Cutting Matrix
Vložit
- čas přidán 23. 11. 2023
- Cutting with a diode or CO2 laser is a very misunderstood subject. Yes, it is very easy to set a few parameters and make your laser do wonderful things and there are many videos advising the cutting martix to be the complete answer to finding those optimal cuttting parameters. This video demonstrates the inherent weakness of blindly trusting what appears to be a simple exploratory tool. Cutting is a very complex subject and I explains some of the basic issues that a new user will encounter Unfortunately , diode laser users will never be able to "see" many of these issues because the technology of the laser head is inaccessable for exploration. Additionally, the diode wavelength limits the materials available to aid exploration.
ps I know that 22/32is about2/3 but my mouth said 1/3....I blame the gap between my two remaining grey cells. - Věda a technologie
I just say that I think this is one of the best channel on CZcams. Of course very specific topic but gosh… educational and so much good advices and things to think about!
Most laser user are like my wife and her car. She knows just enough about it to get to the supermarket etc. Hand brake turns, the limit of adhesion , aqua planing etc etc will never be understood or explored.. My aim has always been to explore the complete envelope of possibilities for a laser machine (of any type) to take people beyond blindly fiddling with a few parameter seetings because an expert Lightburn user does not mean an expert laser user. Little details like the colour of the cut can be so meaningful, so it is observation of thiese small important details that I am trying to encourage . Questionining why about such observations will help push your understanding of the technology towards that envelope limit.
Absolutely and I have high respect of people exploring the full boundaries of a given system and work toward becoming an expert (which is a never ending life project). You get plus points if you can hack a system or said differently do something new which was not initially meant to be done with it
Outstanding. A must watch by anyone that uses a laser.
Great content your knowledge is ineeded far the best ive sseen.very impressive and educational many thanks.
Russ, I have a library of bookmarks that I share with many, many laser users on the various Facebook Groups that I monitor. Most of them point to your RDWorks Learning Lab Series. The bookmark I just collected for this Video has jumped to the top of this list. You covered (albeit, some of them briefly) so many things in this particular video that will be of use to many, and I will continue to leverage your knowledge to help others.
Thank you for all your efforts and most importantly, sharing your results with us.
Thanks for the feedback and for passing on facts about this wonderful laser tecnology. There is a sister video about using the matrix for engraving that you may not have
czcams.com/video/Na5_6okUyKg/video.html
My latest Myths and Misunderstandings videos are a collection of facts that I have gathered over the years but in different Lab episodes . Concentrating them into a concise format, I try to blow away the technobabble that machine sellers use in their videos when they have no idea about the science that underpins the technology they sell. I discovered a classic example of this Thunderlaser Odin RF machine video recently.. They were claiming the old message that short focus lenses create better quality engravings but the video evidence demonstrates exactly the opposite. Sad because I greatly admire the engineering and quality of the TL products. I know exactly why the facts did not fit the belief but speaking to big companies is a waste when I can tell the populus directly and they can prove the facts for themselves.
2024 will be quite exciting because so many people are now using laser diodes as a way into laser technology.. I have watched many videos and the inertia of ignorance is snowballing. I plan to create my own diode laser machine by fitting various brand heads to my RF machine. All diode laser runn off GRBL controllers but mine will be a normal Ruida controller that allows me to play with the PWM frequency, something that most diodes cannot access. Lots to discover and demonstrate
Russ, around about a month ago I wanted to ask you some questions and you sent me a link where I could ask those questions. I've been busy and never really got around to asking. Tonight I sit here watching and a big grin comes across my mug because you have just answered the questions I was going to ask. The first question was why my laser wouldn't burn below 10 mm/sec. I have known about beam drag for quite a while as you have discussed it before. I don't use the "test grids" anymore because of the problems you pointed out in this video. To be quite honest I have been using the SWAG method for setting speed and power on my machine with pretty good results. To test I normally use some scrap material and run the actual file and see how close I am and tweek from there. The method has served me well. Engraving photos is a different story. I use your method on that. Thanks for answering all my questions I didn't ask you. As always, a great video.
SWAG only works if you have proir knowledge and experience, thus new users are forced to rely on the advice of others and those others may or may not be experienced, who can say?
Hence the massive rush to matrix testing as the panacea for understanding your new machine.
I'm glad you didnt ask the 10mm/s question because a few weeks ago I was ignorant. However I had to think hard about the relationship of min power to Start Speed START SPEED is such a vague term that I would never have realised it actually meant. It certainly does not mean the speed below which the tube will fire because I regularly run at 1 or 0.5mm/s to cut 15 and 20mm acrylic (as I demonstrate in the video). No, the subtle fact is that min power is tied to this parameter. I was puzzled initially about my test squares at 49:30.. It makes sense that 0% min power is tied to that Start Speed parameter so that as you lower it, the start point for 0% power also resets. It seems that my tube is not working below 10% power. but I know that is not true. It does work below 10% but the power dops off quickly and requires a lot more EXPOSURE time to exceed the damage threshold for birch plywood. Thus at 400mm/s ( my drawing speed) there is insufficent power to mark the wood, my tube has not actually switched off. However here is an interesting brain teaser for you. Now that I have decreased my Start Speed to 2mm/s . and run my 400mm/s 25mm sqare at 65% and 2% power. I see no difference in the corner gaps and it still requires 10% min power to get the corners to just close.. I was expecting something different.
@@SarbarMultimedia No doubt I have learned a lot from you in the past four or five years so my SWAG's are pretty good to start with. I pay attention to things like the colour of the cut, how much carbon comes off on your thumb when you rub against the cut, and if it cuts all the way through with no fuzzies. If you understand the corollation between speed and power you can get there pretty quick and I have you to thank for that. Your journey in chasing invisible energy had given me insight that I otherwise would not have had I just bought a machine, put it together and then said, "Duh, what do I do now?" I have seen people that have done that and it shows.
By the way, when I cleaned my lens I turned it so the flat side is up. It made a big difference in the way it cut and engraved.
im working on 8 machines 1600x1000mm with 150w co2 laser on acrilic every day from 7 years .... i see you point .... but you see the manufacturer settings ... is about accelerating and decelerating ... and on my machines and software it treats circles and arcs diferent in speed parameters ... over the years i learn and understand so much from you .... THANKS
Great work - well done!
Extremely useful and easy tool
I think this particular video made my head spin just a little bit more than some of the others.. but! I have to say it did answer a question or two... I have always questioned the manufacturer's specified focal length and recently after doing a test or two I started to realize that a manufacturer's suggested focal point did not always give me the deepest cut.. I have always been so worried about the smallest kerf I never took into consideration depth into the wood and going from 1/8 in up to quarter inch makes a huge difference in Cut performance.. looks like it's back to more testing thank you for all the videos
Yes needs a few re watches as a lot of information here.
I have tried to cram as many basic ideas about cutting as possible into this session but to be honest I am only scratcing the surface of all the complex issues that go to make cutting happen.. My best friend (clear acrylic ) has allowed me to decode the cutting mechanism in the same way that an aircrash investigator tries to work out why a plane crash occured. Acrylic has unique properties that tell me about light intensity within the beam that must have been there to cause the damage. As an example of this that no one will have noticed,
stop the video at 55:27 and examine the tube that I burnt through the acrylic block. First question is why is the damage the not an expanding cone as predicted by lens theory? It's not, so something else is going on but what? Look at the shape changes in the tube and also the texture and straightness of the tube. Every part of that image tells you what is happening. It a bit like reading Egyptian hieroglyphics.....easy when you know.
At 55:30 you're showing the beam dragging in the acrylic and are mentioning 2 potential factors, one of them being the reflective material that bends the light beam and your video appears to actually prove that theory as well. You start the explanation with a stationary shot, which traveled straight down. After that you move the laser to the right while firing at the same power. You do not move the laser to the left but in the acrylic you can actually see the bend cross the straight line that you created before and creating a distortion to the left of the first shot.
When you then look at 25% speed at the 56:39 shot it appears that the beam at first follows its previous curve (tries to go around the corner as you call it), until it has reached enough energy to melt the previous bend after which it goes straight down. You mention that is basically possible in the laws of physics and there now appears to be video evidence of it :)
At 10.6 microns wavelength the only materials that truly reflect are metals of all types. and if this was a metal curve then yes reflection would take place. Howver, acrylic has unique properties that show the path if the damaging light intensity.. T very low incidence angles ther is a small percentage of reflected energ that I have verified in previous tests but thismeffect id rapidly overcome by the light beams natural stright line path.. If you examine the intial burn "pipe" that I produced there are some interesting characteristics to observe. First, accordingto everything you know about focused lightbeams what happens after the focal point (which was set at the surface of the acrylic) should be an expanding cone. How thereforeis it possible to creater a nearly parallel tube through 15mm of acrylic? Note also the pattern about 10mm deep where the tube balloons in a strange non-straight way before eventually following the initial straight line to exit the bottom of the material.. I'll leave you with that puzzle to ponder Optical theory is fine but all theories have to have boundaries for them to apply and I have discovered with many such practical experiments that lens theory cannot apply to predicting damage to materials with laser beams, there are too many inconvenient variables just take two simple demonstartions I made where the damage to the same material with the same parameters is different at front and rear of the machine . Also the supposed same wood tested in the same part of the machine gave different results.
I appreciate it when people such as yourself spend time studying the data I provide and maybe arrive at a different conclusion. I hope it will encourage them to devise their own experiments to validate (orotherwise) their own observations.. Thanks for the comment.
Another great lecture video, I think you have to rename your channel to "Laser University". Why aren't cut tests done with a 100mm long line? then just hold up to a light to see if there was a cut? I think I'll try that.
Would adding a small radius to the corners give a cleaner cut or a worse cut? Or will it just require more setup? Thanks.
The thought is logically correct because I have been designing metal laser cut parts for years and the standard practice is to add a small fillet radius to all corners. However. in this instance our machines are nowhere near as sophisicated as the monster 10 to 20kW machines so we have to think differently. If you imagine putting a 5mm fillet on each corner then thereare no longer any straights, you create 10mm circle. Did the 10 mm circle give me believable parameters?
Hi Russ..
Can we use light burn for ruida controller??
All Ruida controllers are driven by their own free software called RDWorks. However, it is a bit clunky and "old school" in its user interface........ but, for free, it's a great piece of software that does the job. About 6 yeras ago, an enterprising young software writer ( a keen laser user) decided to use his skills to reverse engineer the RDWorks software into a much more powerful and modern software that he called Lightburn..It is now lightyears beyond the original RDWorks offering. So fear not, Lightburn works with ANY Ruida controller. In addition, it also runs on Linux and OS as well as WIndows. If you go to the Lightburn website you will see that it can drive MANY other types of digital and G code based control systems as well as RF CO2 machines, fibre lasers and diode lasers. It is truly now becoming a universal piece of software that is rapidly becoming an industry standard. You can download and test the fuull version for 30 days free. I cannot recommend it too highly
@@SarbarMultimedia wow nice info
Thank you :)
Hello, I have an OMTECH 60w laser and want to buy a 4” lens but don’t know how to find the focal point. Please could you help me?
Hi Chris
It all depends on the type of lens tube and nozzle fitted to your machine as to whether you can usefully use (or even fit) a 4" lens. Various videos and sales literature I have looked for your machine are fitted with various types of lens tube. My best guess is that you have a lens tube with a 16.3mm outside diameter, in which case it will be impossible to even fit a 4" lens The nozzle hole is equally limiting.
This is a typical cheap Chinese head which was ideally suited to early 40watt machines. The bore ofm the lens tube will be about 11 or 12mm diameter whoich is not really big enough to take a 50 watt laser beam. I say 50 watts because your tube will be 50mm diameter and about 1000mm long Yes it has a max TEST power of 60watts but the normal running wattage will be limited to 50 watts at 20mA.........and that's if its a good A grade tube (most are not)
You can contact me privately via this contact form and we can exchange pictures etc and work out a possible solution when I see your set up.
forms.zohopublic.eu/ndeavorlimited/form/K40XtreeemLaserCutterContactRussSadler/formperma/k2Cn0QN5ChpazfTMAUw25lZ-FKpjZa96TQWHjv3ntOg
Best wishes Russ
Good morning Rus, I am writing to you from Seville, Spain. I have a small problem with my laser and RDworks. I have bought a new Windows 11 PC and have installed RDworks. The problem I have is the following. In order for there to be communication with the laser with USB, I have to disable memory privacy in Windows 11. If I enable it, communication with the laser with USB disappears, since it tells me that the drivers are obsolete.
I have installed more recent versions of RDworks and the problem is getting worse. Can you help me solve this problem. I can currently burn and cut, but my PC's security is vulnerable with kernel integrity disabled. Thank you
Hi Manuel
I am usually stuck in the past with my PC systems and at present I run Win10 and Win 7 with no issues. However I have recently bought a Win11 laptop but not yet installed RDWorks . So I have no first hand experience to share . However I would advise that you download the FREE 30 day trial of LIghtburn because that was built around RDWorks but is now way ahead with usability, and features. II feel sure you will not encounter the same issues and if there are problems there is a vast Lightburn forum to solve your problem. I also use Lightburn but have not yet transferred my licence to the Win11 pc.
Best wishes
Russ
Thank you very much Russ for his prompt response. Currently I am very familiar with RDworks and all of its configurations provided by you (burn patterns, line spacing patterns, focus step meter, etc.) I am a little afraid of changing software. I'm still waiting for those tests with Win11 with Lightburn jejejejeje. Thank you as always for your contribution. Greetings Manuel@@SarbarMultimedia
Lightburn creates circles with many small segments. A 10mm circle has 65 lines of gcode. With an 8-bit GRBL controller you run out of gcode processing speed. I run into this processing speed limit before baud rate limit, or mechanism limit, or laser power limit.
Hi Steve
The circle that Lightburn creates is a proper CAD element with no facets. Zoom in on a circle and you will see no discrete lines. It exports a DXF file as a perfect circle with a centrepoint as its control element. I suspect the flats you detect is a requirement of the GRBL controller that knows nothing about circles but has to create an aproximation of any curve with short lines. That poses an interesting question....... does EVERY line have its own acceleration and deceleration? That would give really weird results. Thus much better to draw lines for cut testing.
The lightburn Gcode sets the start of the circle , the feedrate and the laser power. Then a series of G1 lines with X and Y coordinate are sent to complete the circle. The laser is turned off at the end with and S0 and then an M5. I am beginning to see some of the weakness of the GRBL controller. @@SarbarMultimedia
GRBL was for 3D printers that use STL files, and as STLs are triangles didn't really need GCode arcs. IIRC GRBL converts arcs (G02, G03) to shorts lines, but there's a setting that determines how many lines it creates ie how smooth you want it to be. LightBurn should be sending arcs, not lines.
This is not an issue with GRBL, as GRBL does accept G2/G3 commands for circles. You can verify this by sending those commands on the "console" tab in lightburn.
The problem is that lightburn doesn't use G2/G3 for arcs when parsing to gcode, and instead it aproximates the curve by a series of G1 commands. You can verify by drawing a circle and saving the gcode, then analyzing the codes. It is all G1's, no G2/G3.
That being said, I never overflowed a 8bit AtMega2560 with G1 aproximated arcs, so I'm not sure what happened to your controller. Were you using a Uno?
What do you think the highest achievable DPI is for black granite stone?
That's quite difficult to answer because it depends on your machine beam size, the lens you are using and how you set your machine to achieve a specific size of dot. The principle achieving a known size of dot is the key to defining the DPI you can run at. Understanding digital graphics and dithering is also an essential knowledgee area.
Granite is strange because it is not a single material but the flecks you see are two distict materials with different damage properties. One is quartz and the other is feldspar. Yes it will engrave but the image will be blotchy. You may be able to achieve 254 DPI at very best but please watch these two videos to understanf the issues you will encounter and then use the little bitmap test to find what your machine ncan achieve that is in the text description of part 2
czcams.com/video/jl6OYf3nJfA/video.html
and
czcams.com/video/j6eaUroujXg/video.html
Good luck
@@SarbarMultimedia I'm using a 60w reci laser tube and a compound lens set from Cloudray. I used the bitmap test but the bottom row of dots seems to be a single line
A few questions.
1. Does all material use the same focus height?
2. If so, is there a "best" material suited for finding the focus height? Like you said, the granite can burn unevenly at times because of the different elements.
hI
Are you aware of the preiomnization mode for operating your tube? Reci tubes are particularly bad at operating in this zone. Usually the zone is between about 10 and 15% power but Reci seem to produce a ring burn at those powers rather than a small dot. The ring does not fill in and become a dot until maybe 20 to 25%. I have experience many Reci tubes of various powers and this seems a common characteristic and makes it pretty useless for creating small dots. 60watts seem very low even for a for a W1 tube which is rated at 75 wtts normal power at 22mA and is supposed to have a max factory tested power of 90 watts. Take a look at the graph on your tube . If it didn't reach 90 watts then this is a factorty reject tube that has failed to make the grade and will not carry a factory warranty. It will have been sold VERY cheaply to a local machine builder who will make much of the fact that your machine is fitted withn a Reci tube..........who but a few skeptical knowing individuals like me know what is really going on.? Have you done a mode bun on your tube to see what the beam intensity distribution is like? See czcams.com/video/naPzFsuvURU/video.html
Watch this video from about 24 minutes to help you identify the preionization zone for your machine
czcams.com/video/nZuatc3eIgU/video.html
@@SarbarMultimedia so it seems like I've been had. I have a dual tube machine. The W1's max power is 81.70W and the W6's max power is 147.0W. Are these trash? What tube would you recommend for engraving on a machine that has a bed size of 1600mm x 1000mm? I was told anything lower power than the W1 would struggle due to the bed size.
Hi
The w6 should have reached a max of 160 watts at final test.. It is raterd at normal power use of 130 watts with 28mA current flow. . These are not trash, just substandard.. The most important items within the tube are the 2 mirrors (one at each end of the tube ) that reflect the photons back and forth to createthewatts you use. If thes mirrors are just a fracion off perfect alignment, the power output drops. The only way to test the mirrors is by setting an expected power output for a given current. Typically that will be about 2mA above the normal running current. At that max current the output should still be increasing. If it peaks at a lower current and the power drops off as the current increases then it is a sure sign of small manufacturing fault. There is no way to fix the problem, the tube cannot be warrented. Instead, these B grade tubes are sold cheaply (rather than scrap them) to local machine builders and they also appeat in internet websites with no indication that they are rejects.. Reci are not alone in this practice and with all the data clearly shown on the tube its sharp practice on the part of the seller rather than Reci being dishonest (sort of). The intensity profile within the beam will be a bit compromised but and it could well be that the beam size and divergence are way off specification also. These tubes are not trash, but they will not be top performers . Your W6 may well claim to deliver the rated 130 watts and it will probably do so You may find that it works best with a 2.5 or 4" lens. However the compromised W1 tube may never be able to produce the small dots you are aiming for.. Study the preionzation video I sent and try to identify the range of %power before you move abvve the preionization zone. That lower zone will be your best chance of creating small dots., maybe at a speed of between 200 and 400mm/s. You cannot beat yourself up because tubes are very technical items and few hobbyists or small business users have the ability to know what defines a top quality tube. Instead you are trusting the vendor to deliver what he advertizes. Its fairly certain that the vendor will have fitted "jack of all trades" 2" focal,length lenses to your machine. You may be well advised to try the two longer focal lengths as they may collect and concentrate your beam power better.. For your W1 tube you can use cheap brown Chinese lenses (limited to 80mwatts) but the W6 will need the more expensive bright yellow lenses (rated at over 200 watts). This laser technology is akin to shark infested waters. End user naiv ety is the fact that sellers rely upon.. I have been such a naive victinm in my early days
So really the lightburn test square would be better if it just did horizontal lines first all the way across and then did the same vertically, That way it would not be slowing down to turn (only on the outside of the whole grid) and most squares would be perfect.
Hmm... yes the idea is logically perfect but then I'll leave you to write the program. Remeber that EVERY discrete CUT line will require acceleration and deceleration. It is different for scan line because the acceleration and deceleration happens during the overrun at the end of each scan line. The scan line itself runs at the prorammed speed.
I wrote some code that did that for performance (speed) reasons. I was cutting paper and laser cutters really don't like to do 90 degree turns at high speeds - you get squiggly lines as the head bounces on the belt. So yeah, all the verticals, then the horizontals and finally the rest. What I was cutting wasn't complicated.
hi, i know this is a bit off topic from this session but i wanted to share something with you. How a Lens Creates an Image (video) from chanel Huygens Optics... i hope that you find this video as educational as i did
Thanks for the reference. Yes it is a facinating expalnation of how light works if you treat it as waves. The whole of lens theory is based upon the principle that light photons are random and that light itself is of uniform intensity when it hits a lens. Laser light is not uniform and we are not trying to transmit an image . Instead, we are trying to concentrate the light to a focal point where in theory the massive intensity concentration is used to damage material. However if that theory of optics was true then stop this video at 55:27 and explain why the hole I burnt (with the focal point at the surface of the material) is not an expanding cone. Optical theory is fine for images but it cannot describe the damage that laser light INTENSITY creates. There are so many factors involved when it comes to cutting a material. Our laser machines (at least the CO2 machines) only have two lens forms to work with.......... plano-convex and meniscus. Both are created with simple spherical geometry in the same way that lenses have been made for hundreds of years. Unfortunately the shape come with physics weaknesses..... a property called sperical aberration... For image optics this can be rather disasterous and different lens shapes are usually combined to correct this problem in telescopes and cameras etc (image devices). However, it is the aberration weakness of a lens that gets exploited by a laser beam to creat the cutting action .On and off, I spent three years on my RDWorks Learning Lab channel decoding the mechanism of cuttin with a laser beam. You may be interested in viewing a few of those.
Note . The two off axis intensity spikes demonstrated by the wave theroy are only there because the light intensity is uniform. The fact that the non-uniform outer part of a laser beam is almost at zero intensity means you will not see this interference effect. Hmmm.... not entirely true. If you put a CO2 beam at full power and fire it at a target for long enough (maybe 30 seconds or more) these outer scorch rings will appear........but very faintly. They have nothing to do with cutting which happens in a 2 to 10ms time frame.