When you first start using a laser cutter, the software can feel like the cockpit of a small aircraft.
You have Power.
You have Speed.
Then there’s Frequency.
And what exactly are Passes?
Change one number and your material suddenly cuts beautifully.
Change another and you get smoke, scorching, melting, or a line that barely marks the surface.
The frustrating part is that there isn’t one magic set of numbers that works for everything.
A setting that works beautifully on 3 mm plywood might be completely wrong for acrylic. A setting that works on one laser may be unsuitable for another. Even two sheets of supposedly identical material can behave differently.
The good news is that the basic principles are actually quite simple.
Once you understand what each setting does, laser cutting becomes much less about guessing and much more about testing and controlling the process.
Let’s break it down.
The Four Settings You Need to Understand
For most beginner laser-cutting projects, four settings are particularly important:
- Power — how much laser energy is being delivered
- Speed — how quickly the laser moves
- Frequency — how frequently a pulsed laser fires
- Passes — how many times the laser travels over the same geometry
These settings don’t work independently.
They interact.
For example, increasing power while slowing the laser down generally puts more energy into the material.
Increasing speed reduces the amount of time the laser spends over each point.
Adding additional passes gives the material another opportunity to absorb energy.
And frequency controls the pulse behaviour on laser systems where that setting is available.
Understanding that relationship is the key.
1. Power: How Strong Is the Laser?
Let’s start with the setting that sounds the most obvious.
Power controls the laser’s output level.
In many laser-control programs, you’ll see power expressed as a percentage.
For example:
20%
50%
80%
100%
But don’t assume that 50% means exactly half the cutting ability of 100%.
The relationship between the software percentage and actual optical output depends on the laser, its controller and the machine’s characteristics.
So power percentages should generally be treated as machine-specific settings, rather than universal measurements.
Still, the basic concept is simple.
More power generally means more energy is delivered to the material.
That can produce:
- Deeper engraving
- Darker marks
- Deeper cuts
- Faster cutting
- More melting
- More scorching
- More smoke
- Wider kerfs
LightBurn describes power as one of the two primary settings controlling cutting depth and engraving darkness, with speed being the other.
What Happens When Power Is Too Low?
Imagine you’re trying to cut through 3 mm plywood.
You set the power too low.
The laser travels across the material, but doesn’t deliver enough energy to completely penetrate it.
You might see:
- A faint line
- A partially cut groove
- A dark surface mark
- A cut that breaks through in some places but not others
The solution might be to increase power.
But that’s not your only option.
You could also reduce the speed.
What Happens When Power Is Too High?
Now imagine going in the opposite direction.
You use enormous amounts of power.
The laser cuts through—but the edges may become ugly.
You might see:
- Heavy charring
- Melted edges
- Excessive smoke
- Larger kerf
- Discolouration
- Loss of fine detail
For some materials, excessive energy can also produce unwanted melting or other material damage.
So the goal isn’t:
Maximum power.
The goal is:
Enough power to achieve the result you want.
2. Speed: How Quickly Does the Laser Move?
Speed determines how quickly the laser head travels across the material.
Depending on your software and machine, speed may be expressed in:
- mm/s
- mm/min
- inches/minute
- another machine-specific unit
This is extremely important.
For example:
10 mm/s
and
10 mm/min
are very different speeds.
Mixing up units can result in dramatically different laser exposure and can even create dangerous situations if the machine operates much more slowly than intended. LightBurn specifically warns users to pay close attention to speed units when using settings from other sources.
Always check which units your machine uses.
Slow Speed = More Energy
Imagine the laser moving over one particular point.
If the laser moves slowly, it spends more time there.
That means the material receives more energy.
As a general rule:
Slower speed → more heat
Faster speed → less heat
This is why reducing speed can make a laser cut deeper.
LightBurn similarly explains that slower movement delivers more power and heat to a point because the laser spends longer over that area.
Fast Speed = Less Energy
If the laser moves quickly, it spends less time over each part of the material.
This can be useful for:
- Light engraving
- Surface marking
- Minimising heat
- Reducing scorching
- Protecting delicate materials
But if you go too fast, the laser may simply fail to mark or cut the material adequately.
You may see:
“It looks like the laser went over the line, but nothing happened.”
That’s often a speed/power problem.
Power and Speed Work Together
This is probably the most important concept in this entire article.
Don’t think about power and speed as completely separate controls.
Think about them as a pair.
For example:
High Power + Slow Speed
Generally produces a lot of energy.
Useful for:
- Deep cutting
- Thick materials
- Strong engraving
But it can also produce:
- Charring
- Melting
- Excessive kerf
- Burn marks
Low Power + Fast Speed
Generally produces much less energy.
Useful for:
- Light marking
- Delicate engraving
- Surface effects
But it may fail to cut or mark sufficiently.
Moderate Power + Moderate Speed
Often provides a useful starting point.
The exact combination depends entirely on your machine and material.
Think About Energy Per Area
You don’t necessarily need to calculate the physics every time you use your laser.
But it helps to understand the concept.
Suppose the laser travels twice as slowly over the same line.
It spends approximately twice as long delivering energy to that area.
That’s why changing speed can have a dramatic effect even when the power percentage remains unchanged.
This also explains why simply copying someone else’s power setting isn’t enough.
Their:
- Laser
- Lens
- Material
- Focus
- Speed units
- Air assist
- Cutting method
may all be different.
3. Frequency: What Does It Actually Mean?
Frequency is where things become slightly more complicated.
Unlike a continuous-wave laser, many laser systems operate by producing pulses.
Frequency refers to how frequently those pulses occur.
It may be expressed in:
Hz
or
kHz
depending on the machine and controller.
For example:
20 kHz
means 20,000 pulses per second.
But frequency is highly machine-dependent.
It is particularly important on certain pulsed and galvo laser systems, including fiber lasers, and its exact effect varies with the laser source, material, power, speed and other settings. LightBurn notes that lower frequencies generally mean fewer pulses with greater energy per pulse, while higher frequencies mean more pulses with lower energy per pulse.
Frequency Isn’t the Same as Power
This is an important distinction.
Power describes the laser’s output level.
Frequency describes how frequently the laser pulses.
Imagine a water sprinkler.
Power is roughly like the amount of water being delivered.
Frequency is more like how often the sprinkler releases individual bursts.
Changing either one changes how energy reaches the material.
But the exact relationship depends on the laser system.
Why Frequency Matters
Frequency can affect:
- Marking quality
- Material response
- Heat distribution
- Engraving appearance
- Pulse overlap
- Cutting behaviour
- Surface finish
For some applications, changing frequency can make a dramatic difference.
For others, it may have little practical effect.
That’s why you shouldn’t assume:
“Higher frequency is always better.”
It isn’t.
The correct frequency depends on the laser, material and desired result.
Diode and CO₂ Lasers vs Fiber/Galvo Lasers
This is where beginners can become confused.
Not every laser exposes exactly the same settings.
A typical diode or CO₂ hobby laser may have settings such as:
- Speed
- Power
- Passes
- Air assist
A fiber or galvo system may additionally expose:
- Frequency
- Pulse width
- Hatch settings
- Other laser-source parameters
LightBurn’s documentation notes that the settings available depend on the type of laser and operating mode.
So if your diode laser software doesn’t show a frequency setting, that’s not necessarily a problem.
Your machine may simply not expose frequency as a user-adjustable parameter.
4. Passes: How Many Times Does the Laser Cut?
A pass means one trip over the geometry.
If you set:
Passes = 1
the laser follows the path once.
If you set:
Passes = 2
it follows the path twice.
And so on.
Multiple passes can be extremely useful when cutting thicker materials or when you want to reduce the amount of heat delivered in a single pass.
LightBurn specifically notes that lower-powered lasers may require multiple passes to achieve a clean cut.
Why Use Multiple Passes?
Suppose you are trying to cut through a thick sheet.
You could try:
Very high power + very slow speed + one pass
Or you might achieve a better result using:
Moderate power + controlled speed + several passes
The second approach can sometimes produce cleaner edges and reduce excessive burning.
It can also be useful when your laser doesn’t have enough power to penetrate the material in a single pass.
One Pass Isn’t Always Better
It can be tempting to think:
“If one pass is good, one extremely powerful pass must be better.”
Not necessarily.
Imagine trying to cut through plywood with enormous power.
The laser might penetrate quickly, but the surrounding material may receive a lot of heat.
The result could be:
- Burnt edges
- Heavy smoke
- Large kerf
- Excessive discolouration
Multiple controlled passes can sometimes produce a cleaner result.
LightBurn’s documentation specifically recommends considering multiple passes when increasing power would otherwise produce excessive scorching or melting.
But Don’t Automatically Add More Passes
There is another trap here.
If your laser doesn’t cut through in one pass, you might think:
“I’ll just use ten passes.”
That can work.
But it isn’t automatically the best solution.
Every pass adds another opportunity for heat to build up.
Too many passes can lead to:
- Excessive charring
- Wider kerf
- Melted edges
- Loss of detail
- Longer cutting times
So again, you’re looking for a balance.
The Big Four Work Together
Let’s put the settings together.
Imagine you’re cutting plywood.
You have:
Power
Speed
Frequency
Passes
Changing any one of them can change the result.
For example:
Increase Power
More energy per unit of time.
Potentially deeper cutting.
Potentially more burning.
Reduce Speed
More time over each point.
Potentially deeper cutting.
Potentially more burning.
Increase Passes
More total exposure.
Potentially deeper cutting.
Potentially more heat accumulation.
Change Frequency
Changes pulse behaviour.
Potentially changes marking or cutting characteristics depending on the laser system.
This is why laser settings can feel complicated.
You’re not really setting four independent controls.
You’re controlling how energy is delivered to the material.
What About Air Assist?
Although it isn’t one of the four settings in this article, air assist deserves a mention.
Air assist directs a stream of air toward the cutting area.
It can help:
- Remove smoke
- Clear debris
- Improve cutting
- Reduce flare-up risk
- Reduce some forms of scorching
- Keep the lens cleaner
Air assist can therefore change how a particular power/speed combination behaves.
This is another reason why copying someone else’s settings isn’t always successful.
Their machine may have air assist enabled while yours doesn’t—or vice versa.
Always follow your laser manufacturer’s safety and operating instructions.
Focus Matters Too
Before you start changing power and speed, make sure the laser is properly focused.
A poorly focused laser spreads the energy over a larger area.
That can produce:
- Wider cuts
- Less precise engraving
- Reduced cutting ability
- Poorer detail
If your settings suddenly seem terrible, don’t immediately assume the power or speed is wrong.
Check:
Focus
Material position
Lens condition
Material flatness
Air assist
Machine alignment
Sometimes the setting isn’t the problem.
Why There Are No Universal Laser Settings
You’ll often find tables online saying things like:
3 mm plywood — 70% power — 15 mm/s
That can be useful as a starting point.
But don’t treat it as a guaranteed recipe.
A laser setting depends on things such as:
- Laser type
- Laser power
- Material
- Material thickness
- Material composition
- Focus
- Lens
- Air assist
- Kerf
- Speed units
- Number of passes
- Machine condition
LightBurn’s own documentation makes this point clearly: speed and power vary substantially between machines and materials.
A 50 W CO₂ laser and a 10 W diode laser are not going to behave the same way.
Neither will two different sheets of plywood necessarily behave identically.
Start With a Material Test
One of the smartest things you can do is create a material test grid.
Instead of randomly changing settings, create a grid containing different combinations.
For example:
| Low Power | Medium Power | High Power | |
|---|---|---|---|
| Fast | Test | Test | Test |
| Medium | Test | Test | Test |
| Slow | Test | Test | Test |
You then cut or engrave the grid.
You can visually compare the results.
For cutting, you’re looking for a combination that cuts reliably without unnecessarily damaging the material.
For engraving, you’re looking for the desired darkness and depth without burning too deeply.
LightBurn provides a Material Test tool specifically for exploring combinations of speed and power.
What Should You Look For?
For cutting, examine:
- Did it cut all the way through?
- Are the edges clean?
- Is there excessive charring?
- Is the kerf consistent?
- Did the material melt?
- Is the underside heavily burnt?
- Did small details survive?
For engraving, examine:
- Is the mark dark enough?
- Is it too deep?
- Are the edges sharp?
- Is the surface burnt?
- Is the shading consistent?
- Are fine details still visible?
Don’t simply choose the setting that produces the darkest mark.
Choose the setting that produces the desired result.
A Simple Example: Cutting 3 mm Plywood
Imagine you’re working with 3 mm plywood.
You run a test and discover:
Fast + low power: Doesn’t cut through.
Medium + medium power: Almost cuts through.
Slow + medium power: Cuts through but produces significant scorching.
Medium + slightly higher power: Cuts through with cleaner edges.
The last combination might be the better starting point.
But then you try:
Slightly faster + slightly higher power
and discover that it still cuts through while reducing the heat delivered to the material.
That’s the kind of optimisation you want.
You’re looking for the lowest energy combination that reliably produces the result you need.
LightBurn similarly recommends looking for the lowest power and highest speed that reliably cuts through when optimising cutting settings.
A Simple Example: Engraving Wood
Now imagine engraving a logo onto plywood.
You don’t necessarily want maximum power.
You want:
- A dark mark
- Sharp edges
- Consistent depth
- Minimal charring
So you might experiment with:
Higher speed + lower power
versus:
Lower speed + higher power
Two settings might produce equally dark marks.
But one might leave a much cleaner surface.
That’s why testing matters.
Cutting vs Engraving
It’s also important to understand that cutting and engraving are fundamentally different jobs.
Engraving
The laser modifies the surface.
You generally want:
- Controlled energy
- Fine detail
- Consistent depth
- Controlled darkness
Cutting
The laser needs to remove enough material to penetrate the sheet.
You generally want:
- Sufficient energy
- Reliable penetration
- Clean edges
- Controlled kerf
So don’t assume that a good engraving setting will make a good cutting setting.
It won’t.
Why Slowing Down Isn’t Always the Answer
A common beginner troubleshooting technique is:
“It didn’t cut, so I’ll slow it down.”
That can work.
But eventually you’ll reach a point where you’re simply dumping too much heat into the material.
You may get a cut—but an ugly one.
The better approach is to test the relationship between speed and power.
For example:
Instead of:
Very slow + very high power
try:
Moderate speed + moderate power
or:
Higher speed + somewhat higher power
You may find a combination that cuts just as effectively with less scorching.
Why Increasing Power Isn’t Always the Answer
The same principle works in reverse.
If the laser isn’t cutting, don’t automatically increase power to 100%.
Try adjusting speed.
Try additional passes.
Check focus.
Check air assist.
Check whether the material is actually suitable for your laser.
A clean cut is usually the result of several factors working together.
Frequency Testing
If your machine provides adjustable frequency, treat it as another variable to test rather than assuming one value is universally correct.
You might create a test grid containing:
- Different frequencies
- Several power levels
- Several speeds
Then examine the results.
LightBurn recommends material testing when experimenting with frequency and other laser-source parameters because the effects vary considerably with the laser and material.
For a beginner, however, don’t get distracted by frequency if your machine doesn’t require you to adjust it.
Start with the settings your machine manufacturer recommends.
Keep a Settings Library
This is one of the best habits you can develop.
Every time you discover a good setting, write it down.
For example:
| Material | Thickness | Speed | Power | Passes | Result |
|---|---|---|---|---|---|
| Birch plywood | 3 mm | 18 mm/s | 70% | 1 | Clean cut |
| MDF | 3 mm | 15 mm/s | 65% | 1 | Slight edge burn |
| Acrylic | 3 mm | 12 mm/s | 60% | 1 | Clean cut |
| Cardboard | 2 mm | 40 mm/s | 25% | 1 | Clean cut |
These are example records, not universal recommended settings.
Your own machine should generate your own numbers.
Also record:
- Laser model
- Material supplier
- Actual material thickness
- Air assist setting
- Focus method
- Lens
- Date
- Number of passes
- Notes about the result
Eventually you’ll have your own material database.
That is much more useful than constantly searching the internet for somebody else’s settings.
Change One Thing at a Time
Here’s a simple rule that will save you a lot of frustration:
Don’t change five settings at once.
Suppose your cut doesn’t work.
You change:
- Power
- Speed
- Frequency
- Passes
- Focus
Then the next cut works.
Great.
But you don’t know why.
Was it the power?
The speed?
The focus?
The extra pass?
You haven’t learned anything useful.
Instead, change one variable at a time whenever practical.
For example:
Test 1: 60% power, 20 mm/s
Test 2: 65% power, 20 mm/s
Test 3: 70% power, 20 mm/s
Now you can see what changing power did.
Then you can test speed.
This is much closer to proper experimentation.
The “Too Much Energy” Warning Signs
Your material is probably receiving too much energy if you see:
- Excessive charring
- Melted edges
- Heavy smoke
- Large kerf
- Loss of fine details
- Deep unwanted engraving
- Warping
- Severe discolouration
Your first response shouldn’t necessarily be:
“Turn the power down.”
Consider the whole system.
You might:
- Increase speed
- Reduce power
- Reduce passes
- Improve air assist
- Improve focus
- Change the material
- Adjust frequency where appropriate
The “Not Enough Energy” Warning Signs
You may not be delivering enough energy if:
- The material doesn’t cut through
- Engraving is barely visible
- Lines are inconsistent
- Parts remain attached by thin fibres
- You need excessive manual finishing
Possible solutions include:
- Increase power
- Reduce speed
- Add a pass
- Improve focus
- Check air assist
- Check material thickness
Again, don’t change everything at once.
Don’t Forget the Underside
A cut can look perfect from the top and still have a problem underneath.
Look at both sides.
Heavy residue on the underside can indicate that the material is receiving substantial heat.
A honeycomb bed or suitable cutting surface can also affect how the underside behaves.
This is particularly important when you’re trying to produce professional-looking products.
Your Goal Isn’t Maximum Cutting Power
This is perhaps the biggest mindset shift for beginners.
You aren’t trying to make your laser work as hard as possible.
You’re trying to make it work efficiently and consistently.
The ideal setting is often something like:
Enough energy to do the job + enough speed to avoid unnecessary heat.
That can produce:
- Cleaner edges
- Better detail
- Less smoke
- Less scorching
- More consistent dimensions
- Longer material life
- More repeatable production
A Beginner’s Troubleshooting Chart
| Problem | Things to Check |
|---|---|
| Doesn’t cut through | Increase power, reduce speed, add a pass, check focus |
| Heavy charring | Increase speed, reduce power, improve air assist |
| Engraving too light | Increase power or reduce speed |
| Engraving too deep | Reduce power or increase speed |
| Acrylic melting | Reduce heat input, increase speed, review power |
| Uneven cutting | Check focus, material flatness, alignment and settings |
| Very wide kerf | Reduce excessive heat and check focus |
| One area doesn’t cut | Check material flatness, focus and machine consistency |
| Lots of smoke | Check air assist and ventilation |
| Results vary between sheets | Measure material and test each material batch |
The Best Workflow for Dialling In Settings
When working with a new material, try this process.
Step 1: Identify the Material
Don’t simply write:
“Wood.”
Write:
“3 mm birch plywood.”
The more specific you are, the more useful your settings database becomes.
Step 2: Measure the Material
Use digital calipers.
Don’t rely entirely on the manufacturer’s nominal thickness.
Step 3: Check Focus
Make sure your laser is correctly focused.
Step 4: Start Conservatively
Use manufacturer recommendations or a trusted machine-specific starting point.
Don’t immediately jump to extreme settings.
Step 5: Run a Test Grid
Vary power and speed.
Step 6: Examine the Results
Look at:
- Top surface
- Bottom surface
- Edge quality
- Kerf
- Burn marks
- Cut depth
Step 7: Test Passes
If necessary, compare:
One pass
against:
Two passes
or another sensible number.
Step 8: Test Frequency if Your Machine Uses It
If frequency is available and relevant to your laser system, test it rather than assuming a generic number is correct.
Step 9: Record the Result
Save the successful settings.
Step 10: Test Again When Conditions Change
If you change:
- Material
- Thickness
- Laser
- Lens
- Focus
- Air assist
- Cutting settings
you may need to retest.
Build Your Own Material Library
Eventually, you’ll have something much more valuable than a random collection of numbers from the internet.
You’ll have your own tested settings library.
For example:
3 mm Birch Plywood
Cut:
Speed: ___
Power: ___
Passes: ___
Air assist: ___
Engrave:
Speed: ___
Power: ___
Interval: ___
3 mm Acrylic
Cut:
Speed: ___
Power: ___
Passes: ___
Engrave:
Speed: ___
Power: ___
Interval: ___
And so on.
Over time, this becomes one of the most useful resources in your workshop.
The Golden Rule: Test, Don’t Guess
Laser cutting settings can initially seem mysterious because there are so many variables.
But once you understand the basic relationships, it becomes much easier.
Power controls how much laser energy is delivered.
Speed controls how quickly the laser moves across the material.
Frequency controls how frequently pulses are delivered on laser systems where that parameter is available.
Passes control how many times the laser travels over the same geometry.
And all four can interact with:
- Material
- Thickness
- Focus
- Air assist
- Laser type
- Machine configuration
The secret isn’t finding somebody else’s “perfect” settings.
The secret is learning how to find your own.
Run a material test.
Change one variable at a time.
Record what happens.
Build a settings library.
And don’t be afraid of a little experimentation.
That’s how you go from:
“Why isn’t this cutting?”
to:
“I know exactly what this material needs.”
And once you reach that point, your laser cutter becomes much more predictable, much more useful—and considerably more fun to use.
