15 – Is Ordinary Laser Engraving Another Disappointment?

0:00[Music]

0:03it’s almost like a little sewing machine

0:05isn’t it

0:08welcome to another session with my

0:10tangerine tiger now what you’ve seen

0:12there

0:12is a quick test that i’m carrying out to

0:15see if i could find out what was going

0:17on

0:18because i noticed one or two strange

0:20patterns

0:21when i was doing my photo engraving last

0:24time

0:25now whether i was doing pictures this

0:27way if we take a look here you’ll see

0:29that there’s some

0:30sort of patination that runs across the

0:33picture

0:35this picture was done this way and we’ve

0:38got

0:39patinations that run across that way

0:42this picture was done this way and we’ve

0:45got those same

0:46narrow lines there and the lines get

0:48they almost disappear at the top there

0:51and here they’re pretty obvious down the

0:53bottom here

0:54they’re not exactly all the same pitch

0:57and then they tend

0:58to disappear to nothing as we get

0:59towards the top and look we’ve got the

1:01same things again happening here

1:03so this is not any sort of aliasing

1:07pattern

1:08within the actual software itself

1:11this is a machine problem of some sort

1:14the only machine problem that it can be

1:16is to do with the drive belts on the

1:18y-axis

1:20but hey these are not curtains in the

1:23same way

1:24that we saw curtains on the x-axis

1:26they’re more than three millimeter pitch

1:28and secondly they’re not uniform as we

1:31get further

1:32into the stroke the gap gets wider and

1:36wider

1:36we’ve got a little bit of a problem

1:38there which i think i understand what

1:40the

1:40problem might be and the very simple

1:42test

1:43that i carried out was to see if i could

1:47identify the same pattern as i worked up

1:49that strip

1:52to be honest the answer is no there

1:55seems to be very little problem there

1:57but

1:58i’m pretty sure i do understand what the

2:00problem is to do with those belts

Transcript for Is Ordinary Laser Engraving With a RF Laser Another Disappointment? (Cont…)

2:02and we will have a go at trying to fix

2:04the problem or identify the problem in a

2:06later session

2:08it’s not important at this moment in

2:09time for some of the stuff that we’re

2:11going to do

2:12but it is an interesting problem which i

2:14will come back and investigate

2:15because today i want to step onto some

2:18rather

2:19hallowed ground the whole point about

2:22these rf machines

2:24is that they’re supposedly good at doing

2:28just ordinary engraving whether it be

2:30bitmap text and logos

2:32or whether it be filled vector graphics

2:34it doesn’t matter

2:36this machine is supposed to be super

2:38fast at doing that when i look at the

2:40demonstration videos

2:42yes you can see that the machine is

2:44going very fast

2:45just like you saw my little sewing

2:47machine going very fast here at the

2:49beginning

2:50so today we’re going to as i said step

2:52onto that hallowed ground

2:54and take a look at what might be going

2:56on

2:57with just ordinary engraving the

3:00simplest thing that we could possibly do

3:01the great thing about this machine is we

3:03know

3:04that it will do superb quality engraving

3:07because it switches on

3:09and off so quickly so speak technically

3:12speed is not an issue here we’re not

3:14limited by the power supply

3:16the response time of the power supply

3:18what we are limited by

3:20is physical power as i’ve explained to

3:24you several times before

3:26candle flame put your hand over the

3:27candle flame

3:29move it fast enough and you won’t feel

3:30any heat at all but move it slow enough

3:33and you damage your hand now that’s

3:35exactly what happens to this paper

3:37the faster you move it the less energy

3:40you’re putting down

3:41per distance and the lighter the cut

3:44will become

3:45and the thinner the line will become if

3:47we’re running fast

3:48if you have limited power available to

3:50you there are really

3:52only two parameters that you’ve got to

3:56affect damage to the material that

3:58you’re cutting now

3:59every material will have a different

Transcript for Is Ordinary Laser Engraving With a RF Laser Another Disappointment? (Cont…)

4:01damage threshold

4:03but that damage threshold can only be

4:06exceeded

4:07if you have got enough power to damage

4:09the material

4:10and the only way that you can control

4:12that damage is either by moving

4:14slowly or by doing a small amount of

4:17damage

4:18multiple times you’ve only got those two

4:20choices

4:21the fact that this system is controlled

4:23by the pwm seat i’ve either got 20 watts

4:26when it’s switched on or know what’s

4:29when it’s switched off

4:31i’m doing engraving i don’t want any

4:34dead periods

4:36i need 20 watts all of the time

4:39so i’ve got to set this onto basically

4:42100

4:43power which basically means i’m not

4:46going to have

4:47any of these i’m going to have a

4:49straight line of 20 watts continuously

4:53so there is no point in having a pwm

4:56controlled machine when you’re doing

4:58engraving the machine will switch off at

5:00any black white interface

Transcript for Is Ordinary Laser Engraving With a RF Laser Another Disappointment? (Cont…)

5:02instantly and quickly regardless of the

5:04pwm signal that immediately asks the

5:06question

5:07what’s so fantastic about rf technology

5:10as i mentioned to you when we’re

5:11comparing the the rf

5:13and the glass tube system rf

5:16radio frequency is only a different

5:18means by which we’re producing

5:20the laser beam itself this control

5:23system here

5:24the pwm control system seems to be

5:27unique

5:27but it doesn’t seem to be a positive

5:29advantage yes

5:31you’ve got power control but it’s not

5:33really power control

5:34because every time you turn the machine

5:37on you’re putting

5:38out the same level of power it’s just

5:41that

5:41on average which we’re not worried about

5:43because we don’t do

5:45average damage we might use average heat

5:48if we were doing welding or something

5:50like that but when we come to damaging

5:52material

5:53every time the pulse is on at 20 watts

5:55it’s doing 20 watts worth of damage

5:57just because it’s on for 50 percent of

5:59the time doesn’t mean to say it’s doing

Transcript for Is Ordinary Laser Engraving With a RF Laser Another Disappointment? (Cont…)

6:0110 watts worth of damage

6:03that’s the puzzling thing that i can’t

6:05understand about this technology

6:07it’s basically constant current

6:09technology

6:10diluted by pwm am i being naive about

6:14this

6:15for our first test we’re going to carry

6:18out one of the

6:19party pieces that you’ll see the rf

6:22laser

6:23performing at any exhibition that you go

6:25to

6:26the aztec calendar huge amount of detail

6:29on there so i’m going to run this at a

6:31thousand

6:32millimeters a second 100

6:35power it really doesn’t matter what the

6:38frequency is because it’s not going to

6:39come into play

6:41and we’re going to use my standard pitch

6:44of 0.1

6:45which is roughly going to be the

6:47thickness of the lines that i can

6:49produce

6:49remember the candle i’m not expecting a

6:52great deal of

6:53damage to take place

6:56at that sort of speed and that amount of

6:58power but let’s give it a go and see

7:01what we get now

7:01what i’ve got here is a piece of beech

7:04faced

7:04plywood

7:08well i’m pretty impressed to start with

7:11that’s

7:12more color than i thought i was ever

7:13going to get

7:20and that’s a thousand millimeters a

7:22second

7:25okay so i am impressed by that

7:30we’ve found a party trick that it can

7:32perform well at

7:37but it is playing to the strengths of

7:38this machine which is an extremely fast

7:41switching capability

7:44the color is something i wasn’t

7:47expecting

7:49and that took two minutes 34

7:52so that’s pretty good going um i have to

7:55say

7:57for the first time i am impressed with

7:59something this machine can do

Transcript for Is Ordinary Laser Engraving With a RF Laser Another Disappointment? (Cont…)

8:01this is a picture i borrowed off of

8:03wikipedia

8:05consider that against the size of my

8:07hand you can see that it’s

8:09some of this detail in here is very very

8:11fine we look at the incredible detail on

8:13there

8:14considering the size the relative size

8:16of my finger

8:19i’ll have to give this 10 out of 10 for

8:21the moment

8:22i’m very impressed with that bearing in

8:25mind it was a roundabout if i remember

8:27two minutes thirty something or other um

8:30we’re now going to run the same thing

8:31but we’re going to try and do it at 1400

8:34millimeters a second and see how the

8:35color

8:36changes just ordinary text and graphics

8:38is going to be easy

8:40after looking at this amount of detail

8:50it’s 33 which is about the same so

8:53really speed

8:54didn’t make a great deal of difference

8:55because in running faster

8:57we’ve got a longer over track impressive

9:001400

9:01yes but a thousand gives me a deeper

9:06color as you would expect

9:09so with no difference in time

9:12that’s got to be the choice running

9:14slower actually produces a better result

9:17for no extra cycle okay let’s try on a

9:20piece of poplar plywood now

9:22we’re going to run this at 1200

9:23millimeters a second

9:27now the burn characteristics of this

9:29material are completely different than

9:30that of

9:31plywood that’s actually that’s actually

9:34the grain that’s running through the

9:36material which is affecting the color

9:37here it was 1200 millimeter second so

9:40even though we’ve run that slower we’ve

9:43still got

9:44roughly the same time 232 okay let’s try

9:47a piece of mdf

9:48and run this at a thousand

10:02so yes it’s doing a remarkable job on

Transcript for Is Ordinary Laser Engraving With a RF Laser Another Disappointment? (Cont…)

10:04mdf

10:06i have to say i’m impressed at how far

10:0820 watts is going

10:10see that was two minutes 34 we’re

10:12running slower

10:13but it’s not taking any longer but we’re

10:16getting a nice

10:17dark cut that’s remarkable detail isn’t

10:20it

10:22so again i’ll ask this very

10:25silly naive question why have we got

10:27fancy pwm

10:29control on this machine what’s it for at

10:31the moment

10:32i don’t know because

10:36we’re running this without any pwm at

10:39all we’re running it at 100

10:41like a cw like a like a constant power

10:44machine the only

10:47thing that we’ve got is this remarkably

10:50fast

10:50switching speed which is producing

10:53amazing results i mean i’ve got this

10:55machine up to 1400 millimeters a second

10:58scanning and look it’s doing a fantastic

11:02job i’ve got a slight coaster here

11:05i’m not changing any of the settings at

11:07all

11:08thousand millimeters a second directly

11:26even on sleep it’s done a pretty

11:28remarkable job hasn’t it

11:33all right let’s see what it can do with

11:34a piece of cast acrylic should we

11:36seem to be doing a very good job

11:38straight out the box

11:40with it’s not covered in dust or

11:44anything like that look

11:49you just put it against a black

11:51background and you can see how good

11:53it really is

11:58not only is it a nice white colour that

Transcript for Is Ordinary Laser Engraving With a RF Laser Another Disappointment? (Cont…)

12:01hasn’t produced all sorts of fumes

12:03everywhere

12:05it’s absolutely stunning detail

12:09all down to the response time of the

12:10switching of the beam

12:12so we found the major strength of this

12:16machine at last

12:18but just bear in mind

12:22we’ve tried all these materials we’ve

12:24not changed it into the settings

12:26we’ve not used the pwm

12:29we’ve just thrown stuff at the machine

12:34i’m pretty impressed with this aspect of

12:37its capabilities

12:38trying a different sort of engraving

12:41what you saw me doing before was what i

12:42call

12:43drawing or normal engraved there are two

12:44other sorts of engraving one of them is

12:46an architectural technique

12:48called relive which basically is almost

12:51like 3d

12:52engraving where you all the white

12:55for instance in that picture or all the

12:57background in that picture

12:59will be etched away and it will leave

13:03the black lines on the surface so the

13:05black lines will be white

13:07and the background will be relieved away

13:10and that’s one technique this technique

13:13that i’m experimenting with here is a

13:15slightly different technique it’s a

13:16printing technique

13:18and it’s called intaglio now

13:21basically intaglio is where you make a

13:23wooden pattern

13:24like this or a pattern like this and you

13:27size the lines into the pattern

13:30deep enough so that they will hold ink

13:34and the idea is you put your paper over

13:36the top then and put a roller on top and

13:38lift the ink out of the grooves

13:40so you’re basically incising deep

13:42grooves

13:43into your material i’m achieving that in

13:46this instance

13:47by slowing the job down

13:50that’s the only way i can get more power

13:52into this job either

13:54slow it down or add more lines

13:58so that i over burn now i’d much rather

14:00slow it down and go over the job once

Transcript for Is Ordinary Laser Engraving With a RF Laser Another Disappointment? (Cont…)

14:03than do multiple burns but we will

14:06compare the two

14:08so i’ve reduced this to 500 millimeters

14:10in second

14:11instead of a thousand millimeters a

14:13second and it’s looking

14:14pretty good and clean yeah there is some

14:17depth to that but not very much

14:19let me try the same thing again but this

14:21time i’ll run it at

14:23250. so it’s going to take four times as

14:25long this is now

14:26going to produce a lot deeper burn i’m

14:29going to produce more smoke

14:30and i hope i’m not going to brown the

14:34surface too much

14:35i am using my compound lens here so it’s

14:37producing a very very fine

14:39burn line

14:48really a dark very crisp image

14:52i’m again quite staggered and amazed

14:56at what we’re actually capable of doing

14:58here

15:00now when i was doing this at a thousand

15:02millimeters a second you will remember

15:03that

15:04i think it took uh two minutes

15:0730 roughly

15:11but if you take a look now you’ll see

15:12that the amount of over travel is

15:15almost nil

15:19so whereas you would expect because i’m

15:22running at a quarter the speed

15:23it might take four times as long

15:27i suspect it won’t take

15:30what 2 30 will be 10 minutes

15:355 minutes 47 we’ve dropped the speed

15:39to a quarter and we’ve only

15:42about two and a quarter times increase

15:44the cycle time and yes we’ve definitely

15:46got some

15:47depth to that now so we’ll see whether

15:50we can

15:51run even slower now and get a deeper cut

15:55we’ll drop it down to 125 millimeters a

15:58second

15:59i haven’t got my extraction set up on

Transcript for Is Ordinary Laser Engraving With a RF Laser Another Disappointment? (Cont…)

16:01here at the moment because i didn’t

16:02think i’d need it but

16:07yeah it does need some extraction now

16:10this is

16:11one eighth of the speed that we started

16:13off with at a thousand

16:14millimeters a second and a thousand

16:17millimeters a second

16:19we were doing two minutes thirty two

16:21minutes 34 i think

16:24so therefore at an eighth of the speed

16:26you would say well it’s going to take

16:28eight times longer

16:29instead of two minutes 30 it’s going to

16:31be

16:32nearly 20 minutes but the more i watch

16:34this thing work like this the more i’m

16:36becoming impressed by it

16:37okay it didn’t do what i originally

16:38planned to do which was my

16:40photo engraving which was the dream that

16:42i had fast photo engraving but

16:44hey this is doing an absolutely

16:46marvelous job

16:47of some other things there’s a lot of

16:49depth in those grooves now

16:51double that time would be what 10 11

16:55nearly 12 minutes and this one took

16:5910 minutes 50

17:03i’m extremely impressed by that do the

17:05same thing again but this time

17:07i’m going to run it instead of single

17:11lines i’m going to run at a thousand

17:14millimeters a second

17:16and quarter the line spacing in other

17:18words i’m going to put down a .025

17:21line spacing

17:24now i think you can immediately see that

17:27by

17:28burning over the same spot four times

17:34we’re not producing such a clean image

17:36we’re getting that browning effect

17:42let’s see what happens if we change it

17:43to three times

17:55let’s try again with point zero five

17:58see now we’ve got we’ve got a crisp

18:00clean image now

Transcript for Is Ordinary Laser Engraving With a RF Laser Another Disappointment? (Cont…)

18:05whereas the other two look over burnt

18:15so i’ll let this one go to halfway and

18:16work out roughly what the time is

18:21and that took two minutes 42

18:23approximately the same

18:24cycle time this one was done at a

18:27thousand

18:28this one was done at a thousand

18:30millimeters a second

18:31with a 0.05 line spacing

18:35this one was done at 250

18:38millimeters a second with a 0.1

18:42line spacing

18:45the quality of the color is much better

18:49and the cycle time is virtually no

18:51different even though

18:52this one is running four times faster

18:56than that one you can very clearly see

18:58the um

19:00the brown hue that we have around here

19:03because we’re just basically engraving

19:06too deep

19:06this was four point zero two five lines

19:10and this was 3.033 lines

19:14and this was a 0.05 line both of these

19:17lovely clean images were done with a

19:190.1 line

19:22just one pass try something a bit more

19:25manageable

19:26a little less ambitious

19:27[Music]

19:34now we’re going to do exactly the

19:36opposite

19:41but i mean that is pretty good isn’t it

19:46there is no relief

19:55and there we go we’ve got some relief

19:57engraving now

19:59well it’s getting a windy night out

Transcript for Is Ordinary Laser Engraving With a RF Laser Another Disappointment? (Cont…)

20:01there now

20:03this time i went in and had a cup of

20:04coffee

20:07i’m going away with a bit of a smile on

20:08my face at the moment because

20:10at least it’s doing what we all expect

20:12it to do

20:14it’s an engraving machine and it’s a

20:16fast

20:17engraving machine the fact that it’s

20:19rather disappointing at photo engraving

20:22well we found ways around that to make

20:25it half decent at photo engraving

20:29the next test will be its achilles heel

20:32cutting let’s see what it can do for

20:34cutting shall we next time

20:37thank you very much for your time and

20:38patience and I’ll catch up with you then