LightBurn Tutorial 03 – Cut Settings

0:00in this video we’re going to look at the

0:03various cut settings in light burn and

0:05how to use them to accomplish various

0:08things there’s some misinformation out

0:14there regarding various cut settings

0:17you’ll hear terms like vector engraving

0:19image engraving marking cutting they’re

0:22all just different ways of controlling

0:26the power to the beam of your laser

0:28cutting is pretty obvious cutting if

0:31this is the material that like side view

0:33of your wood for example cutting is

0:35basically firing the laser strong enough

0:38to cut all the way through it it’s

0:41pretty forgiving if you overpower it

0:44you set the laser power too high it

0:47doesn’t really matter you’ll burn your

0:48edges a little bit but it’s not that big

0:50a deal it doesn’t require a lot of

0:52finesse cutting is pretty

0:53straightforward and it’s very obvious

0:54when you’ve done it wrong if you don’t

0:56cut all the way through you can run

0:58another pass that’ll usually fix it

1:00engraving is one of those things where

1:02you’ll hear a bunch of different terms

1:04so we’ll try to break those down

1:06engraving and marking are essentially

1:09the same thing marking is cutting only

1:12partway into the surface of the material

1:14engraving is the same thing you’ll hear

1:17two different kinds of engraving one is

1:19called image and raving one is called

1:21vector engraving they are both doing

1:25basically the same thing

1:27however vector engraving is using a

1:31shape for example if I make a circle or

1:34a piece of text vector engraving would

1:38be filling this text by or this shape by

1:43scanning the laser back and forth

1:45generally speaking engraving is done by

1:48scanning the laser back and forth across

1:50your image across your vectors or shapes

1:53whatever they are and applying power

1:56where those vectors are are filled or

1:58closed so if I select these items here

Video Transcript for LightBurn Cut Settings (Cont…)

2:02and I say I want to scan these if I

2:06preview this you can see all of these

2:08shapes are now filled except for where

2:11these overlaps we’ll talk about that a

2:12little later

2:13but you remove these so these are now

2:18filled shapes the red is showing late

2:21burn moving between these shapes those

2:25are just traversal moves I turn those

2:27off this is basically what your laser is

2:29going to produce if you zoom in on this

2:31this isn’t actually filled these are

2:34lots of tiny little lines and you can

2:38see if I turn on the traversal moves the

2:42laser moves along this line turns off

2:45jumps to the next line moves down this

2:47way jumps to the next slide moves down

2:49this way and so on when it gets down

2:51here jumps across all the way over here

2:54to this letter s jumps down to this

2:56shape so on and so on and so this is

2:59called scanning raster scanning raster

3:01engraving vector engraving there’s a

3:03whole bunch of different words for it

3:05and they all mean exactly the same thing

3:07raster is a term that dates back to the

3:11beginning of television television uses

3:15what’s called a raster scanning beam or

3:17a raster scan that’s the beam that scans

3:21across the surface of the television

3:22that excites the phosphors on the front

3:27of the screen it makes them light up

3:28that’s why you’ll hear the term raster

3:30it used to describe this kind of pattern

3:34when firing your laser it’s not really a

3:38television anymore but it’s doing

3:40basically the same thing it’s scanning

3:41back and forth turning on and off as it

3:43goes to cut vector engraving is pretty

3:47much just this it’s taking a vector

3:49shape and moving the laser back and

3:53forth across the shape turning it on and

3:54off to engrave or mark the surface of

3:58your material so to do that you would

Video Transcript for LightBurn Cut Settings (Cont…)

4:00generally use high speed and low power

4:04lower medium power and this depends

4:07depending on how fast you’re making the

4:09laser go if I crank the speed all the

4:10way up to 500 millimeters a second for

4:12example I might need to turn the power

4:14up in order to cut deeply enough for

4:18this to really show well totally depends

4:22on the laser the power you’re using the

4:23ability of your hardware but generally

4:25speaking fast

4:27moving faster reduces power in the same

4:31way that lowering your power reduces

4:33power if you run the same cut at the

4:35same power setting but faster you

4:37deposit less heat on the surface of

4:40their material if you run the same power

4:43but slower you deposit more heat on the

4:46surface of your material there’s another

4:48setting that affects how these things

4:51work and that’s called

4:53interval this is also referred to as dpi

4:57or lines per inch dots per inch interval

5:01in this case is how far apart these

5:03different scan lines are so if I bring

5:05this back up in the preview the spacing

5:09of these lines how far apart each of

5:11these horizontal lines is that’s my

5:13interval if I take this number and I

5:16double it up to point two there are

5:20fewer of these vertical or horizontal

5:23lines so if you look at how many there

5:25are at the beginning of this T for

5:27example if I put this number back to

5:30where it was and preview that again you

5:35can see there are many many more of them

5:37if I lower this down to one millimeter

5:40interval so that’s one millimeter

5:42between those scan lines now it’s pretty

5:45obvious there are far fewer of them this

5:49controls the quality of the output

5:51it also affects how much heat is

5:53deposited on the material you’re cutting

5:55the lower interval setting means the

5:59lines are packed closer together it

Video Transcript for LightBurn Cut Settings (Cont…)

6:01means to get a more well-defined curved

6:03shape so for example if you look at this

6:06s if I set this to one millimeter and

6:11preview that if you look at the s it’s

6:14very very coarse there are only a few

6:16lines that are defining the shape of

6:18that mess I drop this down to 25 now

6:24there are twice as many points defining

6:26the curvature of that s I drop this down

6:28to point one and actually do it

6:35and there we go many many many more

6:39lines they’re much closer together much

6:41less or much more overlap between the

6:44individual lines so this plays into the

6:47quality of your engraving and this will

6:49affect image engraving or vector

6:51engraving

6:52it only affects things that are scanned

6:54if I say I want this cut if I want to do

6:58a light surface marking of these shapes

7:00I can use the same speeds and powers as

7:04I would use for regular engraving just

7:07say what this cut cut and mark is the

7:09same thing the only dirt the only

7:12difference between them is that one’s

7:13going to punch all the way through your

7:14material and the other one is not if I

7:17just say cut it’s going to run along the

7:20outlines of these shapes not scan fill

7:23them and you can see here if I follow

7:27the preview it’s just doing the outlines

7:30there is no difference between cutting

7:33and marking for vector objects other

7:35than your power settings or your speed

7:37depending on which one you’re using to

7:39control the image engraving is different

7:43image engraving is using a picture to

7:48drive the power setting beam as it

7:50travels over a shape so I’ll bring in an

7:53image that I have so this Fox something

7:59that I use to do tests with I set this

Video Transcript for LightBurn Cut Settings (Cont…)

8:02to 100 millimeters high fits here light

8:08for automatically sets this is an image

8:10cut can’t change this because it’s image

8:13engraving it’s not vector engraving

8:16image engraving is handled in very much

8:19the same way as a Spector engraving it’s

8:22affected by line interval you also get a

8:25dpi setting here in light burn and these

8:28two are just different representations

8:31of the same number it can change the

8:33interval or the DPI setting you can see

8:35the interval changes and vice versa if I

8:38change the interval dpi setting changes

8:40so we’ll start with point 1 which is

8:44what we had before here if I preview

8:47this the preview starts off as being

8:50very very dark and that’s just because

8:51it’s not easy for me to draw lines of

8:54different thicknesses in this preview if

8:56you zoom in though you can see the

8:58details start to show up so what’s

9:01happening is in the areas of brighter

9:04portions of the picture the laser is

9:06being turned off for longer periods of

9:08time then it’s turning on and that

9:10produces light areas and conversely in

9:15dark portions of the picture the laser

9:17is being turned on for longer that it’s

9:19turned off and you end up with dark

9:21pretty straightforward this is also

9:24called dithering

9:25it’s a very common technique so if you

9:28look at the nose here lots of long lines

9:31where it’s dark compared to the brighter

9:34portions of the face where it’s left off

9:37for longer periods of time

9:39changing the interval will affect the

9:43quality of the image in the same way

9:46that it does with factory grating if I

9:48change this to 0.2 that’s now 127 dots

9:52per inch or lines per inch I preview

9:55this you can see much less detail when

Video Transcript for LightBurn Cut Settings (Cont…)

10:01you zoom in here the lines are farther

10:04apart and so there’s not as much not as

10:09many opportunities to capture shading if

10:11I change this to be say 300 or even 400

10:17dpi run that again now it’s very very

10:21dark and you have to zoom in

10:22considerably more and you can see now

10:25there’s much more detail in the face

10:27very very clearly see the nostrils here

10:30for example the pupils in the eyes and

10:33so on higher dpi generally results in a

10:38better quality output image but there is

10:40a limit your laser has a beam width and

10:44going smaller than that beam width for

10:47your interval by far is not going to

10:50affect much it’s not going to get you

10:52much

10:53better output you can do it somewhat for

10:57example if my beam is 1/10 of a

11:00millimeter wide the beam has a circular

11:03shape and so it’s not a square so if I

11:08have a square like this that is 1/10 of

11:12a millimeter wide and I put another

11:14square next to it one tenth of a

11:16millimeter away you can see that they

11:19butt up nicely against each other

11:21circles don’t work that way if I take

11:24two circles that are 1/10 of a

11:25millimeter in diameter and put them next

11:27to each other you can see there’s a lot

11:28a fair bit of area here that’s not

11:31really covered by those the power of the

11:34beam is focused in the middle and it

11:37falls off towards the edges so it’s

11:39actually okay to have a bit of overlap

11:41so if you’ve got a beam that is 1/10 of

11:46a millimeter wide you can afford to

11:48overlap them a little bit and that will

11:50get you something you can also run the

11:54beam slightly out of focus that

11:55sometimes helps with grayscale engraving

11:58there are a whole bunch of tricks that

11:59you’ll read to get various results and

Video Transcript for LightBurn Cut Settings (Cont…)

12:03various improvements so on the one that

12:07affects things the most is your interval

12:10setting so play with that if I in here

12:16and they will over scan this is

12:20something else that affects both vector

12:22and image engraving it’s a useful tool

12:25with some lasers this is handled

12:28automatically at hardware with G code

12:31based lasers it’s not so let me remove

12:34the image will preview this with scan

12:39enabled if I turn on traversal moves

12:43here so you can see the laser path

12:46itself so in this case the laser is

12:49going to start here move here turnoff

12:51right there

12:52jump over to this and reverse direction

12:55and turn on pretty much at the same time

12:57and the laser doesn’t move instantly it

13:01has to speed up and slow down so when it

13:03gets to this point it’s reversing

13:05direction it’s slow

13:06speeds up with the power-on travels

13:10along this line starts to slow down

13:12again before it gets to the end here

13:14jumps down to the next line reverses

13:16direction and so on what ends up

13:19happening is in systems that don’t have

13:20very great power control if you get over

13:23burn on these edges where you’re

13:25changing directions so particularly down

13:27here where these directions changes are

13:29like 90 degrees the laser hits here past

13:32the stop dead move down start up again

13:35you’ll end up with burn on these ends

13:39the way to stop that is with the

13:41overscan setting if I turn on over

13:45scanning I have my religious that I read

13:52it does this hardware so let me okay so

13:59I basically just changed which laser I’m

Video Transcript for LightBurn Cut Settings (Cont…)

14:02using in light burns try to ignore that

14:05for a moment my read a laser does

14:08overscan in hardware it’s not a setting

14:11I’m allowed to use with that laser with

14:13a g-code laser however doesn’t do that

14:16hardware so you get a setting here

14:18called over scale if you turn this on I

14:22preview now you can see these red lines

14:26here showing the traversal modes

14:28actually shoot out past the ends of my

14:31cuts so what’s happening is light burn

14:34is telling the laser to keep going past

14:38the end of your shape and then turn

14:42around out here start going back up

14:45again ramp up to speed in this region

14:48and basically the idea is that the laser

14:51head is already up and running and

14:52moving by the time it gets back to your

14:54shape and the beam turns on and so it’s

14:57not hovering over this area for an

14:59extended period of time while speeding

15:01up with the laser on and therefore you

15:03don’t get a concentrated burn on these

15:06edges if you have a G code-based laser

15:08user over scanning for pretty much

15:10everything it for engraving at least it

15:14may

15:14big difference it really does result in

15:16much cleaner edges it also works the

15:20same when you’re doing image engraving

15:21if you have a picture you can enable

15:26over scanning for picture engraving as

15:28well and if I preview this you can see

15:31on these edges the laser is doing

15:35exactly the same thing it’s going past

15:37the last dots of the image it goes well

15:40past the end here turning changes

15:42direction out here turns around and goes

15:44back the other way over standing is a

15:47percentage of your speed

15:50it defaults to two and a half percent

15:51you can change that number if you find

15:54that that’s not enough or if it’s too

15:55much over scanning also affects how much

15:59working area you have if I park this

Video Transcript for LightBurn Cut Settings (Cont…)

16:01image right here at my origin for

16:03example in a normal laser without

16:07overscan this is okay the laser is just

16:11going to scan back and forth and stop

16:13right at the edge of this image if you

16:16have over scan enabled however what ends

16:19up happening is the laser moves past the

16:21image turns around and moves back you

16:23may bump into your limits if you use

16:27over scan really close to the edges of

16:29your frame like this so be aware of that

16:34there are also different methods to use

16:38for image and rating the one that you’ve

16:41seen so far here is called dithering

16:45after that so dither is the default

16:48option it’s generally the best general

16:52use option if I turn off traversal moves

16:57and zoom in it’s pretty obvious what

17:00digging is doing it’s just turning the

17:02laser off and on rapidly to get you

17:05shading there’s no gray scales here it’s

17:08just on and off it’s binary it’s packing

17:12dots tightly together so that if you

17:14move back far enough away from the

17:16monitor or from the resulting burn it

17:18looks like a picture

17:20this kind of dithering which is called

17:23error diffusion dithering works really

17:26well for photographs and continuous-tone

17:29pictures it does not work well for

17:33cartoon-like images so for example if I

17:37bring in this picture and use the same

17:41setting with this image you can see

17:44these tendrils strange wavy lines in the

17:49picture what’s happening is the software

17:54remembers how wrong I was basically I

17:59only have black and white on or off to

Video Transcript for LightBurn Cut Settings (Cont…)

18:02use to generate the shading in this

18:05picture it picks one that’s closest to

18:08the original color tone of the image and

18:11it remembers how wrong it was and it

18:14takes a small amount of that error and

18:16it shifts it in the directions away from

18:19that dot and so what ends up happening

18:21is these little lines here are just that

18:24error being shuffled further and further

18:25along because there’s nowhere for it to

18:27go this image has a pure white

18:29background pure white is perfect same as

18:33black and so it’s not wrong so it gets a

18:36little bit wrong at the beginning here

18:37and then it’s just perfect all the way

18:39through and so there’s nowhere for that

18:40error to go and so it just ends up

18:42dropping random little dots along the

18:44picture the way to combat this is to use

18:48I have one of the other methods of

18:50shading so there’s ordered ordered is a

18:53more regular pattern shade you can see

18:58that here this is also called halftone

19:01shading but it’s most commonly referred

19:05to as ordered dithering it’s a simple

19:08pattern that gets applied at so you can

19:09see that here this is not subject to the

19:13same kinds of problems that diffusion

19:16dithering is but it doesn’t work as well

19:18for continuous tone pictures you also

19:21have the option to do straight thread

19:23folding which is just one or the other

19:27depending on which one’s closer

19:30for one bit images just black-and-white

19:32images literally with no shading this is

19:35actually a decent option for most other

19:37things it’s terrible so it’s generally

19:39not used if you did or something outside

19:43of light burn for example if you have

19:46photograph or you have other dithering

19:48software that produces a one bit image

19:50you will probably want to use the

19:52threshold option here and match the size

19:56and dpi setting of whatever the picture

19:59is that you brought in and that will

Video Transcript for LightBurn Cut Settings (Cont…)

20:01give you the least amount of processing

20:03on that image the last option is

20:07grayscale grayscale is harder to use but

20:12ultimately gives you the best shading we

20:14look at this with threshold it’s

20:17terrible if I change this to ordered

20:21it’s a little better still not great if

20:26I change that to dithered it’s better

20:30still but it’s still not a true

20:35grayscale image if I do grayscale

20:39engraving and we tell this to shade

20:43according to power this is actually

20:47what’s going to be output to the laser

20:49you can see these lines are varying in

20:52power and that variation in power is

20:56what’s creating the shading this is the

21:00best option for photo realistic shading

21:03that you have but it’s also the hardest

21:05to work with this requires a lot of

21:08trial and error to get right because

21:09different materials burn at different

21:11rates that darken at different rates it

21:14is not simple to make this work however

21:18the results can be well worth it so you

21:20are encouraged to try it again the same

21:24other caveats apply changing the

21:27interval or the DPI setting will help

21:32over scanning also works well with

21:35grayscale you can also increase the

21:38number of passes here often grayscale

21:41engraving works best when you

21:43slow and with low-power so setting for

21:47example of 70 millimeters a second with

21:50an overall power of 10 or 11% maybe and

21:54then do more than one pass and each

21:56subsequent pass will get a little bit

21:57darker again trial and error is key here

Video Transcript for LightBurn Cut Settings (Cont…)

22:02with grayscale grayscale is a pain there

22:05are other options as well with an image

22:09engraving you can change the scan angle

22:12so you can see I’m just changing a scan

22:15pattern here by moving the angle number

22:17this will allow you to scan vertically a

22:20scan at an angle some people find that

22:23with diode lasers for example scanning

22:25at an angle helps eliminate or reduce

22:28the effect of the oval shape of the beam

22:34your mileage may vary play with

22:36different things with vector engraving

22:39you also have a mode called crosshatch

22:43which I really like crosshatch basically

22:46does a double scan so it goes one way

22:49then goes the other way and you can do

22:51the same scan angle changes with that

22:53one

22:54and crop size can actually give you some

22:57cool results if you use a large interval

23:00so I set this to one millimeter and

23:03preview this the crosshatch pattern is

23:06kind of an interesting fill it’s a way

23:11of getting a filled shape or something

23:14that looks filled but isn’t necessarily

23:16going to cost you nearly as much time as

23:19a full vector over rave its stylized you

23:27can set that fairly high you can also

23:30use what’s called scan plus cut this

23:33basically does a scan over a shape with

23:37crosshatch or without and then runs

23:40around the outline with the settings

23:42that you see below so you get both scan

23:45speed and power settings and you get cut

23:50speed and power settings the same way

23:52you do with a regular cut this if you

23:55watch the preview

23:57does the normal raster scan of a shape

23:59and then runs the outline so it’s useful

Video Transcript for LightBurn Cut Settings (Cont…)

24:03for things where you want to do engrave

24:07and then highlight the edge or extend to

24:09accent the edge and you don’t have to

24:12use two separate cutting paths to do it

24:14it’s a useful trick