Session 23 – 3D Engraving With A CO2 Laser

The Concise RDWorks Learning Lab Series

Welcome to Module 3 of the new Concise RDWorks Learning Lab Series with Russ Sadler. Module 3 will build on the information learned in the previous modules and will be targeted on the differing types of laser engraving methods and the techniques needed to consistently achieve great engraving results. So let’s learn how to do 3D Engraving with a CO2 laser!

In this Session, Russ discuss the “black art” of 3D engraving that your laser machine can carry out on cuttable materials such as woods and plastics. While it’s not an easy topic, once you have set up the foundation work for your particular machine and graphics software, you will be well on the way to producing incredible 3D images.

Release Date: 17th December 2021

Over the last 6 years, Russ has built up a formidable YouTube following for his RDWorks Learning Lab series which currently has over 200 videos.

The original RDWorks Learning Lab series on his “Sarbar Multimedia” YouTube Channel, follows Russ as he tries to make sense of his new Chinese laser machine and to sort out the truths, half truths and outright misleading information that is available on the web.

Six years later with over 3 million YouTube Views under his belt, Russ has become the go to resource for everything related to the Chinese CO2 laser machine user or wannabe user.

how to do 3D Engraving with a CO2 laser
3D laser engraved acrylic

In this new series, Russ has condensed his knowledge and experience of the last 6 years to provide valuable information and insights into the purchasing, understanding, use, repair and maintenance of the Chinese CO2 laser machines and their key component parts.

Previous VideoNext VideoSeries Menu

Watch Session 23 – 3D Engraving With A CO2 Laser, through the Panopto Viewer;

Watch this video through the Panopto Viewer (free sign-up required for full functionality) for a more interactive viewing experience. The viewer will allow you to:

  • Change the Captions to show translated subtitles if English is not your first language.
    • Currently available languages include: Chinese (Simplified), Danish, Finnish, French, German, Hungarian, Italian, Japanese, Korean, Norwegian, Polish, Portuguese, Spanish, Swedish and Thai . These are Google translations, so if you spot any errors, please let us know.
  • You can search the video for specific keywords and jump to the relevant section.
    • This can work both within an individual video, across all videos and across all translated languages.
  • Post public comments on the video as well as private comments to the moderators.
  • Add your own notes, synchronised to what you are watching
  • Add bookmarks to remind you of important items.

Podcast Download

You can download the audio file for this video here, just click on the three dots to the right of the player:

Podcast Session 23 – 3D Engraving

Video Resource Files for 3D Engraving With A CO2 Laser

There are no resource files associated with this video.

There are no external resource links associated with this video.

Transcript for 3D Engraving With A CO2 Laser

Click the “Show More” button to reveal the transcript, and use your browsers Find function to search for specific sections of interest.

Transcript for 3D Engraving With A CO2 Laser

1
00:00:06,150 –> 00:00:15,180
The Concise RDWorks Learning Lab with the Russ Sadler. Session 23: 3D Engraving.

2
00:00:15,180 –> 00:00:23,310
Now, these might be cheap Chinese machines that you have, but there are some amazing things that it can do.

3
00:00:23,310 –> 00:00:29,640
One of the amazing things we’re going to tackle today is called 3D engraving. Look, put your hand up to your face,

4
00:00:29,640 –> 00:00:39,150
touch your nose, feel your eyes, it’s 3D. That’s what we’re going to get in a piece of soft organic material like wood, acrylic,

5
00:00:39,150 –> 00:00:45,120
maybe MDF, anything that will cut, you will be able to produce a 3D image on.

6
00:00:45,120 –> 00:00:51,330
You won’t be able to do it on things like slate, stone, glass because you can’t cut those.

7
00:00:51,330 –> 00:00:55,800
You can only scratch the surface. This is a very complex subject.

8
00:00:55,800 –> 00:01:00,900
We’re going to bring many of the things that we’ve already talked about into play today,

9
00:01:00,900 –> 00:01:11,640
and I will reinforce some of the things that we’ve already learnt. Go to Google, as I’ve got shown on the screen here, and just type in 3D bitmap images.

10
00:01:11,640 –> 00:01:20,470
Now, these weird looking pictures. It’s difficult to describe some of them, waxy, ghostly?

11
00:01:20,470 –> 00:01:30,490
They’re a bit unreal, this one here has got lots of contrast in it and is ideal for me describing exactly how things work today.

12
00:01:30,490 –> 00:01:34,090
So we’re going to take this picture and I’m going to open it up in Photoshop.

13
00:01:34,090 –> 00:01:41,770
Let’s just take a look at this picture and we’ll see that it is only 72 pixels per inch.

14
00:01:41,770 –> 00:01:50,470
Now, 72 pixels per inches, is quite a coarse picture, but remember the relationship between pixels, size,

15
00:01:50,470 –> 00:02:02,050
the detail that you want in a picture. For example, if you’ve got somebody’s eye you can’t clearly define in a picture, somebody’s eye with only two pixels.

Transcript for 3D Engraving With A CO2 Laser (Cont…)

16
00:02:02,050 –> 00:02:10,270
You might need 200 or 300 pixels to clearly show the detail in somebody’s eye.

17
00:02:10,270 –> 00:02:15,790
So don’t forget some of the lessons that we’ve already learned in previous sessions.

18
00:02:15,790 –> 00:02:25,030
I’m going to change this from 72 pixels per inch, which is the standard resolution that most images are transmitted over big WWW with,

19
00:02:25,030 –> 00:02:29,890
and I can convert that to 127 pixels per each.

20
00:02:29,890 –> 00:02:36,040
Now that I happen to know is a pixel size of 0.2 millimetres.

21
00:02:36,040 –> 00:02:41,770
And I’ll tell you all about that number when we come to set up the parameters for engraving this picture.

22
00:02:41,770 –> 00:02:48,130
Now, when you look at that picture, your brain intuitively can see that as a 3D image.

23
00:02:48,130 –> 00:02:56,500
The clues in that picture somehow tell you that it is not a flat 2D drawing, even though it is.

24
00:02:56,500 –> 00:03:03,070
How does that happen? Well, this will help to explain how your brain deals with that problem.

25
00:03:03,070 –> 00:03:06,310
What we have here is something called a topographical map.

26
00:03:06,310 –> 00:03:12,550
Now the top there you see an amazing picture of my wonderful desert island home.

27
00:03:12,550 –> 00:03:19,210
I’ve got a big villa right on the top of that mountain, fantastic views. No roads,

28
00:03:19,210 –> 00:03:23,140
so I can’t drive my car there. But hey, we can all dream.

29
00:03:23,140 –> 00:03:26,290
The guy that did this map, I think, made a little bit of a mistake.

30
00:03:26,290 –> 00:03:34,210
If we look at the bottom there, it says eleven hundred and then go twelve hundred, thirteen hundred, fourteen and those are rubbish numbers.

31
00:03:34,210 –> 00:03:40,480
Let’s just assume that that bottom line there should say one hundred and then 200, 300, 400.

32
00:03:40,480 –> 00:03:45,700
Now those are meters above sea level, which is the black stuff.

33
00:03:45,700 –> 00:03:56,650
If I was to do slices through my island and that’s what the slices would look like if they were laid down onto a 2D image.

34
00:03:56,650 –> 00:03:58,210
Put it another way.

Transcript for 3D Engraving With A CO2 Laser (Cont…)

35
00:03:58,210 –> 00:04:09,010
If I had a path all the way round the island at 100 meters above sea level, the line which says one hundred is the shape of the path.

36
00:04:09,010 –> 00:04:17,690
What we’ve done is to convert a 3D image into a 2D mapping, and that’s what we see here.

37
00:04:17,690 –> 00:04:28,030
The black is the sea level, the background and the white here, is the tops of the mountains, the foreground.

38
00:04:28,030 –> 00:04:33,220
And so consequently, what we see in that picture appears to be 3D.

39
00:04:33,220 –> 00:04:38,080
Even though it’s not and that’s how our brain interprets it sees the shadows,

40
00:04:38,080 –> 00:04:46,420
the shades of grey, and it puts them into some sort of perspective view that isn’t really there.

41
00:04:46,420 –> 00:04:53,500
As I said, our brain is stupid in some ways, and incredibly clever and others. You can easily fool it.

42
00:04:53,500 –> 00:04:59,060
And here we are fooling your brain into creating a 3D image from a 2D picture.

43
00:04:59,060 –> 00:05:07,180
It is this basis of shades of grey. And remember the grayscale that we spoke about in the previous session?

44
00:05:07,180 –> 00:05:15,610
Those shades of grey are going to be used now to create a 3D image with our laser machine.

45
00:05:15,610 –> 00:05:20,410
So let’s move on to how that actually happens. And now that I’ve brought it onto full screen.

46
00:05:20,410 –> 00:05:27,360
If you take a look where my cursor is, you can see the pixels around the edge of this image.

47
00:05:27,360 –> 00:05:36,940
Let me zoom in as far as I can. Remember, those squares are 0.2mm and they are pixels.

48
00:05:36,940 –> 00:05:43,900
So every pixel on that screen has got its own coordinates. In addition to those coordinates,

49
00:05:43,900 –> 00:05:49,420
there’s another piece of information that’s stored and that is the colour of the pixel.

50
00:05:49,420 –> 00:05:54,370
Now, if we take a look around that screen, you’ll see that pixels go from black.

51
00:05:54,370 –> 00:06:02,500
If you remember the grayscale code, black equals zero to white and white equals 255.

Transcript for 3D Engraving With A CO2 Laser (Cont…)

52
00:06:02,500 –> 00:06:10,480
Every single pixel and it’s information, it’s colour information is stored in the controller, the next bit almost incomprehensible.

53
00:06:10,480 –> 00:06:15,310
You start scanning across and as it scans across like this one pixel at a time,

54
00:06:15,310 –> 00:06:22,120
it says, okay, that colour there is, I don’t know, maybe one five five 1/2 power.

55
00:06:22,120 –> 00:06:27,530
So turn the laser beam on to half power and do a burn.

56
00:06:27,530 –> 00:06:35,360
And then it moves on to the next pixel and says, well, this is a bit lighter, we’ll turn the power down a little bit, we won’t burn quite as deep.

57
00:06:35,360 –> 00:06:43,020
Now we turn the power down again and again and again. And now we start turning the power up so that it’s heavy and black, OK?

58
00:06:43,020 –> 00:06:46,970
And then we get to hear where it’s nearly white. That will turn the power off.

59
00:06:46,970 –> 00:06:49,850
We don’t want any burning at this point because it’s white.

60
00:06:49,850 –> 00:06:57,770
It does that all the way across here for every single pixel at the scan speed of maybe two or three hundred millimetres a second.

61
00:06:57,770 –> 00:07:00,620
Now, that sounds absolutely unbelievable,

62
00:07:00,620 –> 00:07:10,190
but it’s not that unbelievable when you think that the electronics is capable of responding at something like nanosecond speeds.

63
00:07:10,190 –> 00:07:16,010
Once the change of current has been decided in nanoseconds, it takes even less than that,

64
00:07:16,010 –> 00:07:22,130
almost instantaneous that the change of current to occur and the Watts output to happen.

65
00:07:22,130 –> 00:07:29,390
So it’s possible to scan very fast and get rapid, instantaneous changes of current or burn.

66
00:07:29,390 –> 00:07:39,670
There are two other problems with this process. The first one is this line here is 0.2mm wide.

67
00:07:39,670 –> 00:07:49,090
It’s scanning across one line of pixels. After it’s done its scan, it has to move down exactly one pixel.

68
00:07:49,090 –> 00:07:57,790
To the next line of pixels, so that it can come back and and do the burning on the next line of pixels, and so it goes.

Transcript for 3D Engraving With A CO2 Laser (Cont…)

69
00:07:57,790 –> 00:08:04,150
So we must ensure that when we set the parameters for this image,

70
00:08:04,150 –> 00:08:14,020
we make sure that the scanline interval or the line interval matches perfectly the resolution of the picture,

71
00:08:14,020 –> 00:08:20,690
because if we don’t, we should get a distorted image. OK, now there’s another problem.

72
00:08:20,690 –> 00:08:27,070
We’re making the assumption here that we’ve got a 0.2mm wide burn line.

73
00:08:27,070 –> 00:08:31,240
Maybe your machine can’t produce a 0.2mm burn line.

74
00:08:31,240 –> 00:08:36,100
Maybe it’s only capable of producing a 0.4mm burn line.

75
00:08:36,100 –> 00:08:45,310
In which case, you will find that you’ve got half a pixel above and half a pixel below the scanline, which is being burned.

76
00:08:45,310 –> 00:08:52,750
So when I move down a scanline, I’ve already got half a pixel burnt on that next scanline.

77
00:08:52,750 –> 00:08:57,880
And when I move down again, I should leave half a pixel burnt behind.

78
00:08:57,880 –> 00:09:03,760
So the pixel trailing behind the burn line will have a double burn,

79
00:09:03,760 –> 00:09:11,360
half a pixel from leading and half a pixel from trailing. extra burn so that pixel will get double burnt.

80
00:09:11,360 –> 00:09:16,760
And that’s going to cause a distortion in your image, it’s going to make it black, it’s going to make it deeper.

81
00:09:16,760 –> 00:09:25,960
So you must really make sure that you understand what the width of your burn line is before you attempt to do any of this sort of work.

82
00:09:25,960 –> 00:09:32,080
Now, if you remember, the width of the burn line changes rapidly with speed.

83
00:09:32,080 –> 00:09:36,970
So you need to fix the speed and determine what the width of your burn line is.

84
00:09:36,970 –> 00:09:44,970
Sadly, there’s another little problem that comes in. Although the major control of line width is speed.

85
00:09:44,970 –> 00:09:55,760
As you change the power, so the burn width changes as well. A black pixel is going to create a wider burn line than a white pixel.

86
00:09:55,760 –> 00:10:00,230
No way around that, I’m afraid you’re stuck with that one.

Transcript for 3D Engraving With A CO2 Laser (Cont…)

87
00:10:00,230 –> 00:10:09,050
OK, so I’ve imported my bitmap into the free software that comes with the Ruida controller, a program called RDWorks.

88
00:10:09,050 –> 00:10:13,040
And I shall be using this program throughout this series.

89
00:10:13,040 –> 00:10:17,930
And there are other programs that you can buy, one in particular called Lightburn,

90
00:10:17,930 –> 00:10:22,640
which is in some ways a significantly better program than RDWorks.

91
00:10:22,640 –> 00:10:27,350
But you won’t need it at the moment, when you get seriously involved with this,

92
00:10:27,350 –> 00:10:36,710
you might want to go and really investigate Lightburn, because it is an amazing piece of software, but it only does the same as this.

93
00:10:36,710 –> 00:10:43,700
Plus hundreds of extra things with knobs on. We’re going to stick to the basics and we’re Going to use RDWorks.

94
00:10:43,700 –> 00:10:50,150
Now, we’ve imported this file. If you look at the top right hand corner, you’ll notice we’ve got bitmap BMP.

95
00:10:50,150 –> 00:10:59,000
If I click on that, you’ll find that this piece of software has intelligently decided that this is a bitmap and not a vector file.

96
00:10:59,000 –> 00:11:03,650
You can’t cut or draw lines with it. You can only scan it.

97
00:11:03,650 –> 00:11:13,280
When we come down to the parameter box here and look at the processing mode, we’ve got a dropdown box which would normally give us lots of options.

98
00:11:13,280 –> 00:11:17,990
Not in this case. It says you can only scan this job.

99
00:11:17,990 –> 00:11:24,920
We’re going to play with speed when we get onto the machine itself. But for the moment, I’m just going to set that to two hundred.

100
00:11:24,920 –> 00:11:31,640
Now, there are other things that we’re going to talk about in here in a moment as well. But before we do that, I’m just going to close this box again,

101
00:11:31,640 –> 00:11:37,340
OK. Click on the picture and come up here to handle and in handle,

102
00:11:37,340 –> 00:11:45,260
we’ve got bitmap handle. OK, now we get this silly box up here, which says “Do you want to process the picture?”

103
00:11:45,260 –> 00:11:50,510
Basically, that means do you want to do any Photoshop work on it? You adjust the lightness, the colour, whatever.

104
00:11:50,510 –> 00:11:53,720
But just say no, because we’re not interested in that at the moment.

105
00:11:53,720 –> 00:12:01,610
What we’re interested in, is the simple specification to make sure that what we’ve got coming in here, matches what we thought we got coming in.

Transcript for 3D Engraving With A CO2 Laser (Cont…)

106
00:12:01,610 –> 00:12:08,300
And if we take a look at the top here, we shall see that we’ve got a resolution of 127 pixels per inch.

107
00:12:08,300 –> 00:12:11,600
We’re happy. Now, it’s important that we check that.

108
00:12:11,600 –> 00:12:18,890
Now, remember a few minutes ago, I talked about the line interval to make sure that it matches the resolution of the picture.

109
00:12:18,890 –> 00:12:25,850
This is a very important piece of information that you really ought to write down somewhere, that the line interval is in millimetres,

110
00:12:25,850 –> 00:12:30,410
but the resolution of the picture is in pixels per inch.

111
00:12:30,410 –> 00:12:40,730
PPI. Just remember this one number here, twenty five point four. Now, twenty five point four is the number of millimetres in an inch.

112
00:12:40,730 –> 00:12:47,960
So effectively what we’ve got here is one inch in millimetres divided by pixels per inch,

113
00:12:47,960 –> 00:12:54,350
twenty five point four divided by 127 seven pixels per inch.

114
00:12:54,350 –> 00:12:59,960
Do that calculation and the answer will come out to 0.2mm and

115
00:12:59,960 –> 00:13:06,320
it’s 0.2mm that you’re going to have to put into here.

116
00:13:06,320 –> 00:13:10,190
Now, we’ve talked about this before, scan mode. You’re going to leave that set to X-swing.

117
00:13:10,190 –> 00:13:16,020
And basically what that means is that you will be able to scan the picture across,

118
00:13:16,020 –> 00:13:26,290
from left to right, and it will burn a line of pixels. It will then drop down one line interval and scan back the other direction.

119
00:13:26,290 –> 00:13:33,030
Now very conveniently, I’ve set the speed here to 200 millimetres a second.

120
00:13:33,030 –> 00:13:37,860
And I’ll go back and I’ll just remind you that we did set,

121
00:13:37,860 –> 00:13:49,390
the reverse scanning interval, to match two hundred millimetres a second and I said to you, if you choose any other scanning speed,

122
00:13:49,390 –> 00:13:55,600
you will need to go back and recalibrate for the speed that you are using.

123
00:13:55,600 –> 00:14:04,000
Remember how I said to you, the machine has the ability to change its power to match the colour of the pixels.

Transcript for 3D Engraving With A CO2 Laser (Cont…)

124
00:14:04,000 –> 00:14:09,850
This is how we make it perform that trick. We tick the output direct box.

125
00:14:09,850 –> 00:14:16,290
Now, we’re going to come onto a rather difficult and complex subject. Now, in the previous line drawing section.

126
00:14:16,290 –> 00:14:28,150
We used minimum power. To limit the power against velocity as we drove the line into a sharp corner.

127
00:14:28,150 –> 00:14:37,400
To stop it from over burning in the corners. Now I’ve set Max and Min power to 05 and 80 per cent for this particular application.

128
00:14:37,400 –> 00:14:43,650
But because I have got this output direct box up here ticked.

129
00:14:43,650 –> 00:14:49,020
The way in which it operated previously in line drawing is no longer valid.

130
00:14:49,020 –> 00:14:55,530
These two numbers have got completely different meanings for 3D engraving.

131
00:14:55,530 –> 00:15:03,900
What I’d like you to imagine is, that, that box there is white and that box there, Max, is black.

132
00:15:03,900 –> 00:15:08,100
When we scan across here, we come across a white pixel.

133
00:15:08,100 –> 00:15:14,800
The controller will send a five percent power requirement to the tube.

134
00:15:14,800 –> 00:15:20,650
And it will draw a very light pixel, and when it comes across a black pixel,

135
00:15:20,650 –> 00:15:25,150
it says, OK, wind the power up to 80 percent because I want a lot of burning.

136
00:15:25,150 –> 00:15:31,480
The grayscale code is zero to two five five, two hundred fifty six steps.

137
00:15:31,480 –> 00:15:35,800
This five represents white, which is two five five.

138
00:15:35,800 –> 00:15:40,120
And this 80 represents black, which is zero.

139
00:15:40,120 –> 00:15:54,080
So between eighty and five. The controller is dividing this interval into two hundred and fifty six discrete steps of power.

140
00:15:54,080 –> 00:16:01,970
If I change this down to 60 percent, it’ll change that range to two hundred and fifty six steps of power.

Transcript for 3D Engraving With A CO2 Laser (Cont…)

141
00:16:01,970 –> 00:16:06,230
That’s the way in which the machine uses these two numbers.

142
00:16:06,230 –> 00:16:15,800
If you just use the Max / Min, as I’ve specified, you’ll be absolutely amazed at the 3D ness of the image that you can produce.

143
00:16:15,800 –> 00:16:24,830
But I’ll ask you to go and look at my other channel, RDWorks learning Lab, number 126 &127,

144
00:16:24,830 –> 00:16:30,680
which deal with this subject in a slightly more analytical way. And one of the things

145
00:16:30,680 –> 00:16:38,240
that you’ll find out is this; the output from the laser in terms of Watts is not linear.

146
00:16:38,240 –> 00:16:48,650
So when you specify that you’d like five percent power and here we are down at the bottom of this graph here where my cursor is, at five per cent power.

147
00:16:48,650 –> 00:16:53,210
We’re not probably going to get anything out of the tube at all. When we get to 80 percent,

148
00:16:53,210 –> 00:17:00,220
you can see there is not a straight line between that point there where my cursor is,

149
00:17:00,220 –> 00:17:05,410
and zero. So we’ve got a very non-linear type of burning

150
00:17:05,410 –> 00:17:14,050
that’s going to take place. Because the Watts output is not related to the percent power, it’s not linear.

151
00:17:14,050 –> 00:17:19,120
You’re going to get a distorted image, unless you do something like that.

152
00:17:19,120 –> 00:17:33,790
And then what we do, we completely rework the system to find out how much distortion is required to keep the power at a constant level.

153
00:17:33,790 –> 00:17:38,830
Now, we can’t change the power of the machine. Within Photoshop,

154
00:17:38,830 –> 00:17:46,720
we have the ability in something called Curve’s to reset the relationship for these colours, if

155
00:17:46,720 –> 00:17:52,960
the mid-greys are going to over burn, because we’ve got a lot more power in the mid-greys.

156
00:17:52,960 –> 00:18:00,220
What we can do, we can make the mid-greys slightly lighter, so that they do not burn as much.

Transcript for 3D Engraving With A CO2 Laser (Cont…)

157
00:18:00,220 –> 00:18:09,760
Taking the data that I’ve just constructed in that graph, as you can see, look, I have input eight percent and I’m expecting five percent output.

158
00:18:09,760 –> 00:18:14,870
And what that will do eventually, it’ll produce a distorted image.

159
00:18:14,870 –> 00:18:25,450
So I’m going to step back and look at the way in which the white changes when I remove this colour offset.

160
00:18:25,450 –> 00:18:32,090
Do you see what I mean? What I’ve done, I have artificially lightened parts of the picture.

161
00:18:32,090 –> 00:18:41,990
So that it doesn’t burn as deeply and this offsets the non-linear power that I’m getting from the tube.

162
00:18:41,990 –> 00:18:45,440
This is why I’m saying, I’m not going to touch this in this video.

163
00:18:45,440 –> 00:18:53,090
You need to go and look at RDWorks Learning Lab 126 & 127 for a lot more data on this subject.

164
00:18:53,090 –> 00:18:59,630
Now we’ve got yet another and I hope, final level of complexity that you need to understand about 3D

165
00:18:59,630 –> 00:19:06,790
engraving. And that’s the way in which your tube works, how it switches on and off.

166
00:19:06,790 –> 00:19:13,330
As I mentioned to you when we talked about the power supply and I talked about it a little bit earlier in this session.

167
00:19:13,330 –> 00:19:19,300
Switching the tube on could take a millisecond. Once the tube is switched on,

168
00:19:19,300 –> 00:19:27,280
the control of the electronics, which is making the current flow, is happening at a billionth of a second speeds.

169
00:19:27,280 –> 00:19:33,970
So switching between different pixels to different colours is not a problem for the electronics.

170
00:19:33,970 –> 00:19:39,550
It’s not a problem either for the light speed changes that happen within the tube.

171
00:19:39,550 –> 00:19:48,790
So go back to the beginning of that sentence and let’s just restate it takes maybe up to a millisecond to switch the tube on.

172
00:19:48,790 –> 00:19:53,920
We can’t have a millisecond switch on, after we’ve reached a white pixel.

173
00:19:53,920 –> 00:20:00,520
By that time, we may well have missed another eight or 10 or 15 or 20 pixels.

Transcript for 3D Engraving With A CO2 Laser (Cont…)

174
00:20:00,520 –> 00:20:06,620
It’s taking that long to switch the tube back on after it has switched off.

175
00:20:06,620 –> 00:20:14,750
And it switches off when it sees white two five five, if we take a look at this levels picture,

176
00:20:14,750 –> 00:20:20,710
you’ll see that it runs output levels zero to two five five.

177
00:20:20,710 –> 00:20:27,220
OK, so there’s something here which is black, lots of it, as you can see,

178
00:20:27,220 –> 00:20:35,920
and quite a lot of fairly light and a little bit of white right up at this top end here. At certain points in here,

179
00:20:35,920 –> 00:20:40,720
white is going to switch the tube off and causes a problem.

180
00:20:40,720 –> 00:20:52,630
But what we can do, we can again distort this picture very slightly, very slightly by changing this number from, say, 255 output levels,

181
00:20:52,630 –> 00:21:01,310
To 250 and 250 is not white. 250 is very, very nearly white.

182
00:21:01,310 –> 00:21:11,630
So much so that you won’t notice the difference, but what it does mean is, the tube will never get an instruction to turn off.

183
00:21:11,630 –> 00:21:14,450
So that’s our goal by setting 250.

184
00:21:14,450 –> 00:21:23,690
We do not want the tube to switch off because as soon as it switches off, it loses its performance, its speed just for the hell of it.

185
00:21:23,690 –> 00:21:27,950
I’m going to set the numbers to 10 and 50.

186
00:21:27,950 –> 00:21:32,840
Any two numbers will work. It’s just that they might not be the best numbers.

187
00:21:32,840 –> 00:21:39,140
So we’ve basically now got our parameters set. So we’ve got a range of burning for our grayscale.

188
00:21:39,140 –> 00:21:48,200
We’ve got speed, which is constant. We’ve got a step which matches the bitmap resolution and we’ve ticked our output

189
00:21:48,200 –> 00:21:55,040
direct box. So we’ve now spoken about all the principles and problems associated with 3D engraving.

Transcript for 3D Engraving With A CO2 Laser (Cont…)

190
00:21:55,040 –> 00:22:06,710
I’m going to give you a quick demonstration on this material, which is Bamboo. One of the worst possible materials you could ever use for 3D engraving.

191
00:22:06,710 –> 00:22:16,740
I did say that all these colored strips in this material represent a different type of wood. The molecular structure

192
00:22:16,740 –> 00:22:24,730
of all these strips is completely different, which means they will have completely different cutting characteristics.

193
00:22:24,730 –> 00:22:32,450
Now I’ve change the parameters away from what we spoke about in the office very slightly, five millimetres, a second minimum.

194
00:22:32,450 –> 00:22:38,330
So we get virtually zero cut because this beam will hardly fire at five millimetres a second.

195
00:22:38,330 –> 00:22:41,270
But remember, it’s not the firing of the beam that causes

196
00:22:41,270 –> 00:22:48,200
the problem. It’s the switching on and off, the switching on and off of the beam is controlled by white.

197
00:22:48,200 –> 00:22:56,360
And there is no white in this picture because we’ve changed away all the white to nearly white at colour 250.

198
00:22:56,360 –> 00:23:01,670
So I’m going to do two things. Remember the lessons that we learned from previous engraving?

199
00:23:01,670 –> 00:23:05,450
We don’t want to cut. We want to mark the surface.

200
00:23:05,450 –> 00:23:09,740
We want a little bit of depth. But we don’t want serious burning. All right.

201
00:23:09,740 –> 00:23:14,270
So I’m going to set this up for 25mm.

202
00:23:14,270 –> 00:23:20,420
Remember the manufacturers gap here, specification that we’ve been using is 20mm.

203
00:23:20,420 –> 00:23:29,300
I’ve raised the focus up by five millimetres. We’ve got an extra window here which allows me to select the number of passes.

204
00:23:29,300 –> 00:23:42,500
This is not a one hit job. I suspect it’s going to take at least six passes probably to do, to get some 3D ness into this, some moderate 3D ness into this.

205
00:23:42,500 –> 00:23:51,980
It might require eight or even ten, but we’ll carry on with six. 5.0 and 95, 0.2mm increment.

206
00:23:51,980 –> 00:24:00,230
First of all, I’ve got my engraving nozzle in here, so I’ve got plenty of gap between the work to allow the smoke to come upwards.

Transcript for 3D Engraving With A CO2 Laser (Cont…)

207
00:24:00,230 –> 00:24:05,960
And I’ve got just a small amount of, hmm too much,

208
00:24:05,960 –> 00:24:09,800
just a small amount of air assist on there to protect the lens, because I want

209
00:24:09,800 –> 00:24:13,460
the smoke to come up and be drawn away before it gets blown down onto the job.

210
00:24:13,460 –> 00:24:18,630
Bamboo material is very sticky with its debris, very sticky.

211
00:24:18,630 –> 00:24:27,410
OK, now I’m going to put the extraction on. What we really want to see, is cutting without burning. I would estimate

212
00:24:27,410 –> 00:24:32,960
we’ve got probably half to three quarters of a mill cut going into that job.

213
00:24:32,960 –> 00:24:43,970
So six cuts will get us to four millimetres. There’s our 3D engraving. Not bad,

214
00:24:43,970 –> 00:24:52,320
as you can see. Let’s take a little bit of a closer look and you’ll see that,

215
00:24:52,320 –> 00:25:02,800
just here. This black wood, that all the joints look, can you see all these joints? They just haven’t machined away.

216
00:25:02,800 –> 00:25:13,850
That’s the glue and this dark wood here. Has machined away a lot more than this wood. This would here is quite hard.

217
00:25:13,850 –> 00:25:20,270
The darker the wood, the more it’s machined away. It’s a pretty abysmal wood for this sort of work. You can see the 3D

218
00:25:20,270 –> 00:25:23,810
ness, it’s worked perfectly well. Let’s try another wood. Now here

219
00:25:23,810 –> 00:25:27,620
I’ve got a piece of Poplar plywood. We’ll use the same settings.

220
00:25:27,620 –> 00:25:37,820
But before we use the settings who just test to make sure that we’re not getting too much burn, we want to remove material without burning.

221
00:25:37,820 –> 00:25:44,540
So sentenced to 25 mm. We’ll go over to one corner squares a softer wood.

222
00:25:44,540 –> 00:25:50,070
I’m going to set the parameters this time to 90 percent power and 400 millimetres a second.

223
00:25:50,070 –> 00:26:01,810
Again, we’ve got 0.2mm because remember we’re set to 127 ppi.

Transcript for 3D Engraving With A CO2 Laser (Cont…)

224
00:26:01,810 –> 00:26:17,920
That’s not bad, we’ve removed about a millimetre in one pass, six passes is going to take us about six millimetres deep. That’s a

225
00:26:17,920 –> 00:26:26,100
more even 3D replication. We’ll try it on one more wood, which is a uniform wood, but it has got a grain in it.

226
00:26:26,100 –> 00:26:34,300
And we’ll see the effect that, that has on a slightly harder wood than this. I’m led to believe that this is a piece of maple.

227
00:26:34,300 –> 00:26:43,400
We’ll try the same sort of settings again, 25mm gap, so we’re 5mm above the focal point.

228
00:26:43,400 –> 00:26:49,060
Four hundred millimeters a second. Ninety five per cent power.

229
00:26:49,060 –> 00:26:55,890
Oh, that’s not bad at all. We’ll drop down to three hundred maybe and see if we get a little bit more depth without changing the colour. You can see

230
00:26:55,890 –> 00:27:04,640
it’s still not badly burnt. It’s a little bit darker, but that’s not bad at all.

231
00:27:04,640 –> 00:27:09,170
I think as you see this go on, you’ll see that the grain that’s in this Maple,

232
00:27:09,170 –> 00:27:16,100
will stand out in the same way that the glue lines stood out in the bamboo. Now,

233
00:27:16,100 –> 00:27:23,750
there is no point in me going on with that because, look, you can clearly see how the grain is doing exactly as I said it would.

234
00:27:23,750 –> 00:27:27,710
So you’ve got to choose the right material to do this job with.

235
00:27:27,710 –> 00:27:39,240
This is a piece of acrylic. And I purposely left the film on the surface so that you can see those areas which are not being engraved.

236
00:27:39,240 –> 00:27:49,400
I suspect after several passes, most of that white will have disappeared. So in the background there you can see the beam, the pink

237
00:27:49,400 –> 00:27:53,450
beam and you’ll see it switching on and off just at the end of the stroke.

238
00:27:53,450 –> 00:27:58,390
And now it’s starting to run across the shape.

239
00:27:58,390 –> 00:28:05,060
And as it runs across the shape, you can see the intensity of the beam changing rapidly as it’s trying to keep,

Transcript for 3D Engraving With A CO2 Laser (Cont…)

240
00:28:05,060 –> 00:28:09,650
as it’s trying to change power as it runs across every single pixel.

241
00:28:09,650 –> 00:28:15,370
For this last cut, what I’m going to do.

242
00:28:15,370 –> 00:28:27,040
I’m going to take the take the beam up by at least 10 mill, like that, out of focus and I’ve also dropped the power (SPEED) to 200 millimetres a second.

243
00:28:27,040 –> 00:28:30,700
So it’s out of focus. It’s adding more heat slowly.

244
00:28:30,700 –> 00:28:40,570
I’m trying to exploit one of the properties of acrylic, and that is that it has a melt phase at one hundred and sixty degrees C, it turns to liquid.

245
00:28:40,570 –> 00:28:46,670
So what I’m trying to do is just heat and melt the surface of the material rather than vaporize it.

246
00:28:46,670 –> 00:28:51,460
I’m attempting to put a polish on the job for the final pass.

247
00:28:51,460 –> 00:28:59,950
Obviously, acrylic is a nice uniform material that’s absolutely ideal for doing this sort of 3D work.

248
00:28:59,950 –> 00:29:04,060
Well, here we are at the end of a very, very complex subject,

249
00:29:04,060 –> 00:29:13,900
which I hope, we’ve managed to cram into just over half an hour with the aid of additional learning from my RDWorks Learning Labs.

250
00:29:13,900 –> 00:29:24,090
You’ve been through the problems with the materials now. I’ve got here the nozzle, it’s nicely caked with all sorts of stuff.

251
00:29:24,090 –> 00:29:30,460
The fumes that have shot up. You’ll need to clean that from time to time with acetone. Look,

252
00:29:30,460 –> 00:29:39,700
we’ve only had a very small amount of air, passing through here all the time and assure you that Lens is as clean now as it was when it started.

253
00:29:39,700 –> 00:29:51,550
It doesn’t require too much airflow to keep that lens clean. Even though there’s a small amount of debris that’s gone up inside the nozzle there.

254
00:29:51,550 –> 00:30:02,282
It hasn’t gone up as far as the lens and caked the lens.

Transcript for 3D Engraving With A CO2 Laser

Disclaimer

Last updated August 26, 2021

WEBSITE DISCLAIMER

The information provided by n-Deavor Limited, trading as Laseruser.com (“we,” “us” , or “our”) on (the “Site”) is for general informational purposes only. All information on the Site is provided in good faith, however we make no representation or warranty of any kind, express or implied, regarding the accuracy, adequacy, validity, reliability, availability or completeness of any information on the Site.

UNDER NO CIRCUMSTANCE SHALL WE HAVE ANY LIABILITY TO YOU FOR ANY LOSS OR DAMAGE OF ANY KIND INCURRED AS A RESULT OF THE USE OF THE SITE OR RELIANCE ON ANY INFORMATION PROVIDED ON
THE SITE. YOUR USE OF THE SITE AND YOUR RELIANCE ON ANY INFORMATION ON THE SITE IS SOLELY AT YOUR OWN RISK.

The Site may contain (or you may be sent through the Site) links to other websites or content belonging to or originating from third parties or links to websites and features in banners or other advertising. Such external links are not investigated, monitored, or checked for accuracy, adequacy, validity, reliability, availability or completeness by us.

WE DO NOT WARRANT, ENDORSE, GUARANTEE, OR ASSUME RESPONSIBILITY FOR THE ACCURACY OR RELIABILITY OF ANY INFORMATION OFFERED BY THIRD-PARTY WEBSITES LINKED THROUGH THE SITE OR ANY WEBSITE OR FEATURE LINKED IN ANY BANNER OR OTHER ADVERTISING.
WE WILL NOT BE A PARTY TO OR IN ANY WAY BE RESPONSIBLE FOR MONITORING ANY TRANSACTION BETWEEN YOU AND THIRD-PARTY PROVIDERS OF PRODUCTS OR SERVICES.

AFFILIATES DISCLAIMER

The Site may contain links to affiliate websites, and we receive an affiliate commission for any purchases made by you on the affiliate website using such links. Our affiliates include the following:

  • makeCNC who provide Downloadable Patterns, Software, Hardware and other content for Laser Cutters, CNC Routers, Plasma, WaterJets, CNC Milling Machines, and other Robotic Tools. They also provide Pattern Files in PDF format for Scroll Saw Users. They are known for their Friendly and Efficient Customer Service and have a comprehensive back catalogue as well as continually providing New Patterns and Content.
  • Cloudray Laser: a world-leading laser parts and solutions provider, has established a whole series of laser product lines, range from CO2 engraving & cutting machine parts, fiber cutting machine parts and laser marking machine parts.
DMCA.com Protection Status Follow @laseruser_com