5 Diode Laser Myths That Just Won't Go Away

hey it's Steve welcome back now I spend a lot of time on YouTube obviously and a lot of it is to read comments from my viewers but I also spend quite a bit of time reading comments on other other YouTubers channels as well as other YouTubers comments and frankly I'm getting a little annoyed by some of the misinformation that I've seen happening so in this video what I want to do is look at five of the most common myths related to these diode lasers and dispel some of those those rumors and hopefully give you a little better understanding of both how the laser works and you know whether all these comments you're hearing are true or not so let's get started now most of the myths I want to dispel in this video relate to laser power and and how the the laser reacts to to that power so what I did was I went to my my storage bin and I dusted off a few lasers because what I want to do is cover the range from 5 watts to in this case 33 Watts you could certainly go higher but you'll see that things are pretty much the same and I lined up four lasers that I I really spanned this range so first on the list is the sculpt fun S35 watt laser and it'll be our our test case next I have the creality Falcon 10 10 watt laser and a third on the list is the longer Ray 520 watt laser and finally I have since I had it in the shop the ecmer P2 33 watt laser all right so most of the tests I'm going to do relate to cutting and that's because that's where most of these Mists start and I popped up a list of measurements I'm going to take here so the first one is a simple calculation based on the beam power and the beam size what is the energy density of that particular beam then I'm going to do a standard material cut test and I'm going to run that exact same test with the exact same settings on every laser then I'm going to do a fastest cut test and to stack things up to make it simple the cut the thing I'm going to cut is a curve test and then I can measure the curve as well so so those are the tests and it will be really simple and you can reproduce this on your own laser if you want now along with the tests I wanted to lay down a couple of guidelines here so you know that I'm on the up and up here uh first I have no vested interest in which laser wins this really isn't about winning and losing it's about understanding the characteristics of each of these lasers at this at these given Powers uh next uh the focus here is on the actual laser not the performance of the overall product so in in cases where the laser supports air assist I won't be using it it it will just be the laser working on its own and finally each test that's performed here and I'll show you some of the results each test that's performed here will be run on exactly the same piece of material I bought a big slab of eighth inch plywood from from a local hardware store and cut it up into squares and those are the things I use so that all of these things come from the same exact piece of material with the test criteria out of the way the very first thing I did was run a material test on each of these lasers now it wasn't just any test I ran the exact same test on each of these lasers and I'm showing it to you on screen here because I want to be able to have you test this on your own laser and I went from 70 millimeters per minute up to 700 millimeters per minute and Power on the horizontal from 10 to 100 percent and that gives us 100 squares to look at and some of them on each of these lasers will be cut out and some certainly won't now keep in mind that this is material sensitive so I'm using again typical eighth inch Hardware hardware store plywood if you're using a different material you may have to adjust these ranges a bit but hopefully you can find something similar so I ran the material test on each of the four lasers in the test group and the first one is the 5 Watt and you can see it did cut some some out there now the scale is wrong there it's millimeters per second but it's the same speed the 10 watt Cuts quite a bit more than the five the 20 watt certainly Cuts more than the 10 and the 30 watt cuts the most and this isn't surprising but it's something we'll roll into the results and we'll talk about as we're talking about some of these myths the last piece of information we need to dispel some of these myths is a curve test and I killed two birds with one stone here so I determined the fastest speed that I could run the test and cleanly cut through the materials so that I could then measure the kerf and while I was doing that I actually timed the test so we get a good a good choice of both the kerf and the time it took to run it so we can determine how much faster or slower a given laser of a certain power is there wasn't a whole lot of testing and data collection I needed to do to help dispel some of these myths I'm going to talk about but I rolled it all into this table and you can see the first two rows here come from the manufacturer spec sheet the power can be a bit dubious because manufacturers like to mislead us a bit but I did my best to determine what the actual power at the output of the tube is as opposed to what the manufacturers sometimes do which is add up the number of diodes in the box there will be some loss and I'll talk about that later but it's generally pretty close to to what the manufacturer is telling you here the spot size you can see there's two two camps here there's the 0.06 millimeter square beam size and then the quote unquote giant by some people's measure 0.08 by 0.1 millimeter beam and I use those two numbers to calculate the energy density now what this number actually is is to say if the beam was a one millimeter square how much energy would be in that beam when it's when it's on hits the material and you can see from the Left End where we have a low power laser to the to the top end the 33 watt is roughly four times the power energy density as as the the five watt laser uh the cuts the cut tests were all run at 100 power and I determine through some experimentation the absolute fastest I could run on this material and get a clean cut through and the thing I was running of course was the kerf test so I got the kerf measurement out of it as well and you can see the speeds there for each of these lasers and again from the lowest end to the highest end we're almost in order of magnitude faster the curve test there is this perception that small beams creates create little kerf and it's easy to argue that except that when you look at the results of say the the sculpt on s30 the kerf is relatively huge compared to all the rest and at the far end the the acmer P2 the the beam kerf was really 0.162 millimeters so it wasn't as terrible as people would like to believe and some of this you can tweak with Focus uh potentially sometimes the automatic Focus measurement that manufacturers use isn't exactly accurate but I used what they gave me and I came up with these numbers all right all the data has been compiled and it's in that table down below and I'll leave that table up while we're talking about the Miss as I'm trying to knock these down I'll start with this first one and it's this the real laser power that's reaching the material doesn't change a whole lot based on the size of the laser module now this one is bogus I don't know where this is coming from clearly people who who sell 10 watt lasers have some kind of an agenda to convince people that their 10 watt laser is as good as a 33 watt laser it's wrong and you can see it in the in the data here the energy density that we measured or calculated rather from a 5 watt laser through 10 20 33 goes up as you would expect so a 33 watt laser has roughly four times the energy density of a 5 watt laser you can also see The Cutting speed has improved greatly and the only reason it has improved is because the power has gone up a 33 watt laser is almost 10 times as fast cutting material as a 5 watt laser so you can see it it's true people have to stop talking about this all right myth number two which I've just brought up on the screen here is also one that disturbs me it's a bit harder to to disprove based on our data but I'll explain why it's not true and myth number two states this adding more diode lasers makes the beam size bigger and I don't know where this comes from there's this perception that there's some mystical power that's required to get all these diodes lined up inside the laser module we live in 2023 we have engineering that can generate accuracy down to the picometer so you know we don't have alignment problems with lasers but if you look in the data you can say hey this might be true if you look at the 5 watt it definitely has a smaller beam size than the than the 33 watt but we need to understand why that's true okay so to understand this I brought up this diagram and it's really A Tale of Two lasers the one on the left is a laser with a short focal length lens and the one on the right has a long focal length lens now you might wonder why you'd want to do this well if you look at the dark blue rectangle on each of these you can see that on the short focal length lens it's much smaller it's shorter it's narrower and on the on the one on the right the long focal length lens it's longer and wider now why why do we care about this well if you have a 5 watt laser there's not a lot of power there and we saw this from the energy density calculation it's about a quarter of what the 33 watt laser has so you really need to get that that package of light pinch down as as tightly as you can so you use a short focal length lens the side effect of that is the beam gets smaller that that actual spot size and you need that because you need to get all that energy pushed down into that tiny spot the downside is the beam doesn't cut is deep and we'll talk a bit more about that in in a future myth in a few minutes but with the longer lens we can we can use a 33 watt laser because with a with a high power laser you really want to get that that ability to cut deep so you need that longer lens to to get that length but the side effect there is the beam spot size gets bigger because the usable area of the beam is is wider and that's what's happening here it doesn't mean that the one with the big beam is worse or it certainly doesn't mean anything that that there's an alignment challenge with all these diodes it just means that we have different Optics now that discussion is a good segue to myth number three which is increased beam size somehow makes the output worse it makes the kerf bigger it does something well again that's not true you can see from the curve numbers here that the that the 5 watt laser with the single diode has a kerf that is almost a quarter of a millimeter whereas some of the other numbers here are much smaller including the 33 watt laser with that quote unquote huge beam size the kerf is actually smaller again we need to understand why well part of it is again because of that short lens the beam is much more conical as it's hitting the material so the kerf gets bigger it's just that simple Because the actual spot size of the focus might be 0.06 millimeter square but where it first hits that material or as it's digging down into the material when it's cutting it's creating a beveled Edge and that's why the kerf on a 5 watt laser could potentially be bigger or by contrast the longer narrower focus of the of the 33 watt laser means that the the sides of the cut are much more parallel and they're not perfect again because the lens is actually creating a cone but it's much more parallel than it certainly is for a 5 watt laser okay we're dispelling this like crazy here and we're at myth number four which is this one adding more diode lasers causes a loss of power this doesn't seem right to me I don't know about you but I have heard YouTube content creators say this exact thing and they are lying to you I don't know if they know they're lying maybe they just don't understand and the reason is again if you look in the table down below you will see that a 33 watt laser with six diodes in it versus a five watt diode with one diode has many many times the power the energy densities four times the speed can will go up so it's a lie now we need to understand why so what I did was I created another diagram here and this is a stack laser so there's four diodes working together to create what is going to be like a 20 watt laser in theory it's 24 Watts but you can see every time the beam hits some kind of reflector it's going to lose some of its power there will be some that just doesn't get reflected and the exception might be the very first mirror at the Top If that's a solid mirror we won't lose that four percent it will get 100 reflected or 99 point something but let's assume that we're going to lose some of that now when that beam hits the back of the next beam integration down that one is actually a translucent reflector it's got coating on one side on the inside of it to do the reflection for diode 2 but it allows the beam from the top to pass through but when it hits the glass there it's going to reflect a bit and it's going to lose some power and so on down the line now if you add all of these things up you'll find that it works out to uh we're going to lose about 16 percent probably which coincidentally works out to you know in the case of a four watt stack works out to about four Watts so that's where the power is going and you will lose you will lose some every time you pass through an optic again when we hit the lens some of the beam that hits the lens is going to be reflected all over the place so we're going to lose a little bit there on the way out as well so that's what's happening in the end you're not going to lose anywhere near the power you added by adding a next a second diode or a fourth diode in this case so you know the the the claim that the power will be reduced by adding diodes is a very dubious claim it's just not going to happen that way so we're at our fifth and final myth here and it's it's this one Higher Power lasers can cut deeper now certainly if you look at the agmar P2 review I did just recently and if you haven't seen it you can click up here that laser is a 33 watt laser it can cut a 29 and a half millimeter thick piece of acrylic that's amazing but the power isn't the only reason that's happening go back to the laser diagram I showed you earlier and I'll pop it back up here this laser uses a longer focal length lens and that means that the package of usable laser light for cutting is longer that means by definition it can cut deeper and that's the sole reason this is happening the 33 watts of power that's what enables it to cut acrylic in the first place it's the length of the lens that makes it cut deeper and it's physics it's not it's not a power thing it's just simple Optical physics and that should be enough to dispel this myth okay so there's five significant Mists that are dispelled and these are things that I've literally heard other YouTubers say if you continue to watch those channels and they say these things unsubscribe from those channels because they're either trying to lie to you or they don't know that they're lying to you which is maybe even worse subscribe to my channel I will always Endeavor to tell you the truth and the reason is because I don't guess I like data I like to measure things and here's the proof you saw a table you saw the test I did you can do these tests on your own and it's as simple as that now if you do want to understand material testing I'd suggest the next video you should watch is this one up above and get out there make your world and I'll see you next time

Channel: Steve Makes Everything

Views: 15,950

Keywords: Steve Makes Everything, atomstack, diode, diode laser, diode laser myths, engrave, engraving, laser, laser cutter, laser cutter projects, laser cutting, laser cutting machine, laser engraving, laser engraving machine, laser myths, laser projects, lightburn, xtool m1, laser range, laser measurements, laser evolution, laser performance, laser diode, laser experiments, laser testing, laser misconceptions, diode laser facts, laser power

Id: 4e-enyQeWEo

Length: 16min 18sec (978 seconds)

Published: Fri Sep 01 2023