests with your material to determine the speed and power needed to cut and then you can figure out what the kerf is for that material. The slower you run the laser or the higher the power the wider the kerf will be.

Think about it, you are burning wood with the beam, so the more contact time or the hotter it is the more material is removed.

10.6 microns is the wavelength on an Epilog Fusion Edge 24 CO2.

I am assuming that the makerspace laser has a standard 2" lense. Like @thelmuth said, the kerf depends on the speed and power. You can also set the frequency of the pulse with an Epilog.

You set those values in the Epilog Dashboard software. But, Epilog has default choices for certain materials and thicknesses. A good place to start for 1/8" wood is below:


Having said all of this, if you want an easy way to determine the kerf or the beam thickness on this specific laser for your 1/8" basswood plywood, create a 1" x 1" square, and use the default settings above.

Assuming you get a clean cut without charring, take a caliper and measure the square. Assuming it measures 0.990" x 0.990", the beam width or kerf is 0.010". If you want the finished size of the square to be 1", you would offset each edge by 1/2 the beam width, or 0.005" per edge. The square would now be designed at 1.010" x 1.010"


The quick-n-easy way to measure kerf:

As @thelmuth points out, you must run that test for each material you use.

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That tool will work for an Epilog, but LB doesn’t drive that laser. You would need to export the LBRN file to SVG or AI, and import it into Illustrator or CorelDraw. Epilog’s are higher end lasers, and they cut accurately. I use a similar laser - Universal Laser Systems VLS6.60 with a 1.5" lense. Cutting a 1" square and measuring with a caliper is “good enough” for me :slight_smile:

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I figured because the question came up here, on a LB forum, then OP had already figured out how to get designs from LB to Epilog.

Verily, there’s a time for every style … :grin:

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Sorry to confuse ednisley. I’m liable to show up anywhere on the interwebs asking my questions.

Thanks so much RalphU for that picture and settings. So I should first set it on 20% speed, 100% power and 10% frequency and see what happens. I’m curious how frequency would effect the cut. I understand about speed and power already, but not frequency, if anyone could please explain?

Also, how would you begin adjusting those values depending on what happens as it’s cutting?

The frequency is related to the number of pulses per inch. You can vary it, but Epilog has some basic defaults for material thickness. You can increase the percentage frequency, but I would tend to use a number similar to what Epilog defaults to.

Regarding speed and power, you want to be able to get a clean cut with no scorching. It is ok to run an Epilog at 100% power, and you then just vary the speed to get it to cut thru. If you aren’t in a hurry, you can cut 2 passes with more speed and less power. You have to decide what works best for your material.

Yes, because the RF laser is a digital device, it will only lase at 100%, like an led.

A glass tube is an analog device.

As a mention, pwm is frequency independent, instead of frequency, it should be referred to technically, as period.


Not sure what you mean by it will only lase at 100%. You can run an RF laser at any power percentage you choose.

What power measurements are you referring?

An LED and your RF laser is turned on when the pwm goes active, it is on at 100% power during that pwm on cycle.

The power you’re referring is power/time, just like a ssl (diode).

A glass tube laser can run at 50% power a 100% of the time → an RF (or ssl) laser, it runs 100% power for 50% of the time (period) for the same 50% power setting.

This is one of the reasons rf lasers have a higher beam quality (M2), resulting in higher quality spot and smaller smaller in size. A higher quality beam is usually associated with the high end power of the tube.

It’s also the reason that changing period has the effect it does of changing the machines ppi

I’d love to have one… signed → envious:joy_cat:


I have a 1.5" lense on a Universal Laser Systems VLS6.60. When I cut cardstock ( which is about 0.012" thick) you can barely see the beam.

You can get the Thunderlaser Bolt that comes with a 30watt RF tube and runs LB :slight_smile:

If you’re seeing the ir beam, your eyes are better than mine… lol…

I know what you mean… I think we’d have a homicide if I ask the spouse, whose planning retirement, for another laser, the fiber isn’t paid off…

I’d love to have one, but I think it’s a pipe dream for me… :man_shrugging:

Do you know if you have a beam expander in your machine?

Do they give you the output beam diameter anywhere in the documentation?

Using some of the on-line spot size or dof calculators, the beam diameter is a critical number to know for most if not all calculations. Do you have any manuals or anything on the actual RF module itself?


No need to get yourself into trouble. Sounds like you already have some nice “toys”.

Yes, my machine has a beam expander. ULS claims that my 1.5" beam diameter is about 0.003".

Universal has another lense they call HPDFO, with a smaller diameter than mine. I know someone who cuts paper similar to what I do, and that is what they use.

This link is for the user manual. My 6.60 is a discontinued model, but pretty similar to the newer 6.75.

I’m wondering what size the beam emitted from the expander is… this is the input beam going to the lens.

I looked at the posted link, but it didn’t give laser source or expander output in the specifications.

Might be a good question for them, a manual of the rf source module or at least the output diameter and the multiplication factor of the beam expander. In fact any manual is a good idea, especially if the device is being phased out.

For them to advise you that your spot size is 0.003" (0.0762mm) they have to know the input beam size. If the spot is that size, it should be possible for you to get 333.33 dpi?