RDWorks Learning Lab 79 Machine Health Check Part1
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- čas přidán 24. 07. 2024
- If you own a Chinese laser cutter this little series of videos about me learning how to use the free software provided, may solve the problem of trying to learn from a virtually unreadable manual.
I am nothing to do with RD Works, I am not an instructor and I am no expert. This series will document the essential bits of many hours of trial and error - Věda a technologie
Russ , you are a godsend. Thanks for your patient meticulous analysis.
Hi Guy
At my age it's likely to be for my own benefit if my 2 remaining grey cells go on holiday/vacation!!!
Thanks for the kind words
Russ
Glad I watched this video... I have been running one of theses for a couple years and was thinking about buying a tube for a spare. I'll use my power meter and keep a check on my tube for now... Thanks!
Hi Ben
This information was from an "insider " in China so I'm now collecting data on tubes to see just how valid this "fact" is. Two years is a good period and I shall be happy if my 4000hour tube gets anywhere near that. Is your tube a good quality Reci or EFR? what wattage and dimensions?
Thanks
Best regards
Russ
Amazing info again. Thanks Russ :) Keep up the good work!
Absolutely great and important Video. Thank you so much !!!
Russ, would there be a way to add one of those red or green visible pointer lasers along side of the real laser beam so you can see a beam going through the airway? I notice when you are doing these test, you have your hand inside the machine and I always worry that there is the possibility to accidentally forget that the beam is there.
Hi Russ...
Thank you for another splendid video. ;-)
At 20:39 you flick the mirror in the light, and in a split-second I could see that you have SERIOUS scratches in the mirror surface.
That's for sure one of your power-loss problems, and your descision about buying new copper mirrors for your machine will give you great value for money.
When you clean your copper-mirrors, your best freind is acetic acid and acetone. First clean with acetic acid using a cotton-pad, then clean with acetone by dragging a lens-tissue along the surface.
(see the How To section on RDWorks Lab Forum)
-Pepsi-
Russ,
thank you for that video.
I'd like to say some words on the use of masking tape to check laser alignment:
I found out that the glue on the back of the tape immediately spoils the surface of the mirror or lens close to it.
There is some sort of oil film from the evaporated glue on the optical elements. Even if the laser is fired at very low power and short duration.
Since I noticed that I try to use small pieces of acrylic for the same purpose, but I'm still looking for some better material.
Concerning the lasertube lifetime I guess there are two effects combined.
1st) the diffusion of gas (namely helium) through the seals and even through the glass walls out of the tube.
This is a very slow but steady process, which takes years to render a tube useless.
I have a He/Ne laser tube lying around for 30 years now, which is still working fine.
2nd) the destruction of the gas mix during operation.
Compared to the diffusion this process is pretty fast and depends on the power the tube is forced to deliver.
Overdriving the tube of course accelerates the destruction of the gas mix significantly, but also "normal" operation
and even more operation at very low power ages the gas.
Every ignition of the tube shortens it's life.
So running a tube at very low power (which does a constat repeated ignition thousands of times per second!) is not very healthy to it.
The tube will reach it's maximum lifespan when operated just above the point where the beam stabilizes.
Lothar
Hi Lothar
Thanks for sharing your experience. Nothing beats that.I have explored this so called "high impact engraving"region at low current just before the tube fires up fully, and realized that it contains some very high currents (maybe 50 or 60 mA) at a frequency of about 3,5KHz. I use this region a lot for cutting card because it does a superb scorch-free cut. However, I have reasoned that I am accelerating the demise of my tube because these "over-driving" current values, although of short duration, are plenty long enough to cause dissociation. I also figured out that tube has to pass through this phase (albeit rapidly) every time the tube ignites. For most people this is the fact that will degrade the tube. The shelf life =tube life is something I learned recently from an "inside China" contact. As I said on my video, I am not surprised because even the best tube makers offer a very short warranty period . However, I am still open minded about what happens and when. I am told to not expect any significant power drop off until the CO2 has depleted to some critical level. Performance then drops of rapidly
I use my tube intermittently so it should have an easy ride as far as dissociation but its a 4000hour tube that has already "lived" 7000 hours and is showing little sign of failing. I shall keep monitoring and reporting from time to time.
Thanks again for your valuable input
Best regards
Russ
Hi love your videos, where do did you buy your power meter, I really need one of those.
Russ my Laser quit working the tube is not putting out a beam, how can I test it ?How can I tell if it is the tube or the power supply there is a green light on . There is three red lights on the motherboard 9-14-15 , the 14 is flashing. Can you help me. thank you Richard
I wonder how they actually calculate the hours. Most electronics are MTBF which is basically an average but it might be different.
Thanks for the response I have a problem which is the laser beam when engraving on the rubber has a volatile spark and the depth of the inscription is not good
Hi Anas
Rubber produces fumes that contains flammable products. If your laser power is too high, the power of the beam will be absorbed by the fumes and make them ignite. If you reduce the power and make sure you have lots of air assist you will get better results . You may have to run over the job twice to get the depth of cut or slow down the speed to get the depth of cut with the reduced power. Are you using the ramp engraving option?
Best regards
Russ
I love the long-term tube analysis. looking forward to the results.
Hi
How is your 60 watt tube performing? I'm now collecting any data available to see how true this "fact" is.
Thanks
Russ
unfortunately I don't use my laser very much and I don't have a power meter to measure the output with. I guess my tube would be a good candidate to test the life of a tube that is mostly dormant if I had a power meter.
Where do you suggest I get a new tube from?
Thanks Russ another good video. Did you ever consider, when you bought the laser, that learning its intricacies, and the complexities of RDWorks, would turn into a CZcams series?
Hi James
This started out as an entirely SELFISH project. A retirement activity that combined my love of engineering and my video hobby. Although I had previously run my own metal cutting laser business for 10 years with two 3kw machines, this technology with sealed laser tubes was COMPLETELY different and I quickly realized that the learning journey I was faced with was also a great material for my other hobby. At my age, family weddings, kids parties and exciting holidays have almost ceased and now I find myself attending more funerals (definitely not video material). I was just an old guy in his man cave having the most fun ever!! I mainly loaded stuff to CZcams initially as a way of trying to make old colleagues (who were still working) jealous.
I think that backfired somewhat. After a handful of enthusiastic nerds who might watch occasionally, who else would be interested???? . I have been staggered at the following and interest from all over the world. In this last year I have so many heart warming reactions, it is really beyond belief. However. I still plod on with my random and bumbling adventures of discovery. Despite many suggestions and requests for subjects, I am still selfishly following my own nose to things that interest me. The upside is that I have so many really good contacts now (and holiday offers (I think they want free tutorials or a service visit!!!) but the downside is spending a couple of hours a day pumping the keyboard.....it would be so rude to not reply to questions and comments
Best regards
Russ
"I am still selfishly following my own nose to things that interest me." Well said Russ, I find myself. in EXACTLY the same mode............keep active Bro............
Great video. I apologize in advance if this question has already been asked and answered, but what are you using to measure laser output power? I might be interested in acquiring one if they're within my budget. Thanks and keep up the great work!
Hi Tom
Most low cost basic power meters are in the $250 to $350 price range.
www.cloudraylaser.com/collections/laser-power-meter
www.macken.com/collections/analog-power-probes
You may be tempted by the low cost of this Chinese origin instrument. It was my first foray into power measurment and was such poor quality I gained a refund and bought a Macken meter. Some buyers have been happy (lucky?) and some correspondents repeated my experience.
www.2laser.com/laser_power_meter_probe_and_laser_monitor
It was for cost reasons that I and several other enthusiasts from various disciplines attempted to find a low cost way of measuring power. We all experimented with many wacky ideas but eventually I had to accept that square wheels would not be a good idea, despite their one redeeming feature, no handbrake required. I settled down to studying the conventional technology to see just where the high cost was occurring.
Please watch the following video before making a decision.
czcams.com/video/lO9rWlobLZU/video.html
Best wishes
Russ
Thank you! For your efforts to explain your "Laser Cutter" in every detail. I saw several videos for you and they getting better and better. Thank you for doing this, I appreciate this online help...
Is there any chance you have encountered a failure to read from the udisk port.Everything was fine until I deleted the files I was testing and the machine will no longer read from any u disk .I've tried several and reloaded the files to no avail. It says no file found.Guy
Hi Guy
Several possibilities
First the filing system on your USB stick MUST be FAT32.
Deleteing files is perfectly allowable and will not cause the problem you describe. I have several file transfer sticks and they all throw up this error from time to time. It's often a bad contact in the USB socket. I acually have an extension cable hanging off my USB socket for just that reason. At least I can easily change the USB cable.
If you have a USB extension cable plug that directly into the controller and I suspect that will fix the problem
Good luck
Best regards
Russ
You warned us that the would be a need for contortions when checking the mirrors at the front of the machine, but you must be aware that the rail at the front of the cabinet is easily removed by undoing the clips at each end giving much clearer access.
Thanks What do you mean Are you using the ramp engraving option?
Hi Anas
When you use scan mode there are 5 tick boxes below the power settings. One of those is Ramp Effect
if you tick this it allows you to specify a ramp size. If you are making rubber stamps this is important to support your thin sections.
see my video
czcams.com/video/cVuYyfJmfTs/video.html
Best regards
Russ
Thank you very much for all this effort. Please, is there an application or device that translates English into Arabic to take advantage of your excellent explanation of the valuable information you are presenting
I am sorry that I don't think I can help. I have searched to see if Google do a you tube translation into subtitles. They do so for English but not for other languages.
Thanks for your kind words
Russ
in the 7,50 minut from this vidio what the distance between the first class & the tube
Hi Anas
The answer is that it's not important. The laser beam can be assumed as almost parallel, so that distance will not affect the performance in any way. The main limitation for that gap will be whether your tube hits the casing at the high voltage end . You really need about 12 to 15mm air gap beyond your tube. so this may decide the gap between the tube and mirror 1. I like to leave about 40mm so that I have room for power measurement with my little probe.
Best regards
Russ
You have my vote.
Hello Russ,
At the end of the video you wondered why the lens loss (2" lens) went from 40.1% down to 13.4% loss after only cleaning the mirrors and not touching the lens. You forgot that you fixed the beam alignment through the lens and at 17:27 you calculated you were down to an 8% loss. Still puzzling why you rebounded to a 13.4% loss by the end, but it is less of a mystery than going from 40 to 13 when only touching the mirrors. -Dustin
Hi Dustin
I did spot the bloop as I reviewed the edit but hoped others wouldn't. I figured they may be asleep or at least comatose at that point, so 10 out of 10. I have a new set of copper mirrors on order from China so there's another video in the offing. I tried to think back where this may have gone wrong and I decided that it was when I changed my tube. I was so pleased with the new tube I never checked out the beam performance itself. My original tube had a 6mm diameter beam and I suspect I was lucky in hitting the flat part of the first mirror. With the new beam at 8.5mm diameter, it revealed my incompetence at mirror manufacture.
Best regards
Russ
well now, of course the lens losses would be cumulative from one mirror to the next ... correct? That is to say , wouldn't the loss off of mirror three be the cumulative losses from all three mirrors? If so, maybe better idea to start calculating losses from the lens end of the system then work back towards mirror one ?
Hi
I agree, that would be another way of looking at the loss data. Equally valid would be to use the output from the laser as 100% and use that as the base for calculating the percentage losses along the beam path at each mirror. It doesn't really matter because its is only an indicator of where (and the magnitude of the problem) that has to be solved. If there were no losses at all, the results would be zero at all points regardless of the way that you did the calculations. Thus, it is using this logic that one can argue that all results are relative, and that absolute numbers are not that important. The only thing that remains constant across all calculation methods is the resulting power available after the lens expressed as a percentage of what's coming out the tube. Typical systems would be working well if there were 2% loss at each of the 4 error points. ie 100 watts into mirror 1= 98 watts out . 98 watts into mirror 2 -=96.04 out. 96.04 into mirror 3=94.1 out and 94.1 watts into the lens=92.2 watts at the work surface. As you will see, even though we are taking the cumulative effect into account the DIFFERENCE between this result and the simple 4x2% =8% loss is going to have zero effect on our cutting efficiency. It's arguable that gaining maybe another 3 watts efficiency is not even worth the effort but that just occasionally checking the final output to make sure it does not get out of control is a more efficient method. For those without power meters I have suggested that they run a simple 25mm square test on 3mm acrylic/ply/mdf. Set the power to 65% and find a speed that JUST allows the square to drop out. . Once the critical speed has been established you now have a reference point to check for total system power loss.......but of course no means of tracking it down, other than by trial and error cleaning of the beam path.
Thanks again for your suggestion because it's an interesting and valid point that I will bring into the conversation when I do the next video about losses as I fit my new copper mirrors and lens.
Best regards
Russ
thank you ... glad the moly mirrors fixed the issues. :)
seems to me that the copper mirrors are not flat.
If I remember correctly you made these by hand ...
When you showed the surface of the mirrors for discoloration etc.
I noticed a curvature of the reflections.
Doing test burns should reveal round holes ..
You are correct and that was the problem The curvature had no effect when I was firinga 5.5mm diameter beam at the flat section in the middle of the mirror but when I used my new tube without checking the beam size, the 8.5mm beam impinged on the curved section and ...oops!! If you get to part 2 you will see the outcome.
Best regards
Russ
yeah duh ...
Sorry about that ...
I should have watched the second video before commenting.
Your conclusion was nicely explained there.
No Need to apologise, quite the contrary. Without turning to the last page to see who the murderer was you
deduced the culprit for yourself.
super truck lol superb think you russ
Where can I order lenses?
Hi Ray
These represent the best value for money and the last time I did lens tests, these were best for cutting.
www.cloudraylaser.com/products/china-pvd-znse-focusing-lens-for-co2-laser?variant=43422450824
Make sure you measure your lens and order the correct diameter. 50.8 is the most useful and depending on the way your lens mounts, you may not be able to fit a 38.1 focal length.
These are going to take between 2 and 3 weeks to reach you. For this reason I would order 2 so that you have one in reserve. Of all the things that can go wrong with your machine, damaging a lens is near the top.
Bet wishes
Russ
Russ I am not sure I agree with you on the life of the tube as I have several eBay K40 lasers and one is well over a year old and doing just fine. So if you calculate 365x24 hours is 8760 hours putting it well past 2000 hours meaning it should be dead 4 times over but its not, Again this is not one, but I have two so I don't see this as a fluke. Now I don't use them a lot, but if the shelf life concept is correct, then again I am well past 2000 hours on both and they both work just fine. I do like the idea of testing the beam even weekly as 1 week would be about 1/12 of the 2000 hours so if the loss is linear than the beam should degrade at about 1/12 per week and we should see it. I could buy the 10,000 hours or even 20000 as your correct there will be some level of diffusion from the tube but not that quickly...
There was always a myth about shelf life but I now have contacts within the industry that work directly with China and this is "inside" information and not supposition on my part. As I mentioned in the video my 4000 hour tube is still performing well at almost 7000 hours so I am waiting and watching with an open mind as well. Information such as yours is great to try and build up a real picture.
Many thanks
Russ
Understand and many thanks writing back as I too work a lot (physically) in china but not on laser tubes and tend to be skeptical of most "inside" info I am provided as many times there is a context breakdown. However will definitely start tracking my laser output for grins and giggle as it sounds like a fun experiment too :-) Cheers!
Russ, I kinda agree with DY3DTech.com
I've had my cheap machine for almost a year, and no doubt the tube is well over a year old, and I'm seeing no loss in cutting ability either.
I don't doubt the tubes have a shelf life, but I wonder exactly what the definition of the shelf life is and also what the power characteristic is verses time.
It would make sense for a manufacturer to specify that the tube would operate it its advertised power for a shelf life of N hours.
But at 2 x N it could be that the power is just 10% lower than at N, and most of us would not notice, as we get far more variation in material if we are cutting wood (like i do most of the time) and also a lot of variation in machine setup, (e.g. mirror alignment, dirt on lenses and the mirror etc etc)
Hi Roger
Some of the warranty periods look a bit flaky when you compare with the claimed tube life. But if you look at the Reci spec it's full of all sorts of strange statements
You get a 10 month warranty against a 14month tube life promise BUT if you read the following Reci Spec
2. 2.Operation conditions
Water cooling: using purified water; 3 to 5 liter/minute; water temperature: 10℃-40℃.
The operating environment: temperature 2-40℃; humidity 10-60%.The working current: test current is 32mA. Maximum working current is 32mA. The running
current must be kept below 30mA. The life span can reach 10,000 hours if the current is kept
below 28mA. The ammeter must be connected to the negative electrode of laser tube.
When it is working under over-high current for long term, the negative pole will appear purple and the life span will be
shortened rapidly.
To protect dust from going into the insulation sheath, please wrap it with plastic film.
Although the working/test current is 32mA they say max running current is 30mA but that the 10,000 life span CAN (MAY?) reach 10,000 hours IF you back off even more to 28mA. Without actual facts and figures I cynically interpret this as " you will get 100 watt at 30mA and if you are lucky may get 10,000 working hours from the tube if you never exceed 28ma (which may deliver only 90 watts?)"
The other puzzling thing is that this spec is written for ALL the W6 tubes. but with a range of powers available in the W6 range there cannot be one current figure that suits all.
My point here is that the only fact we can rely on is our own evidence. I am remaining open minded because my tube is already at 1.5 times it's 4000 hour life and like yours, showing no signs of power loss.
My information about tube/shelf life came from contacts within the Chinese laser industry and made some sort of sense when you look very skeptically at the vagueness of tube specifications. All it tells me is that smoke and mirrors is the name of the game here
The only valid tube life evidence is from people that have bought proper tubes from credible manufacturers. Any facts on tube life from ebay machines must be ignored. They all seem to be supplied with tubes from KH Labs (some fake or fictitious organization) that seem to be rounding up production rejects from the big boys and re-badging them to give them a new identity. There must be some collusion within the industry because these tube ONLY appear on Ebay machines. When I was in Ireland recently, I visited Wojciech and he has a nice fat 100watt EFR tube that has been rebadged KH Laser. Shine a light on the back side of the label and you can clearly see its EFR original label. As it happens, it seem to perform quite well.
I hope others with power meters and quality tubes will start doing monthly checks to see if the top power (out of the tube) is dipping off . I am watching mine with interest
Best regards
Russ
Fully agree Russ regarding charting the tube out and have ordered a meter and plan to start posting videos as things as I gain few measurements. :-)
Nice hat :)))
Russ why don't you just use a block of something to put the plastic tool/tab on?
Also OMG where are your gloves when handling that lense.. ahhh poison!! ;)
my guess before watching the second part is the mirrors aren't flat..
Hi Dave
If you make one of those tools and use it you will be able to answer the question for yourself. The whole point of it is to be a quick check.
I had previously (off screen) tried to clean the lens with isopropyl alcohol and also aceteone. and had handled the lens with my cotton glove on. The good news is that I did not die when I touched to lens for a few milliseconds. BUT you are correct, I should practice what I preach!!!
Best regards
Russ
SarbarMultimedia yes maybe and also everyone should watch all your videos that way they would know this and point out your deliberate error to test your students that we have watched all the videos and we're taking all the info in.. hehe
I bet your videos have a really high % watched figure.. :)
I'm 18 minutes into part 2 ATM, I never managed to get my copper mirrors to a point of being happy with their optical performance..
I'm wondering now if it would be better to flat polish a sheet of copper with a know hard/flat surface and then cut out the mirror from that perfectly flat copper sheet.. what are your thoughts?
Also interesting stuff about the hours of life on the tubes.. it seems obvious after you said it but I never thought about it until you said :D
Hi Dave
Deliberate error? You are too kind. I think I was lucky with my copper mirror trials because I was using my old 40watt tbe which had a beam diameter of 6mm. This new tube has a beam 8.5mm diameter and impinges on the soft non-flat extremities of mirror 1. Now the beam is "spraying at the edges and stands no hope at mirrors 2 and 3. I did use flat 1.5mm copper sheet for my mirrors but the polishing on cloth as opposed to using a proper lapping block (which I don't possess) was my real downfall. Someone did suggest I use copper coated circuit board. A very cheap and sensible solution which I have not tested but sounds promising.
To be honest I never look at the viewing statistics. They are what they are. I'm still just an old guy in his man cave having the most fun ever. My other hobby is video and I recognized that my learning journey would make good video material for me to play with my editing suite. I had no expectations other than that there may be a few nerd hobbyists that might see this as "laser porn". I never stop being amazed at the emails I get from all parts of the globe.
Best regards Russ
SarbarMultimedia only issue with PCB board is how flat the substrate is that the coppers bonded two but suppose I can soon test that just need to throw some developer on a bit of undeveloped board and see whats its like.. got a few boards floating around somewhere..
Think might have a look at that tomorrow... I bet you could cut the board with the laser and then just use a sharp knife to cut the copper.. interesting..
Hi Dave
PCB is a product that is usually a no no. However cut from the back face for just a few quick circles it may be OK with lots of extraction and the lid closed. Let me know how you get on
Many thanks for interest
Russ
Shouldn't you be wearing laser safety glasses? Are you at risk of radiation exposure? Thanks!
Hi
Thanks for your concern. Can I get you to view czcams.com/video/kJe16YQlIM0/video.html and make up your own mind.
Best regards
Russ
Noticed the same and while he was wearing glasses (no clue if they are acrylic or glass). However I did also watch the video and it freaked me out when he said "there is nothing dangerous" because of the metal plate! While from a "thermal" perspective Russ is correct as beam will be scattered, however it is still "coherent" light and this creates the risk. As Laser light in the ultraviolet (290 - 400 nm) or far infrared (1400 - 10,600 nm) spectrum can cause damage to the cornea and/or to the lens...
Very good video!!
Can I communicate with you? on Skype, Mail, Viber, Whatsapp
I want to know "where have you bought this device?" and "how many kits i have to buy?"
PLEEEEEASE Give me answer
FINGER UP