RDWorks Learning Lab 22 The 50watt fraud a lesson learned

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  • Опубликовано: 2 ноя 2024

Комментарии • 56

  • @catweazle_1
    @catweazle_1 2 года назад +1

    I've seen and HEARED the first 30 seconds and I can't stop laughing.
    You're not only an expert in laser-technology, in teaching, and in scientific research, you're also very humorous.
    I have my 40W laser for two weeks and I am looking all your videos, beginning by lesson 1 and I'm enjoying every minute. I have learned yet a lot!
    Thank you very much for your videos!
    Stefan

  • @Virtualmix
    @Virtualmix 8 лет назад

    Thank you for sharing your discoveries with the world!
    I have a very similar machine and after a lot of testing have found that 60% was the most optimal power setting I could use for cutting 3mm acrylic. Now I understand why!

  • @VladOnEarth
    @VladOnEarth 6 лет назад +1

    Thank you so much for offering this awesome research for free for all of us!

  • @mikeselectricstuff
    @mikeselectricstuff 8 лет назад

    Fine for checking performance change over time, but why would you assume burn depth is linearly proportional to output power ?
    As you go deeper, you will get more smoke in the way, changing beam width and conduction away though the material is likely to be a nonlinear effect.

    • @SarbarMultimedia
      @SarbarMultimedia  8 лет назад

      As you get further into the series you will see more of the experimental work that I undertake and once I get a power meter I know for certain. Wood smoke is one thing that is a very efficient absorber of the 10.6 micron wavelength light and MUST be blown away with efficient air assist whereas acrylic cuts with a completely different mechanism and its cut is directly related to the energy density of the beam. The further away from the focus point the lower the energy density and the weaker the cut. Also please remember this is effectively a video record of my learning about the technology and trying to understand all the detail problems that many gloss over. I make mistakes as I go and that is all part of the learning process. I appear to be blazing a path that others are following. I just wish there were paths for me to follow when I started out 18 months ago. However, nom real complaints because its benn the best fun ever.
      Thanks for the comment
      Best regards
      Russ

    • @mehmetdtx
      @mehmetdtx 5 лет назад

      if the smoke was the primary factor, the degradation of performance (the depth of the cut) would be linear because the distance laser travels through smoke is expected to be linear, however that is not the case (see the 13:49).

  • @mehmetdtx
    @mehmetdtx 5 лет назад

    In the previous video, you mention you bought the new tube but have not installed. I am curious if it was installed before this experiment (for the sake of apple-to-apple comparison). Thanks!

  • @kward101
    @kward101 8 лет назад +2

    Haha, only a 20% BS ratio on the wattage, that's a pretty good truth to advertising ratio for Chinese electronics. Their LED light lumen output and NiMh battery Ah claims are often 50% or more BS. Wonder how the 50w Chinese compares to the 50w Epilog? An Epilog is just not in the budget for me now, but w/ the 60w option this Chinese laser is less than 1/3 the cost (US).
    Thanks for sharing all of your hard work. This is a really great resource you have created.

  • @Blueyedevil2702
    @Blueyedevil2702 4 года назад

    Thank you for clearing this up.
    I just purchased and received a few days ago a 5030 chinese laser and it came "equiped" with a KH laser (Kehui). From the first look I knew it to be bullshit, as it has some visible dust particles on the inside of the inner tube... Lucky for me I saw one other video from Thinklaser that warned me about the quiality being crap. I just hope that for a few months will be able to fire a laser beam, enough for me to make some money for a new tube.
    What do you think about CO2 tubes from CouldRay? I am planning to get one to replace the "original" one sooner or later.

    • @SarbarMultimedia
      @SarbarMultimedia  4 года назад +1

      Hi
      KH Laser tubes are usually repurposed EFR rejects Although at 40 watts ( which your 800 long tube will be) it may be from another brand.. One cannot say how much of a failure it was, maybe just failed or working but almost junk. Without an ammeter and a power meter you will never really know, An ammeter is peanuts to buy and very simple to fit and will be your tubes best friend ever!!.
      just put "ammeter 30mA" into an Amazon search for quickly available items, or do the same for ebay but get caught in possible delays from China.
      A 40 watt tube should not be run at more that 18mA.
      If you buy a CR45 tube from Cloudray, it will be an A grade SPT manufactured tube that has been relabeled by some local licensing agreement. It will deliver 50watts at 18mA because SPT are about the only company to UNDERSPECIFY their tubes. You will always get more than declared on the tin.
      If you watch ruclips.net/video/V_ehGE51rH4/видео.html you will see me fitting and testing a CR70 that deivers well over 80 watts and it's not even it its max allowable current.
      The important test to note is the one that I do at the beginning of the video where I make a 10 second burn with the unfocused beam into a block of acrylic. If you can get a couple of pieces of 5mm clear acrylic and superglue them together to replicate this test, it will tell you a great deal about the quality and performance potential of your tube. If its blunt it's rubbish and if it's pointed then it may be ok.
      Best wishes
      Russ

    • @Blueyedevil2702
      @Blueyedevil2702 4 года назад

      @@SarbarMultimedia Thank you so much for all the effort. You made my tube choice so much easier now. I already had exactly that type of tube in my Aliexpress basket (this is where I do most of my online shopping), but I wasn't sure about how good it is. Now I feel more relaxed. The only bad part is that the tube is about 200usd, and after import taxes in my country the price will end up aroun 260-270usd... Other than that, all good. I will test the laser this weekend and if it's really bad I will open a complain against the seller to get back the money for the tube (paid 1700usd for the entire machine and shipping).
      One more thing: can I use distilled water and car coolant (the pink type) to cool the tube? I have my machine in a pretty cold room and I'm afraid for the water not to freeze inside the tube and crack it.

  • @jessicatseng6734
    @jessicatseng6734 7 лет назад

    Thank you for these tutorials! They are fantastic. I'm thinking of purchasing (probably from the same company) a laser cutter fitted with a 100W tube. The thing is, I have my suspicions as to whether this is a good idea or not, because it looks as if the machine is not made to originally fit a 100W tube, so it looks like the manufacturers have just added a protruded casing in order to get the tube to fit. My question is whether this will somehow compromise the machine's functionality and if I could consider this a safe purchase?

    • @SarbarMultimedia
      @SarbarMultimedia  7 лет назад +1

      Hi Jessica
      From my experience, ALL ebay machines are fitted with B grade tubes that work but not very well and often not very long. The important thing to check is that the machine is fitted with 25mm molybdenum mirrors and at least an 18mm diameter lens. Size is important if you are using a 100 watt tube . Different tube manufacturers claim different beam sizes and 20mm mirrors may be ok for lower powers (50 watts and below), But above 60watts then the possibility of the beam having power out to 12mm does exist Any 100 watt tube claim is likely to be false. It will be quoting peak power which you cannot use or you will invalidate any warranty that may exist. It may well be a good quality Reci W2 tube for example Reci claim it is a 90 watt tube but if you stick to their recommended normal running current its in reality an expensive 80 watt tube. You will never get what is claimed. I would chose a machine bed size that suits your needs and accept the standard rubbish tube supplied (maybe 50 watts) When you have had a little experience with the machine you can upgrade with a "proper A grade tube and power supply to suit your power needs. A word of warning. Engraving requires almost no power whereas cutting is power hungry. If you buy a 100 watt tube you will find it VERY difficult to do some types of engraving or card cutting because you just do not have sufficient power control at the low watts. 60 watts is a reasonable compromise power combined with 1.5" and 2" focal length lenses. Look at the cost of 100 watt machines which may need a fairly quick tube replacement anyway as opposed to the right size frame that you can upgrade at a later stage.
      Hope this helps a little
      All best wishes
      Russ

    • @jessicatseng6734
      @jessicatseng6734 7 лет назад

      Thank you. That was very informative! I am taking your advice and am now considering a 60W machine with my desired bed size. I saw in one of your tutorials, where you switched between different sized lenses to run an experiment in determining cut depths, so that convinces me that I shouldn't have to worry about changing the nozzle or anything if I ever wish to change to a different sized lens. Is this also true for mirrors? Could I switch between different diameters without any problems?
      On a different note, I came across this post on a forum about a guy that purchased a Redsail X700 (one of those red-black ones) and he seemed to come across several big issues. In his post, he mentions that all the wiring in his machine was 22 gauge and that they were melting from day 1, so he had to rewire with an 18 gauge. Furthermore, the main power and 3 plugs at the back of this machine runs through the E-stop, which melted after only 1hour of running time. At first I thought that this machine and the one you own all came from the same manufacturer, therefore with the same quality standards, but now I think I might be wrong. Is your machine of better quality? Or is it just a stroke of luck that you didn't run into any of these issues? They are selling this machine for cheaper, but since I haven't seen your machine run into any of the same problems, I am definitely more inclined to spend a little more and get the same machine as you. I provided a link below to this forum in case you are interested:
      en.industryarena.com/forum/a-warning-about-redsail-x700-60w-machines-ebay-right-now--264142.html

    • @SarbarMultimedia
      @SarbarMultimedia  7 лет назад

      Hi Jessica
      There is a fairly simple explanation why these machines can fail in certain situations. They were originally designed in China for use in small Chinese businesses Just because they are shipped around the world now is not reason enough for them to change something that works....in their country. The problem is the world's electricity supplies divide into two camps.
      www.google.co.uk/imgres?imgurl=www.quantumbalancing.com/worldelectricity/images/voltages%2520around%2520the%2520world.gif&imgrefurl=www.quantumbalancing.com/worldelectricity/electricityif.htm&h=968&w=1347&tbnid=EId7rs7nVOLwLM:&tbnh=151&tbnw=210&usg=__sL_tNZ_eEJnJTuql_3Bt8TgW3jo=&vet=10ahUKEwiAs6q2zMjWAhUIZlAKHd-RD-oQ9QEILTAA..i&docid=JU6wFNGHPPl5JM&sa=X&ved=0ahUKEwiAs6q2zMjWAhUIZlAKHd-RD-oQ9QEILTAA
      Take a look at this map and you will see that about 2/3 of the world's population uses a 220/240 volt system and and mainly it's the Americas that have settled on using 110 volts.
      If you can remember back to your science lessons and Ohm,s law, one aspect of it was that watts (power)= voltage multiplied by current. In simple terms that's the problem being encountered here. Halve the voltage and the current has to double to get the same power output. Doubling the current means heating the wire to a point where it melts the insulation. The machines are designed for use at 220/240 volts where the current is 50% of that required for the same power output in a 110 volt circuit Copper wire is expensive and these machines are built cheap. I suggest they are not going to increase costs and compllcate stocking and distribution to satisfy the 110 volt market so all the mains wiring will be under rated and potentially dangerous
      You did not say where you were from but I suspect you are in a country with 110volt mains? I have two machines. One which is all Chinese and cheap but works ok because my mains electricity is 220/240 volts. Thus small wire will not overheat. My other machine is built in China but with UK design guidance to make sure it meets world standards. I cannot say which other machines ( apart from the really expensive Epilog, Trotec and Universal machines) meet this higher standard for mains wiring. It's less than 25% of the machine's wiring that is carrying mains voltages, thereafter it's all low voltage dc.
      I can see it is a problem for you. If you buy cheap then you need to have some level of electrical competence to check and rewire if necessary. If you buy from an import company that are just local distributors for standard Chinese machines, you cou;ld well be buying the same problem at a more expensive price. There are companies that import Chinese machines where they do insist that local wiring standards are met but you will pay an even bigger price for that insurance.
      Mirrors. Most machines will be supplied with 25mm diameter mirrors. This only becomes more important if you are using 60 watt tube and above.
      I hope th'a answered a few more of your questions
      All best wishes
      Russ

    • @markjenkins1569
      @markjenkins1569 4 года назад

      @@SarbarMultimedia Russ: I have a 50w Chinese machine here in the USA, running on 120VAC. No problem, as the total power requirements for the machine aren't really very much, and my 20A breaker in my garage never trips. All the internal parts for the US version are made for 120V input, with plenty of power to spare on a 20A service.

    • @SarbarMultimedia
      @SarbarMultimedia  4 года назад

      @@markjenkins1569
      Hi Mark
      You are right that the current draw from the machine itself is comfortably low and will run from a 120v supply. As you also rightly say, all the components inside the machine are either dual voltage/frequency compatible or have 120/240 switches. I get lots of correspondence from US users with 120 machine issues. The most common problem is melting the emergency stop switch.and a few with melted insulation on some wires. These machines are designed and tested in China where the supply is 220vac. Run them at 120ac and the current draw will be TWICE that which some parts of the machine were designed for. If you check the specification of the E/stop switch you will find that almost every one (certainly the one fitted to theses machines) has a 10A rating . That is fine for the machine itself but the problem begins when you start plugging ancillaries into the sockets at the back of the machine, such as the water and air pumps plus a fan. ALL of that addition load passes through the mains wiring and the E/stop switch ....oooops!!! So make sure you do not use those very convenient sockets, Run another multiway socket from one of your wall sockets and all will be safe.
      Best wishes
      Russ

  • @The_Unobtainium
    @The_Unobtainium 7 лет назад

    Thank you Russ for your work you share with us. I'm at the very beginning on the learning curve you've passed. Don't even have my own laser. I'm at the stage of deciding: buy K40 and play with it or play with making my own machine with more power laser. Haven't decided yet.
    But I have a question on the focused beam: is it possible to use more than one lens to form the laser beam. First (from the laser tube side) would be convex lens to focus wide beam coming from mirrors and the second one would be concave one to form the beam parallel again but much smaller diameter hence much more energy dense. I haven't seen that so far. Is it because the concave lens will be burnt in few seconds??
    Parallel, highly spotted beam would cut much better, deeper and with better edge quality. Isn't it?
    Now i back to the rest of your awesome videos!:)

    • @SarbarMultimedia
      @SarbarMultimedia  7 лет назад

      Hi
      I toyed with getting a K40 as a starter machine. Everything about it was limiting. Low power (30 watts max), no digital control system, no adjustable table, everything mounted on flimsy brackets, rubbish mirrors, minute working area, no air assist etc etc......... The next step up to a 300x500 50 watt machine may have been 3 times the price but it was a proper CNC machine that had real uses . I have really mixed feelings about what I bought because it was fitted with a crap tube and then I went out and bought a replacement crap tube. All part of the learning experience. I reflect and think that if that machine had been perfect out of the box, would I ever have embarked on this amazing learning journey. I am seriously glad I did not take the K40 route
      I have played with a 4" lens to reduce the beam size before it hits a 1.5" lens at the bottom of the lens tube. Did not get the result I expected!! Binned the idea. Not even promising.
      However there are dual focus lenses already existing see
      www.sintecoptronics.com/FocusingLensDualFocus.asp
      Sadly they are large diameter for industrial machines
      The problem with trying to be clever with lenses is the materials. The standard materials are zinc selenide and gallium arsenide. Both are only about 70 efficient at transmitting IR so they put an anti-reflective coating on the finished lens to bump that efficiency up to about 95%. There are VERY limited styles of lens in these materials, in fact I have only ever seen TWO, plano convex and meniscus. So your options to be creative may be seriously limited.
      Nice thought though
      Best wishes
      Russ.

  • @fibranijevidra
    @fibranijevidra 5 лет назад

    What a wonderfull test. Thank you Russ!

  • @hillelposner6658
    @hillelposner6658 9 лет назад

    Thank you for that awesome demonstration. May I ask why you removed the lens and didn't just run 10 colors at 10% intervals on the acrylic (with the lens on)?

    • @SarbarMultimedia
      @SarbarMultimedia  9 лет назад

      +Hillel Posner
      Hi Hillel
      I think I understand your question to ask why I didn't set 10 colour layers in my program and just run it?
      Lens removal---- Ideally I would have liked to test the mode burn directly out of the tube at the back of the machine. I'm not only looking for depth of penetration but also the shape of the burn. The conical burn means that there is more power at the centre of the beam and the shape of the cone is an good indication of the power distribution within the beam. It is difficult to position the block at the back of the machine and not all machines have space for a thickish block. I therefore thought it would be easier for others to replicate if I worked at the front of the machine. Now bear in mind that the laser is a collimated beam ie it comes out of the laser tube at about 6mm diameter and remains at 6mm diameter right up to the lens where it gets reduced to about 0.1mm diameter at the focus point. I am trying to see the power distribution across the beam and not the focusing efficiency of the lens. I hope that answers your first question.
      10 colours----- The whole principle of this program is to run the burn for an accurate fixed period on each %. Sadly I could not find a way of programming the machine to stand still (???? in answering your question FLASH OF INSPIRATION!!!) the slowest I could run was 1mm/sec, so I devised the moving platform approach to keep the block positioned statically under the head. After every test I had to stop to reposition the block and thus I had lots of time to edit my % power parameter.
      However. your question has prompted a ????!!!! moment. How can I get the machine to stand still whilst running a program? Answer, UNPLUG THE Y AXIS MOTOR. Now I can write a multi % program with pause periods to reposition the block under a STATIC head.
      Looks like I'll have to revisit this mode burn test to simplify it. Thanks for your input.

    • @hillelposner6658
      @hillelposner6658 9 лет назад +1

      Thank you very much! I've been lasering for many years but never investigated the ma / power relationship or thought to look at how linear the power line was. You demonstrated that really nicely. My new laser has a MA meter and now I know what to look for. Thanks again.

    • @epkuva
      @epkuva 8 лет назад

      +SarbarMultimedia How about removing the cable from Y axis and let the machine to move on X axis. This way you don't need to put your hands in there with the potential burn.

    • @mehmetdtx
      @mehmetdtx 5 лет назад

      pauses between cuts would be achieved via horizontal lines with 1% power and slow speeds - if the slowest speed was not enough then come back a little :)

  • @geast67
    @geast67 6 лет назад

    I was wondering, did you check in the menu FILE->VENDOR SETTINGS in the LASER tab what is the maximum laser power?

    • @SarbarMultimedia
      @SarbarMultimedia  6 лет назад +2

      Hi
      The vendor settings have nothing to do with this problem. I am now 3 years older and wiser and later verified that I was supplied with a tube that was rejected by one of the large manufacturers as not meeting specification and as sold for scrap. A third party took these tubes and retested them to make sure that they worked "in some way", enough to fool any naive E bay buyer, and sold them on cheaply but for a huge profit!!!! If you see a tube labeled KH Laser then this is just such a tube. The values in the vendor settings are all to do with protecting the tube from being over driven. They are expressed as % power and not watts. It is likeley that ANY tube you buy from Ebay or Amazon market place could be such a B grade tube so do your homework on who is selling it. The % power used on these machines is very misleading. because it is a % measure of the HV power supply output. Look at the max output mA on the HV power supply label and THAT is 100% and is a the current used to stimulate the lasing action. There is NO linear relationship between this current and the watts output.
      Best wishes
      Russ

    • @geast67
      @geast67 6 лет назад

      I had the same issue with a RECI 80W lamp, brand new. It has a label on it saying agreed power 75W, and max power 80W. Well my measurements where 65.4W direct at the output of the lamp. The vendors settings laser power where 90% and i put it to 99%, just to test the output and the ps was regulated to give just 20mA. After i adjust it to 28mA the power went to 77,4W.

    • @SarbarMultimedia
      @SarbarMultimedia  6 лет назад +1

      Reci is a greatly over rated product (in my opinion). I have experienced 6 different Reci tubes (4 x W2, 1 x W4 and 1x W6). None has impressed me. You are paying a lot for the name and, as such, the high value of this product attracts the fakers. Reci have worked on those problem and any genuine tube has a Q code that you can scan and verify it's pedigree.
      see www.recilaser.com/en/index.php?m=&c=Index&a=show&catid=13&id=34
      The lowest Reci tube is the W1 rated at 80 watts see here www.recilaser.com/en/index.php?m=&c=Index&a=show&catid=7&id=65
      2. Operation conditions
      Water cooling: using purified water; 2 to 5 liter/minute; water temperature: 10℃-40℃.
      The operating environment: temperature 2-40℃; Humidity 10-60%.
      The working current: test current is 29mA. Maximum working current is 29mA. The running current must be kept below 27mA. The life span can reach 8,000 hours if the current is kept below 25mA.
      Let me put this Reci double speak into something simple............ We tested this tube at 29mA and it delivered 100 watts. Never exceed this current. When in use, the current must not exceed 27mA (80 watts) or you will invalidate the warranty. HOWEVER, if you want a half decent life out of this tube we suggest you limit the max current to 25mA (maybe 70 watts??)
      None of your numbers are anywhere near this spec....hence my suspicion.
      Best wishes
      Russ

  • @mehmetdtx
    @mehmetdtx 5 лет назад

    i am curious how the output wattage measured in the chart at the beginning: 1:00. If I had to guess one would measure the voltage and the current across the laser tube and multiply the two, but cannot be sure.

    • @SarbarMultimedia
      @SarbarMultimedia  5 лет назад

      I was very naive at this point in my learning journey and I assumed I had bought a 50 watt tube. and this data was comparative . How wrong I was. This was a junk tube that barely output 30 watts when I eventually bought a rather expensive power meter to measure actual watts. DO NOT go anywhere near that red wire to measure voltage. Its 25 to 30,000 volts DC and can kill you.. Trust me there is no direct way to measure watts output from the tube with ohms law. The link between power in and power out is lost in some very non-linear physics. Very crudely the 25Kv ionizes the nitrogen in the the gas mix and that is the pink beam you can see. That nitrogen can then carry current flow. The HV power supply responds to your request for %power and controls the current flowing through the tube..More current flow means hotter and higher energy levels in the nitrogen. . When the nitrogen atoms collide with the CO2 molecules, there is a physics reaction that eventually creates photons of light that get amplified by mirrors within the laser tube. That INVISIBLE IR light exits the tube and is the laser beam.. There is no way to measure the power in that light beam except allowing it to react with a surface to convert the energy into heat.. you may wish to jump to the following videos for how the tube works and how you measure power
      ruclips.net/video/2F5O-1TH8b0/видео.html
      ruclips.net/video/lO9rWlobLZU/видео.html
      Best wishes
      Russ

    • @mehmetdtx
      @mehmetdtx 5 лет назад

      Thank you for the explanation and the videos in general. Today was my first day testing my machine and after 5-6 cuts I came across your videos on power loss. Had I not, I would end up with the same destiny!

    • @SarbarMultimedia
      @SarbarMultimedia  5 лет назад

      @@mehmetdtx
      Hi Mehmet.
      Mine was slow journey but yours can be speeded up by watching all the mistakes I made along the way,
      Good luck
      Russ

  • @mattimhiyasmith
    @mattimhiyasmith 7 лет назад

    What's the ramp up time for the PSU? possibly it takes more than 6 seconds to ramp up.

    • @SarbarMultimedia
      @SarbarMultimedia  7 лет назад +1

      Hi Matt
      Remember that this series of videos is a record of my learning journey with this machine and technology. At this stage I knew there was something very wrong with the machine but had not yet acquired the knowledge to understand what it was.. The story unfolds as the series progresses If you wish to jump to the last page of this murder mystery
      ruclips.net/video/J0KEg5X6wlA/видео.html
      You will find me discovering exactly how the beam is being controlled and in a related episode I establish that it takes between 3 to 5ms for the power supply to ramp up, depending on the power its aiming for. A little different to your 6 second guiess??? But hey, I'm 18 months further into this project now and a LOT wiser.
      Best wishes
      Russ

  • @SarbarMultimedia
    @SarbarMultimedia  5 лет назад +2

    Hi You must remember when watching these videos that you are on a learning journey with me. I obviously know a lot more now some 3 years on. At the time I was struggling to ascertain if I had been ripped off by the Chinese. I now know absolutely what the scam is. At this point I had no idea how the tube physics worked and I had no means of measuring the power. A little later after I had bought another tube from Ebay (and got ripped off for a second time) I invested in a proper power meter. as what you see in this video was my best estimate of the rubbish I had bought.
    see
    ruclips.net/video/DrbQdIAQl4s/видео.html
    ruclips.net/video/lO9rWlobLZU/видео.html
    Best wishes
    Russ

  • @kellyleek9
    @kellyleek9 9 лет назад

    you think the the problem is from the laser tube or the power supply that feed the laser?

    • @SarbarMultimedia
      @SarbarMultimedia  9 лет назад +1

      +nayef al
      I do not have any absolute way of measuring the power from my new tube, my results are all relative, but as you can see clearly from the mode burn results, using in excess of 60% power will not get me better results. My new 50 watt tube was sold with a specification of 20mA recommended drive current. it is possible that my power supply gives out 20mA at 60% power setting and I am actually getting 50watts of output. This could mean that it was probably set to over-drive my original tube, and with me doing a lot of testing at 95%, I quickly wrecked my tube. As I have said to all those that look at my videos, I am still learning, but sharing with you my current knowledge and insights. This over-driving is a new issue to me and I am still learning. Depending on how your tube power supply has been set, it may be safe to run at 80% or more. There are many machine users out there who want to just use their machine and not be concerned about these sorts of technicalities. This video is just a warning to all, BE CAREFUL, and shows them an empirical method of finding what a safe percentage may be for their particular machine.
      I have recently joined a user group where there is a discussion on this point.
      www.sawmillcreek.org/showthread.php?209026-My-LASER-current-meter-for-DC-tubes
      I am planning to build one of the current meters mentioned here to monitor my tube current. I am a little hesitant because I am not an electrical engineer and the thought of messing with 20,000 volts DC needs a bit more research into the cable requirements to feed the meter and the housing insulation. Until I experiment (or get some tech help) I don't know if I dare adjust the power supply or whether I shall just keep an eye on the meter.

  • @DIYMindset
    @DIYMindset 8 лет назад +1

    How deep was the cut in mm with 60%?

    • @SarbarMultimedia
      @SarbarMultimedia  8 лет назад +2

      After a year I can still find the test block.... and the answer is about 8mm. I was using a 1.5inch lens and the diameter at the mouth of the cone was only 5mm. If you follow this series further you will find real power data for this tube after I decided to purchase a power meter and was able to plot the REAL power characteristic of my tube
      Best regards
      Russ

  • @mehmetdtx
    @mehmetdtx 5 лет назад

    I think the primary reason depth not increasing after 60% is most probably the loss of the focus. A better experiment could be to reduce the time, say 1 second.
    EDIT: I did a similar experiment with mine (2nd day of using). With even 20% power it made it through the other side of a 13 mm acrylic in 6 seconds. And the cuts were very thin, which makes me think that your machine was not focusing properly to begin with because yours were starting out big, which should not be the case given the manufacturers resolution specification.
    To be exactly specific, here is the design of my experiment which should be equivalent to yours: put 8 vertical bars 1 mm tall spaced 15 mm apart. assign each bar powers from 10 to 80 percent, 0.166 mm/sec speed, and 10000 miliseconds of opening delay (choose through mode with 1% power, otherwise opening delay is ignored).
    On a second experiment, I increased the speed to 1 mm/second, thus staying on each bar for exactly 1 second. In this case, 20% power barely made it to 13 mm, but 30% made it through.

    • @SarbarMultimedia
      @SarbarMultimedia  5 лет назад

      Hi Mehmet
      My previous answer my help with this also.
      Best wishes
      Russ

  • @freebird1963
    @freebird1963 7 лет назад

    If my 40 watt tube tests 34W max then I shoudln't run it at no more than 20.4 mA then ? My K 40 has ampmeter not percent meter. Thanks.

    • @SarbarMultimedia
      @SarbarMultimedia  7 лет назад +1

      Despite claiming to be a 40 watt tube, yours will be 700mm long and in truth capable of 35 watts max/ That means a limiting current of 17mA. If it was an 800mm long 40 watt tube them 18mA would be the limit. 20mA is for 1000mm long 50 watt tubes.
      An ammeter is a the only way to know what is happening to your tube. Your tube is full of a gas mix and all those gasses are naturally non-conductors. However if you subject nitrogen (one of those gasses) to a very high dc voltage, it starts to break down by a process called ionization. In an ionized state, that non-conducting gas all of a sudden acts like a piece of wire and can carry huge current flows. You cannot allow this to happen so you need to regulate that current. That current varies the energy level in the nitrogen which in turn is the driver for the lasing action.. So power is not regulating the laser beam directly. In fact when your tube is dead ie run out of CO2, there will still be a pinky/white beam in the tube. The engine is still working but the wheels have fallen off!!
      Best regards
      Russ

    • @freebird1963
      @freebird1963 7 лет назад

      Thanks.

    • @fibranijevidra
      @fibranijevidra 5 лет назад

      @@SarbarMultimedia Hey Russ, is that length/amp relation valid for all co2 tubes or just for those chinese made?

    • @SarbarMultimedia
      @SarbarMultimedia  5 лет назад +1

      @@fibranijevidra
      Hi
      In general there is a simple rule to follow. Do NOT overdrive your tube. These are max values that you should abide by. if your tube is 40watts (18mA), 50watts (20mA) 56 watts (22mA) 80 watts (24mA) 100 watts (26mA)
      To understand why these values are so important take a look at
      ruclips.net/video/2F5O-1TH8b0/видео.html
      Best wishes
      Russ

  • @samsonmira9302
    @samsonmira9302 3 года назад

    To me this like you testing the mode adjustment this has to be sharp cone shaped

    • @SarbarMultimedia
      @SarbarMultimedia  3 года назад

      Yes, you are correct, it should be a sharp cone and this is hardly a cow pat. At this time 6 years ago I believed that power was the key ingredient and that this tube certainly had no power. To prove this beyond doubt I had to buy a power meter (later episodes)., However more recently I have been able to understand the relationship between power and intensity and that it is possible to have power without much intensity.
      Best wishes
      Russ

  • @avcomth
    @avcomth 4 года назад

    This video is old and outdated but still have its merits. Ali sellers still sell their 40 watts units as 50 watts but nowadays you simply chooses machines with "protrusion" chambers because 50 watts tubes are longer than 40 watts. It is very easy to corner the lying sellers before making the transactions.

  • @EdBonds
    @EdBonds 9 лет назад

    Brilliant...ordering acrylic next along with bouncy castle fan!

    • @SarbarMultimedia
      @SarbarMultimedia  9 лет назад

      +Ed Bond
      Oh dear....I hope I'm not going to cause a "run" on bouncy castle fans and cause prices to sky-rocket!!

  • @hydraulicsystems332
    @hydraulicsystems332 7 лет назад

    What is the program at 3:24 called?

    • @SarbarMultimedia
      @SarbarMultimedia  7 лет назад +1

      The program is RDEWorks and it is specifically written for the Ruida digital controller. You can download a copy free from
      en.rd-acs.com/down_complex.aspx?FId=n14:14:14&pageindex=2
      Best regards
      Russ

    • @hydraulicsystems332
      @hydraulicsystems332 7 лет назад

      Thanks

  • @RandomPsychic
    @RandomPsychic 5 лет назад

    Damn your generation's women and their "to do" lists...