RDWorks Learning Lab 109 Joining the dots Part 4

[@conlinepilot]

I feel there aren't enough "thank you's" posted on your videos, I have spent countless hours watching and learning and have enjoyed every single minute. Thank you, and please keep up your very excellent work.

[@MxT333]

YOU ARE A BOSS in my books! Keep up the good work!

[@Runner50783]

I was talking with a friend the other day and I was recalling all of the useful things I've learned from your videos, I think with out them I would not have purchase a laser cutter and if I still did it would have been hell. So thanks for all of the work you put into these series. Can't wait until you get to other subjects like servo reponse time and tuning.

[@BrilliantDesignOnline]

All through this vid, I appreciate the description of the steps and hypotheses and evaluations and paper drawn parameters. I think the very first 150 dpi was really the best for contrast, darkness and detail, but perhaps deceptive from viewing it in the video. Learned a lot. And the Brittney photo was easy on the eyes for the sake of seeing it many times; my condolences on her letting you go.

[@SarbarMultimedia]

Her loss not mine ( says a man with adented ego!!!!) I have learnt so much more about laser and graphics in the past 4 years Here are a couple of videos you may wish to watch The first one mentions the titanium dioxide Norton process fir which ther is another video . This first video is an examole od 254ppi image kzbin.info/www/bejne/baGppopnr7Weock and this one using a white tile and TiO2 manages to achieve 508ppi kzbin.info/www/bejne/iofKnqKEZtyfoNU Those original principles still apply. Best wishes Russ

[@mikeboehk2307]

Hello Russ, Awesome videos and methods on understanding how the laser works and forms dots. I never thought I'd learn so much in just 4 "short" videos. I didn't even need a cup of coffee. I just hope when I retire I maintain my passion for learning as you clearly have. Mike

[@SarbarMultimedia]

Hi Mike I have to admit that did not know what I was going to discover upon entering this dotty world. It has opened up possible explanations for other observations I have made and may have wrongly attributed to other causes. Lots more learning to do but we shall hopefully gradually uncover the "whole truth" Glad you found it as fascinating as I did. All best wishes Russ

[@MarkPlas]

Hello Russ, I justed wanted to post a very big thank you for sharing all this research and information. Keep up your valuable work, it is so much appreciated!!

[@momagaragepcmods6194]

Hi Russ! Thanks for lots of great videos. Very interesting your videos. I have a laser machine that I just bought. Your videos are helping me alot. Please stay that way. thank you so much. From Japan.

[@SarbarMultimedia]

Hi Fabio Thanks for the kind words. Even after 2 years of exploring this technology I feel that there is so much more to discover and understand. It is a hobby and not a full time job so it great to learn at a steady pace. There are so many unexplored corners to these little Chinese machines I'm sure I will have to get them to ultimately bury the machine with me when I "go" All best wishes Russ

[@tekknorat]

Stereoscopic image at 35:23. You, Sir, are a God of lasers. Highly valuable information.

[@PeterEduard]

Nice video Russ! Thorough as always. I am not convinced this is the end of that subject tho. I am ready to watch a revisited a couple of months from now. ;)

[@SarbarMultimedia]

Hi Peter You are so right. This deals with the core understanding of the dotting problem and there should be enough of an understanding now for me (and others) to go in ever widening circles of discovery.. I can see some fascinating possibilities for using this process as a finishing process for 3D engraving if I cannot get the results I want directly form grey scale. I have yet to play with glass and acrylic to see just what additional factors you need to understand All best wishes Russ

[@fy2880]

Thanks for the video, Russ. I would appreciate it if you would please clarify a bit more about the Scanning(Reverse interval) function. You did an adjustment for 400 speed. By inputting an adjustment for 400 speed, will that only affect scans done at 400, correct? In other words, if you don't set up a reverse interval for a particular speed, you will not get any correction for that speed? If this is true, have you found the required interval adjustment to vary significantly for different speeds? You did reverse/change back the previous change settings you had made for backlash, correct? I am guessing you did but wanted to confirm. When do you use the backlash correction function that you used before vs. this scanning (reverse interval) function? The first one is just intended to be used for vector cutting problems? Thanks!

[@SarbarMultimedia]

Hi These sessions have revealed so much to me and still left a few questions unanswered. You are right in that the reverse interval only works for a matching speed. That is why there were several speeds already in my table. It is also a bit more confusing for me because I have to keep changing those settings depending on which one of my two machines I use. If you go back to the beginning of the video where I set that reverse interval and look carefully at the lines, you will see that near the end of the line there is a small narrowing then the beam wobble to a stop. I am suspecting that the narrowing is the actual point of beam switch off and the rest of the cut is occurring as the beam decay is taking place. The faster the speed the longer that fixed delay will drag out. Thus when you decrease the speed the offset get less. That's just a logical supposition based on the way I could see beam decay delay on my pixel tests. The cnc control system is very impressive and I'm 100% sure that this reverse interval is niot any sort of stepper response "fix" but definitely all to do with the switching response of the beam on and off Yes I did remove the original backlash setting and I would assume that it is there to fix mechanical issues. However, I have never had the need to use it because if they are mechanical issues then they will be fixable by mechanical means ie belt tensions loose fixing screws, misaligned bearings causing drag etc etc Hope that answers your questions. Best regards Russ

[@evanwinn372]

Hi Russ, Is there a video where you explain reverse interval. I'm not clear on what that does.

[@SarbarMultimedia]

Hi Evan When the controller sends a signal for the tube to switch on it does not INSTANTLY deliver power There are delays in the power supply and within the physics happening inside the tube There will also be some delays at switch off before the power decays. When I scan left to right there will be an delay in the scan line starting and finishing. When I scan right to left the same delay will occur but in the opposite direction. So in this video you see the offset between the scan lines due to those delays. When you run slowly (up to maybe 100mm/s say) you will not notice the delay . The delay is a constant, so as you scan faster the head travels further before the beam comes on or goes off. You can account for this fixed delay with the reverse interval offset. With scanning you tend to use typically say 100/200/300/400mm/s. For each SPECIFIC scan speed you use you must add a correction factor. The alternative is to scan in one direction only (X unilateralism) but of course this will double the run time. Hope that answers your question Best wishes Russ

[@evanwinn372]

Thanks so much. Is there a formula to figuring out the interval or just trial and error?

[@SarbarMultimedia]

Hi Evan Sadly no formula unless you know exactly what the delay time is on your HV power supply. It's trial and error but only takes a few trials for each speed to get pretty close. It will never be perfect because the delay has minute variation Best wishes Russ

[@steven-jellemeijer8412]

We see clear line effects, would one persive them if the image is tilted 15 degrees counterclock just as newspapers do? could be usefull for 3d"carving" aswel.

[@SarbarMultimedia]

Hi Steven First, thanks for the comment. I did not know about the 15 degree dither skew. That's an interesting thought. Sadly RDWorks only allows 90 rotations of bit maps or it gets confused. I will try importing a 15 degree skewed dither from Photoshop, but I suspect RDWorks will work its magic and resample back to 90 degrees . It will be an interesting experiment. I also anticipate that it will not fix my vertical lines. Although not an exact footprint of the stepper motor's 200 native steps, I believe that it is the non-uniform motion of the stepper that is driving resonance at certain running speeds. That is a subject I will soon be investigating, so your suggestion is very relevant. Best wishes Russ

[@steven-jellemeijer8412]

Hi Russ, Thats a fast respons. (im having vacation from lab-technician job, that does include a FABlab so i can respond fast aswel.) If RDWorks does rework it to 90 deg. just put in the material on an angle. This wont fix real data output, it is just that we are more prone to interpret horizontal and vertical lines more strongly than lines that are off axes. Good luck!

[@SarbarMultimedia]

Hi Steven. In Photoshop, rotating the image automatically does what I anticipated RDWorks would do and keeps the pixel orientation horizontal by resampling, even though the picture is rotating. However I think that will do the trick. If I now engrave my image rotated at 15 degrees the pixels and lines will be horizontal until I rotate the picture to upright for viewing. Worth a try. Thanks Russ

[@Thinklaser]

Hi Russ, Did you use the 1.5" lens or the Standard 2" lens for these tests? Fantastic results / video again. Gareth

[@SarbarMultimedia]

Hi Gareth I used my special 1.5" lens on the Lightblade machine rather than the China Blue for these tests because I had seen that the Lightblade had a much faster responding HV power supply. I was attempting to get the best conditions possible for my experiments. Best regards Russ

[@Runner50783]

What I've learned is that it all depends on what you are engraving. If I'm engraving solid figures, say text on acrilic or rubber stamps, you want the highest resolution possible, because that "sausage" effect is great for removing material with surgical precision. When engraving pictures, its a whole different story, there you want the most accurate pixel to burnts (burned dots :)), in that case something like 150 PPI and 150 burnts is probably enough.

[@SarbarMultimedia]

Hi Abraham I did answer this comment a couple of days ago but note that when I look today the answer has disappeared. Did it ever get to you? Best regards Russ

[@Runner50783]

Hello Russ, I did not

[@SarbarMultimedia]

Hi Abraham Let's try again. That sausage effect is a bit strange because I think you can see it having a real effect when I did my little REVERSE INTERVAL test square. As I have discovered, the faster you run the longer the sausage. Well, if you look carefully at the tail end of my test lines you will see a little narrowing just before the line ends. I believe that is the point of beam switch off and the rest of the line is due to beam decay delay. That reverse interval delay has nothing to do with correcting any errors with the CNC sysytem, which is unbelievably accurate and spot on for such a cheap system. It's all to do with fixing the beam off delay which is a constant and thus appears to get shorter as the speed decreases. I'll be interested in finding out more how you are exploiting this zone of uncertainty. The other interesting comment you slipped in was about the "highest resolution" for engraving text and solid figures(logos?) Perhaps i am misinterpreting that but If you create your text in a bitmap program such as Corel then your solid black text will always be a series of dots (or sausages depending on how fast you run). My solid black pixel test demonstrated that EVERY pixel has its own pulse, so sausage dots are producing multiple burns. However, if you work with vector outline text (or objects) then you will be scanning with simple on/off beam uniform line burns. With just this beam off aberration, that I described above. I would have expected cleaner results from this second method. I know you have done a lot more work on this subject than I have, so any feedback information you can contribute will help me greatly. All best wishes Russ

[@Runner50783]

Yes, I've got to say I'm utterly impress by the RUIDA controller, the amount of technology packed on such cheap and compact system nothing but incredible, It may lack native support for closeloop feedback but its as good as it gets for this kind of systems. I think I'm misreading you, what I call sausage effect is the continuous overlapping of lasing dots, that overlapping is supperb when I'm engraving letter press plates for instance. I go as low as 0.02 mm to get the sharpest characters possible without aliasing, aliasing is fairly noticeable when I do 0.06 mm or higher, 0.04 mm is good enough. I'm currently exploring what are the true limits of my system, I've been able to engrave with presicion up to 1200 mm/s, I've not gone any higher because I'm affraid my machine will collapse, I'm buying a new linear rail system that should work better at high speeds and accelerations (look MJUNIT or CCM). But I still do not know what are the actual limitis of the laser tube response time, so far it seems even at 1200 mm/s there is still room to go.

[@s9500vip]

Hi Russ : I've encountered an interesting problem which was “engeaving time” . For example , when I want to engrave a 10x10 cm plywood object , I set the scan speed to 300 mm/s ,30% power and the gap is 0.05 , scan mode : x_swing , the machine calculates it's process time is aproximately 11 minutes . So , when I do the job of 3x3 cm , I still use the same configuration ,the process time is about 1 minute and 30 seconds . What happend to me was when I tried lower speed like 100 mm/s , it only took me 1 minute , when I tried faster speed like 500 mm/s it took 2 minutes and 10 seconds , was this amazing ? I spent some time to figure it : if it was the acceleration cause the small object needs lower speed to achive least process time ? Is there any kind of formula to konw when to use the proper speed to scan different size of objects to get the minimum process time ? Best Regards Ryan Wood

[@SarbarMultimedia]

Hi Ryan I am just about to leave for a two week break away from my machines. Now I do know that there are other places within RDWorks where process times are calculated and I'm told ,quite accurately. However, you will need to have pc and machine connected. I have not explored or tested this and obviously I shall be unable to do so for the next couple of weeks. It may be under the Doc tab. Best regards Russ

[@dimitrichaava5995]

@sabarmultimedia hi, I'm am currently in process of buying a laser from china- i was suggested bodor 1309 (150w) can you please advice if this one is good quality product? Is there anything better in china? Thanks, Dimitri

[@SarbarMultimedia]

Hi Dimitri. My experience was with one particular Bodor machine when I was helping a guy in Florida. I found the engineering on the machine to be to a high standard when compared to ebay machines. However I was disappointed by the way they had provided that desktop machine with a 100 watt reci W2 tube that was just far too big for the design of the machine.. These are Swiss designed machines that look very pretty, but being built in China by folks that do not appear to understand the technology they are dealing with was a bit worrying. Several other of my correspondents have bought Bodor machines. Some have been trouble-free and other have had issues. These are not at the cheap end of the market and if you wish to know more directly from a guy that bought two mid size machines (like you are considering) I can connect you if you message me your email. Whereabouts are you? Apart from spending lots of money on something like a Trotec or an Epilog machine, buying from China is still a risk. Usually you get a reasonable trouble-free machine that will have support from the factory BUT any technical issues that you encounter will be very difficult to resolve because of the language barriers. Their use of English translation to understand technical problems and explain solutions can be like speaking to someone from another planet. Here in the UK I deal with Thinklaser who have set up a very good model. It is similar to the Bodor concept but much better managed. They have been heavily involved with a Chinese manufacturer and influenced the design of the machines, the selection of quality components and specifically they have designed the electrical wiring and interlock system to proper European machine tool build specifications. This was necessary for proper CE approval and because they wanted to sell these machines into industry, schools and colleges. They are really nicely engineered Chinese-built machines that leave China built to a high quality standard. Just remember that all Apple products are made in China and no one ever questions their quality.. Buying through an agent who will help you obviously makes the machine more expensive but there will be someone who is accountable. 150 watts is a lot of power. What do you want to do with the machine? You need power to cut and very little power to engrave. The problem with trying to engrave with a high power tube is that you will find it very difficult to get low power control. That is one of the main reasons why they have twin laser machines. 150 watts for cutting and 40 watts for engraving. The best compromise is around 60 or 70 watts but it does depend on your needs. Bigger may not always be better. Would you use a racing car for going to the shops? Best regards for now Russ

[@dimitrichaava5995]

SarbarMultimedia hi Russ, thanks for your time. Russ, basically I need it for cutting 6mm plywood in large quantities. I was suggested stronger laser for better result. I am buying it from the official website so i guess its better. I had a check on bodor piranha (uk) but they are twice the price. I will send you my email as PM. Thanks for help. Dimitri

[@pamelalopez9187]

i am having such a hard time with my machine was wondering if i can ask for some advice. thank you

[@SarbarMultimedia]

Hi Pamela Check your you tube messages Best regards Russ

[@pamelalopez9187]

i am ok with the basics. I just cant get the right settings to cut wood. It is taking me over 3 hours to cut one name. I can only get my hands on 1/4" wood at the local home depot, Its so much thinner than the wood piece you had cut a while back

[@SarbarMultimedia]

Hi Pamela Several important questions. What is the focal length of your lens ("2"probably)? What gap between your work and the end of your nozzle? Do you have a little screw control valve controlling your air assist? What length is your tube and what is the claimed power output? Are your mirrors clean and well aligned? Is your lens clean? Are you cutting on a honeycomb bed or is your work raised off the bed? As you can see there are lots of factors that could be affecting your cutting ability and one final question. If it's solid wood, what type is it or is it plywood? Best regards Russ ps have you watched kzbin.info/www/bejne/hXS5pICOrJusnpY

[@mikaelludwigsson]

Thank you for all videos I am learning a lot from! Maybe you can tell me how you get the laserhead move so fast! 250 mm/s is the fastest I can run with my 100W chineese laser. Over that the head will loose its position.

[@SarbarMultimedia]

Hi Mikael Take a look at your You Tube messages Best wishes Russ

[@swp466]

18:28 It looks like you've transposed a couple digits for your example drawing. You showed the dot matrix spacing as 0.1963mm when it should actually be 0.1693mm.

[@SarbarMultimedia]

Hi Steve You obviously watched it properly and spotted my , I could say "deliberate mistake" You are the first BUT I would be lying. It's the incompetence of age. When you get to this stage of having only two grey cells left, you would think that less would be easier to manage. You have seen the fallacy of this logic. Thanks for pointing it out. My list of age related ailments is growing....., old, fat, grey, ugly and now incompetent Lots of smiles Russ

[@swp466]

LOL -- your reply put a smile on my face. Age notwithstanding, I'm in awe in your degree of knowledge and breaking down every detail of your "retirement hobby". I'm just about to pull the trigger on this "hobby", and have found your channel and videos quite informative. I'm about to order a Boss LS-1630, and have been binge watching your videos since I found your channel. There seems to be a general lack of good quality informative channels for lasers on KZbin, and your channel does a good job of filling that gap. Keep up the good work, and don't stop slipping in "deliberate mistakes". It keeps viewers on their toes ;) The KZbin channel "pocket83" slips "Easter eggs" in each of his videos, and you really have to be quick to stop on the single frame to see what it is. Deliberate or not, you handled it like a champ! Cheers!

[@iantard5065]

Hi Russ. great information as allways. A quick request, when you do these very detailed videos could you please, either in the narrative or comments provide your benchmark wattages for the % powers you use in the video. We can then replicate on our machines which are as diverse as it comes. Awesome work. Regards. Ian Jenkins

[@SarbarMultimedia]

Hi Ian I'm now on vacation and tried to get this video done before I left. I had recently put a new tube into the Lightblade and have not yet had a chance to characterize it so I do not know what the %power to watts is at present. It is still a 60 watt tube and it "feels" about the same as the previous one. I will do a characterization and put watts into the description in future. Thanks for the reminder Russ

[@DoRC]

I think the thing is that everyone will just have to experiment based on their material, subject and printer. There are soooo many factors there cant possibly be one answer to fit all or even most.

[@SarbarMultimedia]

Hi You are so right. If you read my answer to Peter it says it all. I have done nothing more than reveal that there is a lot more to engraving than meets the eye. Best regards Russ

[@mea1230]

Russ! I just love your videos. I can watch them all day long. Have you heard about living hinge? If its interesting enough to you, I hope you cam make some videos in the near future. keep it up, you have one of the best channels in this field.

[@SarbarMultimedia]

Hi Thanks for the kind words. Yes the living hinge is something I know of but not yet experimented with. I have so many things lined up to explore and do with my machines that I think that project may be several months away....but it's not forgotten Best regards Russ

[@homebeerbrewery]

Great video, thanks for sharing! Cheers

[@pacejs15]

Someone should make a Website- where all Laser enthusiasts will share their thoughts, videos and will advice each other. It'll be a good stuff I guess... ps Russ, you always...pleasure to watch Greeting from Latvia

[@SarbarMultimedia]

Hi AP There are already at least two that I know of www.rdworkslab.com and facebook.com/groups/900528680076062/ Best wishes Russ

[@RichardRocket1]

Hey...look at it this way...you are a lot younger than dirt! Have not cleaned the mirrors yet...it is about 110 degrees in the garage now...summer is here...

[@bindasmeme3168]

sir please one tutorial video for perfect and clear image engraving on transparent acrylic (image edit to rd work setting)

[@SarbarMultimedia]

I do have plans for a session on photo engraving on acrylic and also on glass. Because acrylic damages so easily it is difficult to get very small dots I have a range of meniscus lenses on their way from China and will be experimenting in the near future. Thanks for the interest Russ

[@caroweyers7005]

Thank you 😊

[@SarbarMultimedia]

Hi This was just the start of my learning journey into photo engraving. There are many more videos to see and the subject has forced my into areas of understaning about lenses and laser beams that few others have explored. % years on and I an still trying to understand why the HV power supply response time has o a limiting effecton engraving speed. Take a look at this video as it may be informative .kzbin.info/www/bejne/oKjSapuoi82jf9k and here is a very shot video to show what is possible at the extreme kzbin.info/www/bejne/iofKnqKEZtyfoNU Best wishes Russ

[@robxsiq7744]

47 minutes..right...well, I guess I know what my morning will be focused on then. neat butterfly. acrylic?

[@SarbarMultimedia]

With your persuasive nature I'm sure you could get Danny to add a front porch swing!! ps Cast not laser cut (yet)

[@robxsiq7744]

Pfft. Danny has exiled me to the warehouse for weeks now ...no air conditioning... ...Florida. Avenge me!

[@gonzaloshark]

eres master. voy a tener que estudiar ingles para enterderte bien. ....saludos.

[@zarbi123456]

Thank you sir.. Where can I find your email??

[@SarbarMultimedia]

Hi You can either contact me via the forum rdworkslab.com or add your disguised email address (johndotsmithatgmaildotcom) to another comment and I will reply. Best wishes Russ

[@normcaissie5598]

Does my GF know you are using her photo?

[@SarbarMultimedia]

Beware , she leaves when the money runs out!!!