19 – Laser Cutting Parameter Optimization – Fact or Fiction (40:21)

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Welcome to another Lightblade Learning Lab. Today we’re going to tackle a

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subject which has come up just recently when Thinklaser reported back to me on

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my early videos, asking me, why am I so vague on setting up the parameters for

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cutting. Especially as they have provided me with a data sheet which gives me all the

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cutting parameters for a 60-watt tube. In fact, for all sorts of tubes. Now cutting

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parameters in my opinion is a very inexact science at this moment in time

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because there are so many parameters that affect cutting and any cutting

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parameter chart that you see, only contains the merest hint of all the

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parameters that could vary and affect your cut. Now “Oi mate, can you tell me the way to China?” “oh, that way.”

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I think that’s a fairly good example of what

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cutting parameters are. They’re just a pointer in the right direction. Let me

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just show you for example, some of the things that can affect it. The first and

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obvious thing that’s going to affect your choice of cutting parameters is the

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material itself and then you’ve got the material thickness and then we’ve got

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this one here which I’ve called power available for cutting. We’ve touched on

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some of this stuff before when we talked about mirrors, when we talked about

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lenses. The power coming out of the laser may well be 60 watts, but it’s got to pass

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through three mirrors which, lets conservatively say they lose three

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percent each and then it’s got to pass through a lens which might be another

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

02:04

three percent. So that 7.2 watts that we’ve lost out of our 60 before we start. So we’re

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down to 53 watts. So we may well have started off with 60 watts but we’re

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going to finish up with 53 watts. Now that’s what I’m talking about power

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available and you won’t see anybody talking about power available on any

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cutting parameter charts. They will talk about what your tube delivers, supposedly.

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Not how your machine is set up. So if your mirrors start to get a bit dirty or

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your lens gets fogged up, this number here can drop considerably and it can

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affect substantially the performance of your cut. Now the next thing that affects

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the cut is obviously the cutting speed which you have got control over. When you

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look at the Thunder laser website they do mention different types of lens but

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only one of them is specified as a focal length. The other thing that

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can affect the cutting is, and I’m talking specifically about cutting now

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and not engraving, is the position of the focal point. Now you can have the focal

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point set on the surface of the material or you can drop the focal point so that

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it’s actually inside the material itself and that has a significant effect on the

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cutting performance and the final thing depending on whether you’re cutting

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acrylic or whether you’re cutting some organic material like leather or wood or

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MDF. Air assist is a very important factor which nobody ever seems to

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mention much about. When we see a chart which tells us that for a given material

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and a given thickness all we need to do is use sixty percent power and a speed

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of X that’s only half the story and that’s really what I’m talking about .

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Now to establish cutting parameters for your machine. Only your machine will have

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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all this set of parameters. This is the most important thing on your machine,

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which is the power that you’re delivering because that’s under your

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control. I suppose theoretically any supplier of cutting parameters cannot

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legislate for the quality of your machine.

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So consequently they give you best conditions, but we don’t know the

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condition of their machine when they set it up. Maybe their machine was similar,

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maybe it wasn’t? We just don’t know, so the whole thing about cutting parameters

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is uncertainty and so what I’m going to do is to show you how you can generate

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your own cutting parameters and populate RDWorks with information that is

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pertinent to you and your machine. Now ideally you would like to know what

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power your machine is delivering. Not what power percentage. Percentage is one

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of the worst things I can ever imagine for power but there is no other way of

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defining power unless you have a power meter and you generally keep using the

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power meter as I do to check the power of the machine but that’s because I’m

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purely using this machine to understand and expand my knowledge about this

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technology. The title of this section is cutting parameters fact or fiction. I’m

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sorry I’m going to be a bit hesitant there is a small amount of fact in this

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table if you can find it, but there’s a lot of fiction. Let me point out why i

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don’t use these tables and i use my experience instead. We’ve got a whole

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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range of laser tubes here, the one that i’ve got is a 60 watt tube so let’s just

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focus on the 60 watt. First of all up in the top right hand corner we can clearly

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see that it says use 95% laser power. Well I think we’ve already established

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that ninety-five percent laser power is a killer, it’s not going to do your tube

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any good at all. On my machine at sixty-seven percent power I shall be

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over driving the tube and seriously shortening its life. That immediately

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brings into question the validity of all these figures because if they were done

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at ninety-five percent power in the factory on a machine which on the

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particular day produce those numbers that’s fine, that’s fact. But they’re not

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fact for your machine or my machine. Cutting parameters are a hugely complex

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subject which I tried to stay away from up to now and there is no way that I can

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begin to tackle cutting parameters in one session. If I was using a machine all

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day every day for production. I would, I would focus in on just a few cutting

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parameters that suited me and my machine and my production. I don’t have that

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luxury, I’m an inveterate fiddler I like to understand how things work and as

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such when I look at these tables they are practically meaningless. I keep using

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disparaging terms about these tables and now I think I really ought to justify

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myself by pointing out some of the reasons why I’m being so disparaging.

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Let’s just take this first section here acrylic, I understand acrylic quite well

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because I’ve done a lot of acrylic work. First of all this table is being in the

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process, hopefully by the time you get your machine, this table will have been

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completely revised and a bit more sense put into it, because I’ve already pointed

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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out a lot of problems to Thinklaser. First of all when we look down the

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thicknesses there three millimeters three millimeters hang on shouldn’t that

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be five millimetres or six millimetres or maybe four millimetres but it’s

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certainly not three millimetres. We’ve already pointed out the ninety-five

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percent laser power problem ok let’s look across the top column and let’s

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just focus in on my particular 60 watt tube. We’ve got two columns there, two

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speeds to choose from we’ve got highest speed and a best speed now what does

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that actually mean? As an absolute novice you would come into that and think well

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I can cut that at 20 millimetres a second if I’ve got a 60 watt tube. I wonder

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what the best speed is? Why would I go slower?

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Is it something to do with the surface finish? With acrylic there are two speeds

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that you can cut at, one of them is high speed and you could put high speed with

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a lot of air or you can go slower and you can get a better surface finish with

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using less air. Let’s have a quick look at the notes and sure enough when we

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look over at the notes it says please pay attention to the airflow. OK it’s a little

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bit of Chinglish there, but basically what it’s saying is that if you run with

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low airflow you get a better finish. So there’s a sort of erm, sort of logic

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when you understand how to cut acrylic but as a novice it wouldn’t make any

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sense at all. The machine is supplied with three lenses, a two inch, a two and

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a half and a four-inch lens. I’ve added to that collection with a one and a half

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inch lens of my own manufacture. What do these figures apply to, because they

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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don’t apply equally to every lens? Because the density of the power of each

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lens and its ability to cut changes. So there’s one major piece of information

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missing from this table and that’s the lens that they used to produce this data.

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When you’re cutting thicker materials the lens narrows the beam down to

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something called a focus point if you are engraving you need the focus point

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set to the surface. If you are cutting different thicknesses of material you

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need the focal point set to different depths in the material to get the most

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efficient cut. I’m still trying to find out what Kinef is or kinEF? Should that

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be Knife? Just a bad spelling? As far as I can find out Kinef is a Russian

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oil plant! Umm I’ve got no clue what that means. Now when it comes to MDF and HDF

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with my 60 watt tube they tell me I can run at 15 or 12 millimeters a second. Now

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from personal experience I would never want to run at slower than the fastest

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speed that I could possibly get out of the machine. You put the power up to its

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maximum, you put the air flow, as I mentioned at the end here up to its

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maximum and you see just how fast you can run. The faster you can run for the

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maximum power, the least amount of charring you get on the edge. So why

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would you want to run at slow speed? It’s a puzzle to me? Now this relationship

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between speed and airflow is a subject that we will tackle in a future session.

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It’s a very important subject and it has significant effects when it comes to

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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cutting and now we come on to something which is very very controversial. They

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tell me that I can cut PVC in this table and they give me the parameters for

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doing it. Yes, I can cut PVC, but no I would never cut PVC and i would advise you to

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never cut PVC, because in cutting PVC the chemical reaction caused by heating PVC,

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releases chlorine gas and also hydrogen chloride gas. When it comes into contact

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with moisture it will turn into hydrochloric acid I don’t think I want

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to cover my eyes or my lungs with hydrochloric acid thank you very much

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indeed! And by the way it will have no good effects on the slide ways and the

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electronics in your machine. Well I think that’s enough critical comment about

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that table and one of the reasons why I don’t use the table that was supplied

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with the machine. I must reinforce the fact that I said at the beginning Thinklaser

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are no different than any other company, any parameter table that’s

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supplied lacks information and is only a guide.

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The fact that this one possesses some dangerous suggestions had been pointed

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out to Thinklaser and they are in the process of correcting that. So by the

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time you get your machine and look at this table it will probably be

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unrecognisable. To justify what I’m saying about all cutting parameter

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tables, I’m going to take you to one of what I consider to be one of the

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slightly better researched sets of data out there and that’s on a site called

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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Thunder Laser now they provide you with set of parameters for these different

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wattage tubes they haven’t tried to put them all on to one table they’ve kept

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them on separate tables. So we take a look at the parameter table for my

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particular 60 watt laser. Now these tables are slightly better than the

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other set of data that we looked at, because first of all they tell me that

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this is a standard later head and so this data applies to a 2-inch lens and

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again we’ve got just one speed, maximum power and it says powering corners. Well,

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I think as far as the setup is concerned that’s max power and min power. We

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haven’t tackled this subject of Max and min power for cutting this is yet

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another complex subject which which will deal with in a future session, but at

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least there’s an attempt here to show you that there are two possible powers

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that you can use. So this table is slightly more informative. Again we’ve

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got thicknesses and we’ve got just one speed now and we’ve only got one speed

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for acrylic. There is a catch-all at the top here which covers them to a certain

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extent which basically says suggested parameters for some materials. They’re

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not saying these are absolute parameters, suggested parameters and it says

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again the parameters might be different according to different machines.

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Now the other thing that you notice about this table is they do mention foam

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in here, which depends on what sort of material plastic you’re talking about, it

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could be producing toxic chemicals. Research it very carefully before you do

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it. I have pointed out in the hazards of materials, that you should be very

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careful with plastics and when we get down here they do mention plastics. Oops

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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we don’t suggest you do them. So with a two inch lens they’re only giving you

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information regarding 2.3 millimeter thickness and 2.7 millimeter thickness

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and five millimeter thickness. So they’re not really giving you too much

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information here, these are very much more of an outline guide. They also

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mention cutting with a four inch focal length lens but they don’t mention

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cutting with what they call their high resolution laser head. Now the high

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resolution laser head, I think, but I’m not absolutely certain. I think that

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basically is a one and a half inch lens. Well here we are back at the machine I

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promise I’ve finished my rant about the dubious nature of the existing cutting

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parameter charts that are available, not just from Thinklaser, but basically

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wherever you go they all suffer with the same problem. Too little

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information to be of any serious relevance to you, to repeatably set up

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your machine. I suppose in a strange sort of way I’d feel a bit like my mum used

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to, I alwaysremember my mum being able to just go to the cupboard take out all the

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ingredients for a cake throw them into a bowl and a cake magically appeared and

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it was perfect every time. Now I don’t look at a recipe book, I don’t look at

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cutting parameters. Within two years i have gained a great deal of, I don’t know how to word it.

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Perhaps the word, “feel” is the right word to use. I understand how various

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lenses affect the cutting, I understand how airflow affects the cutting. I

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understand how speed affects the cutting and power affects the cutting and I mix

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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all these ingredients together in my head when I’ve got a problem, and I come

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up with nearly the right solution most of the time. Now, as a novice you don’t have

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that skill or that ability and I don’t know whether it’s something that’s unique

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to me or whether I’m getting plain bloody lazy because I don’t want

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to go through all the work of filling in cutting parameters that I’m just

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about to demonstrate to you. We’re running out of time in this session to

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actually do any real cutting parameter test work, but I promise you in the

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next session we will spend the whole of the session going through ways in which

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you should or methods to approach setting up cutting parameters and

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filling them int o charts. Now the cutting parameters that I should be telling you

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about will be complete they would be just like a Jamie Oliver recipe. You will

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be able to follow them and provided your machine is the same as it was today when

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you left it yesterday they will work and if it doesn’t work it means that

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there’s something wrong with your machine and that’s the great thing about

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having exact cutting parameters it keeps an eye on the health of your machine. No

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today we’re going to finish off this session by looking at some of the rather

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key features that your ought to add to the notes when you’re doing your

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parameters set up. Because there are very important things that you need to

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understand but they’re things that nobody ever mentions in any parameter

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charts that I’ve ever seen. It all comes down to experience, but experience should

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be included in your cutting parameter chart. I’ve put my glasses on to look a bit

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more studious and away we go. Now how many cutting parameter charts have you

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ever seen where they mention anything about the extraction? How many parameter

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charts have you ever seen where they tell you exactly what you should do with your

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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air assist? There are some vague references to it in the Thinklaser

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charts, but they are vague references. As a novice you would not understand what

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they mean, as an experienced person i can read into them what I think they mean.

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Right, now what I’ve got here are some of this card that I used for my focus ramps

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and so that I don’t waste my time and effort, I’m going to make some more focus

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ramps. Now I’ve got three sheets here to make three focus ramps in three

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different ways and I’m going to demonstrate some very critical things

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about performance of this machine using that piece of cardboard. I’ve got a two

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inch lens in there. I’ve got a piece of card here, if I was sitting on the

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honeycomb bed with the airflow on there’s a possibility, only a possibility

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that it will sit flat, but bear in mind what we’ve just done

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with focus. It’s quite important that you try and make sure that any job that you

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put on here is flat. Now as you can see this cardboard is not flat and I can

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turn it over and the ends are sticking up in the air well to be honest it’s

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much easier to put the sticky up ends downwards and pull the middle down. We can

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either put little teeny weenie pieces of metal along the edge here so now we’ve

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got a flat piece of material. Key issue number one. The first thing I’m going to

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do is to raise up the table to almost its highest extent so that it’s more or

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less level with the top here.

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And there’s a good reason for doing that which I’ll explain to you shortly. So I’m

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going to set that to five millimetres so what I shall do, I will drop that down

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on to the five millimetre step and lock it up. To make sure that my air supply, and I’m

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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going to take this off of it so you can hear it.

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It’s running completely flat out, it’s off and it’s fully on. So I’ve got full air

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assist and the only reason I’m doing that is because you can’t really hear it

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under there. I’m going to turn the extraction system on now.

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So we’ve got plenty of airflow passing through here,

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it’s not as good as it could be because we’ve blocked off a lot of the flow

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because of this table here but what I want to do is demonstrate to you one or

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two things. First of all we still got good airflow through here and we’ve got

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our air assist on here.

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I’ve just, I can hear something, I’m sorry I’m going to stop that.

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I’ve got the power set to fifteen percent for that engraving and I’m going

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to turn the air off.

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Can you hear how noisy the cut is? Hear it?Now I’m gonna stop that. Because I’ve got the

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power set to fifteen percent. Now a completely different subject which I

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will have to tackle at some future point in time is high frequency impact

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engraving. It’s a very strange characteristic and a very useful

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characteristic that you get with a laser tube of good quality. You will hopefully

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see how clean the engraving is, there’s not much smoke damage on there. It is,

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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even though I’ve got the air assist on, I’ve got basically quite clean engraving,

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that’s because I’ve got this noisy type of Engraving. Now I’m going to change the

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power from fifteen percent to sixteen percent. In fact I’ll go to seventeen

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percent to be sure that I’m clear of this zone.

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Okay, now for the for the moment i’m going to leave the air off so that we

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can hear the difference between this, I’m calling it engraving but it’s not, it’s

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cutting at very low power so that it doesn’t actually cut through. It’s not

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proper engraving.

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See how quiet it is? Lets turn some extraction on now.

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Now you’ll notice I’m cutting this straight down onto a piece of steel and it

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is giving a slightly hissy effect which is not the laser beam itself but it’s I

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think a reflection off the steel underneath.

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There is a bit of um misting on that surface there, these, these lines look as

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though they’re a little bit brown on either side but that’s where the smoke

25:43

has actually blown back onto the surface of the lines and made them just like

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shadowy. But that’s not the only problem that we’ve got with this

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approach.

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We have two problems; number one we’ve blown out a huge amount

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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of tar, in other words the cellulose when it’s cut produces this tar like residue,

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because it’s a wood it’s a resin in there and it’s all sticky on the table now

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that’s a major disadvantage in one way but hey if it wasn’t on the table it

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would be in the filter. That’s what’s not on the back of the product, so this

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really is not a very satisfactory approach for cutting things. As I said, the

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only good thing about it is, that with a little drop of this

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it’s on there not in the filter but it’s not until you see something like that

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you realise just how much stuff is going out into the filter.

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It’s even worse with MDF, ten times worse with MDF and you also get a similar

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sort of residue but it’s a white sticky clear residue or a coloured

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residue when you cut acrylic, Acrylic produces straight um methyl acrylate

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solution, which is a horrible white sticky

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material or if it’s a coloured acrylate it’s a, it’s a coloured material. But now I

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want to try and solve two problems at once. If we take a look at these you’ll

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notice that they’ve got a sort of a bit of a shadow dusky hue to them. With

27:45

your air assist you’re actually blowing the smoke back and painting that smoke

27:51

debris back onto the surface, so the last thing you really want to do is to have

27:58

your air assist on. First of all if we turn the air assist off, which I

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

28:03

have done now, the problem is that we’re likely to smoke the lens. So what we need

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to do is to make sure that we’ve got lots of air flow passing across the job

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so that we don’t stand any chance of doing just that. The way that we’re going

28:20

to achieve that is by dropping the table down a bit the first thing I’ve done to

28:25

stop the rubbish from collecting underneath here so we should finish up

28:30

with clean surface underneath and now what we want we want air flow passing

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underneath a small amount but we want a lot of air flow across the surface

28:43

because the smoke comes up and we don’t want to blow it back down again we want

28:48

to push it away as quickly as possible and the way that we’re going to achieve

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that is by going into the Z-mode and dropping the table down so that the

28:58

table sits approximately level with this surface here. There we go, that has dropped on nicely.

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and now what I’m going to do I’m going to move this as close as I can to the

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front edge of the machine. So here I am within an inch or so of the front of the

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machine.

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On this lid, I have attached some 1/2 inch thick rubber pads, so the door has got a

29:31

half-inch gap underneath it and that will allow a jet of air to fly

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across the top of the job and I’ve made sure that that happens

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because I’ve got this solid piece of metal in here which has blocked off the

29:47

air that would normally pass down through the table. So the only way for

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the air to get through this machine is to get out the back here to those

29:57

grills at the back there and to do that it’ll fly straight across the top of

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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this job.

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And there we go we shall have to look through the window this time.

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Unusual for me to run the machine with the cover down but in this particular

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instance is essential. So I’ve turned the air assist off, I’ve set the focus

30:19

correct and we’ve got plenty of air flow zipping through this gap underneath the door.

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Now I think you can see the smoke being drawn away at quite high speed.

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Now when we get to proper cutting there is a moderate chance that we may actually

30:51

see some flames on top of the work because the smoke that’s coming up, bear in

30:58

mind has got a lot of fumes in it. Now we are okay at the moment we’ve got no fire!

31:11

You can see how well we’re drawing the fumes away.

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There we go, Flames.

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We could just stop that.

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And what we’ll do, we’ll turn on just the merest amount of air assist

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and the way to

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check that

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is to take this off.

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and listen for it.

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there we go just the merest amount to blow air out of the nozzle.

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

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I mean all this stuff, the original stuff there’s no smoking at all and then let’s

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take a look at the back

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completely clean at the back and what have we got on the table?

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Absolutely nothing because the smoke that’s been drawn away.

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So there’s something about to set up of the machine that you

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really need to make make a note of if you’re doing cardboard for example.

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Make sure you cover the bed and you get a linear air flow across your job. Turn

32:55

off the air assist. We will now reinstall the honeycomb bed. And

33:07

you can feel or hear

33:11

although this is, got air passing down through it, it’s still not enough to suck this

33:18

completely flat.

33:24

That’s because we’ve got so much air around the outside that we don’t have

33:30

enough differential pressure here to suck this down onto the table. If it was

33:34

thin paper there may just be enough there.

33:39

Now the problem with this is we’re going to be working on this top surface here,

33:48

and most of our air is going to come in and go down through here. So we’re not

33:54

going to be able to use this honeycomb bed without any air supply. So we’re on

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

34:00

a loser to start with if we try and do engraving or cutting on a surface like

34:06

this which will smoke up.

34:09

But I will demonstrate that to you anyway.

34:16

Now you would automatically think, remember, remember how we produced

34:21

horrible tar-ry shapes on the flat metal surface?

34:26

There’s absolutely no reason why we won’t produce the same touring shapes on here

34:32

because there is no airflow underneath this table.

34:38

You might immediately think there is because there’s honeycomb under there but hey

34:43

all the air is passing down the outside we’ve got no air passing down here at

34:49

all and so each one of these little cells is a dead cell we’ve got virtually

34:56

no air movement underneath this piece of metal underneath this piece of cardboard at

35:00

all and even when we cut through it there will still be very little air flow

35:04

because the only air flow that we’ve got will be passing down through the cut.

35:10

So there’s a pretty fair chance that if we

35:14

leave it like this, we will still finish up with some tar-ry marks on the back

35:20

but we’ll try it and we’ll see what happens.

35:32

It doesn’t do it as it comes towards us, it only does it as it moves away

35:35

from us you notice. Something to do with the airflow.

35:44

That’s because the cut, the smoke that is coming out the back of the cut, that’s

35:49

what it is.

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

36:07

It might look a bit mucky and it is mucky for several things; first of all

36:12

we’ve got these cuts that have nearly come through so we mustn’t take any notice

36:16

of those but what you can take a look at are all these marks along here look

36:21

every time it crosses over a piece of the honeycomb table we get a mark.

36:29

Especially where the table has already been marked up and it burns off the,

36:35

off the honeycomb back onto this surface. All this debris that’s on here is

36:43

actually burning off back onto the back of the card so that’s another good

36:49

reason why you’d want to stand your job off of here so you get plenty of air

36:53

flow past it as well. Right so I’ve done a couple of things now, first of all we

36:59

put some stand-offs on there

37:04

So we’ve got air underneath, we’ve got air across the top, we’ve got no air assist

37:10

on.

37:13

I’ve wound the….

37:16

I’ve wound the um lets call it the engraving speed up to 180 millimetres a second and I’ve put the

37:23

power up to 18 percent to try and get rid of this hissy cut.

37:29

37:33

There’s a hint of that cut coming back, can you hear it?

37:38

And that’s even at 18-percent. See when the smokes blowing away from the cut, now

37:45

what happened is that the smoke is coming out the back of the cut towards us and

37:48

having to draw all the way around the nozzle, can you see that?

37:56

Now the smoke is coming this way. Well in the overall scheme of things

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

38:03

that’s probably the best one so far. We can compare that with a sort of typical

38:08

example of something that has been done with air assist. You can see the difference here

38:16

with the air assist how we’ve blown the debris back onto the surface and here

38:22

we’ve allowed the debris to come up and be drawn away by the rapid air flow in the

38:27

machine itself. Now those are the sort of subtle changes and subtle things that

38:34

you need to make a note of when you’re setting up your parameters but nobody

38:38

will be telling about these in any parameter library that I’ve seen. So once you

38:42

get your job right, you will need to make sure that you note the type of table you

38:47

are using, whether you are using stand-offs, whether or not you’re using air assist or not, and

38:54

somebody’s going to say ooh, using no air assist means we could smoke the nozzle,

38:59

we could smoke the lens. Yes I agree there is a possibility of that ,so

39:03

what we’ll do…. let’s just have a look at the lens

39:08

I would say there’s zero damage to that lens. There’s no smoke getting up in

39:14

there and why well I think it could be something to do with the power that we

39:19

were using. The fact that we had a flame there and the flame means that we

39:24

were burning the smoke and it was not getting a chance to go back up

39:28

inside the nozzle or when it wasn’t burning it was being drawn off so

39:33

quickly that it never had a chance to get back up inside there. Well thanks very

39:36

much for persevering with me today it’s been a bit of a grumble session but I

39:41

hope in the end we found out some interesting stuff and this is a prelude

39:45

of the sort of way that we will be tackling in the next session. We shall

39:51

be doing things that you probably won’t see demonstrated elsewhere but hopefully

39:55

I should be able to give you some tips on how to quickly get to the best

39:59

cutting parameters for the job that you want to do. The procedure is the same for each,

Transcript For Laser Cutting Parameter Optimization – Fact or Fiction (Cont…)

40:06

it’s just that you’ve got to spend a lot of time doing it and I don’t always have

40:11

that much patience. Which is why I just pick them out of the air. Thank you very

40:17

much for your time and I’ll see you on the next session