EXCELLENT VIDEO! When I first got my machine it was a hell out of alignment; so, having the red pointer was a very good start to get it right and a really good way to understand how mirror alignment works. But I noticed the exact thing. Moving the head around made the red pointer also move. That left me scratching my head, so after I set the mirrors, I double checked with the scorching method, just to be sure. And to be honest, within reason, it was very good. Just minor adjustment was needed. Even the red pointer method does not make a perfect way to align the machine, at least it serves for a coarse tuning. You can give the final touch with the scorching method.
Again like every other video - simplified for a novices like myself and people who have a lot more experience, Thanks russ for your feed back as well when I needed it "regarding my purchase of my so-called K40 and it's 40watt" tube. Just a note for anyone buying a K40 "check the earth wire's at the back because mine was a deathtrap " they had large plastic washers on the small nut+bolt between the powder coated body so had I not removed these washes and removed some powder coating then I could have been brown bread (dead). Hope it help's although no doubt the experienced know all about this issue.
Hi Russ, great work you are doing. I love watching your videos. I do agree with your first statement in this one. There is no need for a red dot pointer adding mass to the head. I use Lightburn Software and I installed a camera which I then calibrated. It is so deadly accurate I have no need for a red dot. The camera has made using the laser so much faster and accurate it is amazing.
Russ, you should do a test with that SPT tube where the red laser dot is inside the tube so it is supposed to be accurate. I know I would love to see if they got it right.
Russ, I enjoy watching your videos from time to time. Just a comment for this one. Parallel rays going through the lens converge at the focal point of the lens. If you make the red dot beam parallel to the laser beam, after going through the lens they will converge in the focal plane and the red dot can align with the laser across the entire range of head motion provided the focus is set correctly on the cutting surface. The only caveat here is that it assumes that the focal length of the lens is the same for red light as it is for 10.4 micron light. This may or may not be true as the refractive index of the lens material may vary across that range of wavelengths. But this can possibly be checked for a given lens material.
Hi Rajiv I see you are a believer in lens theory. For astronomical and camera work and the plotting the path of parallel light rays it works just fine and all my life I had no reason to question it However, the big assumption underlying the theory is about uniform light intensity.. You are quite right that red laser pointer light is at a much lower wavelength (650nm) about 1/16th of the CO2 laser wavelength (10,600nm) and the refractive index of zinc selenide is different for each so focussing will be affected., That is not the real problem with lenses and laser light though. If you look at a diagram of the the light path of any monochromatic light passing through a plano convex lens you will see a phenomenon called spherical aberration ....... take a look at the excellent diagram at the bottom of page 20 users.ntua.gr/eglytsis/OptEng/Aberrations_p.pdfusers.ntua.gr/eglytsis/OptEng/Aberrations_p.pdf As the ray path approaches the axis of the lens, there is VERY little bending. In fact, at the axis, the light passes through with NO focussing action As you move further away from the axis the light paths all focus at different positions . Its an effect I affectionately call "fuzzy focus" Flip the lens and the paths change but there is sill fuzzy focus but over a different range. The real problems with focussing a laser beam are twofold. Its diameter and its intensity distribution.The beam may be parallel but its light intensity is normally (Gaussian) distributed. That means about 70% of the light intensity (it's ability to do damage) is within the central 1/3 of the beam. This means it is passing close to the lens axis and it's focal distance will appear to be much greater that the theoretical. Now take the red dot pointer. That is a laser beam also and has the same Gaussian intensity distribution but is a MUCH smaller beam Smaller beam means even closer to the lens axis and even less focussing action and an even longer apparent focal point . Despite the light/lens properties , in theory the red dot pointer should work fine. However, just begin to imagine now what happens when either or both beam fail to pass PERFECTLY through or parallel to the lens axis. THAT is the REAL problem because the beams exiting the lens will not be coincident. I witnessed another strange phenomenon a week ago when I was at Lotus Laser training some of their guys in the arts of photo engraving, Their machine was set up with a beam combiner to achieve a through-the-lens red dot. I did demonstrate to them the unreliability of the system with pulse dots at the 4 corners of the table that mismatched the red dot by up to 1mm. The red dot is relatively large in comparison to the pulse dot PLUS the fact it is so intense it tends to burn a larger spot on your eyeball. It is only when you occlude the red beam that you can see the error. That aside (my little rant) when I fitted the compound lens for the photo engraving demonstration, and set the correct focal distance. ........there was no red dot. Instead there was a red circular blur about 6mm diameter at 11mm below the nozzle where the laser energy focusses to produce a 0.1mm burn. Hmmmm. that's an interesting puzzle and yet another reason to use the laser beam itself (with a little pulse blip) to tell you where it will hit the material with absolute certainty. One other small point. If you choose to use a gallium arsenide lens the visible light will not pass through!!! Best wishes Russ
SarbarMultimedia Russ, unfortunately the link does not open on my iPad but I am an expert in optics and understand aberration theory very well (you can google me). Laser cutting is a hobby for me that I enjoy very much. I can contribute a little here. Is there a way to continue in a more private framework?
@@rajivlaroia1441 Hi Rajv I greatly appreciate your offer to discuss this subject privately as there is so much I have discovered/observed that cannot be explained by the lens theories that I was taught. It is a fascinating subject that experts seem unwilling to discuss . The lens companies I have contacted claim they make perfect lenses and close down the discussion when I ask why cheap Chinese lenses with much greater aberration cut 3 times faster It's almost an attitude that once they have focussed the light ( with great precision), what happens after that is not their problem. If you care to add your disguised email address (johndotsmithatgooglemaildotcom) to another comment I would be overjoyed to begin an offline discussion. Mamy many thanks Russ
Considering the laser is nothing more than a concentrated beam of light 12mm in diameter, if you were to have a 12mm beam of intense visible light would the lens focus that beam to show what the actual dot size would be(of course provided there were no alignment errors)? Back to your pointer though, have you considered using a stalk coming down from the carriage to mount the pointer on. Since it's main goal is to align the head to the work, movement of the stalk during a cutting session would be irrelevant.
Hi The Chinese always hang a single red pointer off the head hear the nozzle.. To be honest it is pretty useless because any slight change of focus caused the dot to synchronize with the beam impact point. Thus ANY single point source , however and wherever it is mounted, will suffer the same functional impairment. The only method I have encountered that overcomes this problem is two line generating leds mounted 90 degrees to each other. This produces a static cross hair that is focus insensitive. But the whole point of this lightweight head is in the title. I could have gone overboard and removed even more weight by truncating the lens tube and dispensing with air assist as do Trotec and Epilog. That results in loss of functionality and seriously compromises the laser's potential . My goal has always been to create a very low cost high performance machine that is an embarrassment to those hideously priced pieces of grand engineering. I feel I am making serious headway and adding mass in any form is counter to my aims. I have survived for 5 years with two machine and no red dot pointer. If you REALLY need to know PRECISELY where your beam will land, you always have a pulse button . Thanks for your comment because it does allow me to indicate that my goals are different to many others with these machines. I never loose sight of that fact and that any improvements YOU wish to make to YOUR machine will give you satisfaction and a sense of having overcome an issue that is a problem for you. Best wishes Russ
@@SarbarMultimedia Oh I understand the goal completely. When you mentioned mass, I was thinking that a separate stalk not attached to the tube might work so it wouldn't upset the laser focus. Only thing I use the pointer for is to verify framing, otherwise it is so out of position that it is a guessing game. If the part moves, toss it since it will never go back to the same spot. I do like the idea of crosshairs though. The only time the laser spot is nearly accurate is when the distance is correct, but no matter what I try, it is always a bit off to one side or the other, so I don't bother anymore. Another thought I had, but not sure if it would work is a series of fixed mirrors attached to the gantry that would not change distance, but I don't think the beam could be aligned to point straight down when it hits the head mirror. Lets see if I can get the image across, the pointer would be atop the final mirror pointing towards the left, a mirror in front of it pointing the beam down, a 12MM gap for the laser beam between mirrors, and the bottom mirror pointing the beam to the tube mirror, but I don't think it can be adjusted properly to get the beam dead center down the tube. Keep up the good work, been watching your vids since mine arrived and learned a lot. I now have upgraded to copper mirrors, and a good 2" lens and it is cutting much better, though I still can't get as fine a cut as commercial lasers do, but still good enough to make the parts I need. These Chinese Lasers (Chasers) aren't bad really, a few minor upgrades and they do a remarkable job.
I wonder if it's possible to make a swing-in adjustable bracket which holds a laser module, and a thin plate-type beam splitter, with the hope being that you could bounce the visible laser from the laser-tube's mirror, that you might have an indication of alignment, before sending the beam down the rest of the system. The assembly would have to swing out of the way, so that the co2 laser does not incinerate the LED laser module/pointer. A plain piece of glass might indicate if it's practical, before any other investment of time/effort, but it would only reflect a few percent, per surface. [When I was a kid, I wanted to make a fanciful and naive dye laser (like most normal kids) with just dye cell and a ring of LEDs. I made kinetic mounts for the mirrors using only blob of silicone sealer and screws. I told you it was fanciful. Anyway, I sighted through the system to line up the mirrors, with the system being off, or course.]
I thought I had it nailed when I made the one piece tube and mirror mount. I was sure that the manufacturing accuracy of the tube would be good enough for me to know exactly where the beam axis would exit and that I could set a diode onto the beam axis and then steer it so that it aligned with the beam axis. Again about 95% ok but not perfect. That was basically Mk8 and in this video I show why any small errors will prevent the perfection you can achieve with the scorch method.. Until I can afford an integrated red pointer tube from SPT, my red pointer days are finished.. Your thoughts are interesting and I'm glad to have stimulated your interest. Best wishes Russ.
I just finished installing a Cloudray beam combiner on my red and black machine. The version I received from Cloudray didn't have the aluminum blocking piece. The reflected beam is strong enough to burn MDF. I took a rather disturbing video of the results.
Hi I have just looked at the combined mirror 1 and beam combiner. I can see so obviously that this IS a dangerous product. I will immediately speak to the head man at Cl;oudray and ask for its withdrawal and if you write separately to Cloudray and politely complain and ask for a refund. By all means link your video to them. I do not need to see it I have personally witnessed these items in the flesh pre installed on machines from China.. Thanks for letting me know. Any form of beam combiner costs you 5 to 8% power loss (that's your reflected energy) and will NEVER perfectly match the invisible laser beam. You will get more benefit by spending the money on a surprise gift for your wife.. Best wishes Russ
Hi I have advised Cloudray of the product's dangers and they have withdrawn it from sale pending the addition of a heat sink/shield. They were planning to contact all purchasers to offer a refund. Thanks for letting me know. Best wishes Russ
hi Russ. like the video. I was wondering if you would like to give the SPT tube a try. I have recently aquired one and lend it for a test. if you want to give ir a try please get in touch.
Hi Martin Your offer is very generous and I genuinely appreciate the thought. You may remember that a few months ago I swapped out an EFR 60 watt tube that was showing "blunt" photo engraving characteristics and replaced it with a 70 watt SPT tube from Cloudray. I make no secret of the non-commercial "gentleman's relationship" that i have with Cloudray. He makes and sells my ideas/designs to the laser community at Chinese prices and in return I get whatever support equipment I require for my experiments. At that point in time he would have sent me the red beam tube but I decided that for me it was an unnecessary . I had spent much time experimenting with many iterations of red dot beam simulators including beam combining, all with limited success. During all that time I was developing logical methods and machine elements that allowed me quick, simple and perfect beam setting using that horrible scorch method. Do it enough and it becomes easy when you have a logical approach. I thought long and hard about how I would use the red beam "dream tube" for setting mirrors. It seemed to fulfil my dream to find an easy dynamic setting method. I stopped and thought through the method I would have to use and realized you would need a cross hair target on each mirror and you would therefore have to make sure your (fairly large) red dot was centered on the cross hair perfectly. because if its not on centre you would be relying on visual memory for "judging" coincidence.. The scorch method actually wins because it creates its own target mark that can be 2 or 3 mm off centre (vertically for mirrors 1 and 2) and not affect the beam path. No visual memory involved. The red beam on the other hand, forces the almost impossible (and unnecessary) need to have ALL your mirrors perfectly on one plane. Coincidence is vital for each axis,, mirror centrality is not. It was at that stage of choosing an SPT tubek, with or without the red beam, that I went the tried and tested route because I began to realize that the grass on the other side of the fence was not as green as I had always imagined. Once setup by the scorch method, you will have an excellent "through the lens" red dot pointer for locating your head position/origin . However, I ripped the red dot pointers off both my machines within days and have survived 5 years without them. If I need accurate location, a quick blip of the pulse button gets me there. with 100% certainty. Again I really do thank you for the great offer but the logic that finally put my red beam dream to death is still valid. I am still in mourning!!! Best wishes Russ
Russ thanks for taking the time to do all these videos. Have you tried to alignment using a laser pointer that goes into the lens tube and work backwards? I see ads of people selling it as the golden way of alignment
Hi Jaco As recently as a week ago I had the same question from a guy that sent me the link to the device you mentioned. Here was my answer That's very interesting. I tried using a video camera a long time ago in a similar "backward" manner to look right back into the laser window and along the tube to see if I could catch a reflection off the anode mirror. Even with strong light I didn't succeed. That was long before I realized just how important that beam axis is. Maybe it is this kit you mention above which has prompted several recent questions about the subject. Previously I have had 3 or 4 questions about the subject over as many years. As I always tell people there is just one fundamental flaw with the method and that is how do you align the tube axis with a red beam. Sorry, that is really mission impossible. In my previous video I failed to explain clearly how even a forward pointing red beam has proved virtually impossible to align perfectly. I have just issued a follow up that breaks the problem down and explains why all my 8red dot pointers were "nearly" successes. If the backward method falls at the final hurdle then what is the benefit? Much as I hate the scorch method, it can be quick and perfect and does not require the beam to be precision centred on each mirror. I can go from new tube to perfect alignment of 3 axes in less than 15 minutes. I have really lost count of how many times I have done it whereas most people fear doing it once. Thanks for the link and I would be interested if you know of any success with the kit. If you watch this video from about 13m 15sec, ruclips.net/video/fV95IG1GyYc/видео.html I go through quickly the logical impossibility of setting the beam backwards I have now watched the video demonstration for the device you mention ....hmmmm....so much of the procedure is missing and the vital part about aligning the beam with the target that you must put on mirror 1 fails to mention how putting the beam to match mirror 1 red dot does NOT align it with the red beam. Much as I hate the scorch method, the simple procedure I have developed along with making the head adjustable is the ONLY way to achieve setting perfection. It's your money so I can only warn you of the risks Best wishes Russ
Russ it has been a while since I watched a video. Fantastic as always I appreciate you taking time to do these. Could you set up each of those lasers to focus at a different point (each corner, one center, etc.) on the travel so you as one gets diffused by the lense another takes over? I still think you are going to have dead spots so that likely wouldn't work either, just wonder if you had thought of that. You are smarter than me I am sure you have.
Hi Aaron Nice thought but sadly , no for two reasons.1) At back left corner I cannot hit mirror 2 with any of the red beams even if the laser beam was set mirror dead centre, which it is not because precision is not necessary because within 2mm will be OK 2) The whole principle is to get as close to parallel and axially true to the laser beam. With what I am attemptin it is impossible to achieve because the red beam will always be converging onto the laser beam at some defined point. Set any one of those beams off and it will have a different angle and off axis position when it strikes the lens . That in turn cuses the red beam to veer off the track of the main laser beam. The principle of using 4 dots was that if this happened you would have 4 corner dots on your work and hopefully the beam would strike in the centre of the pattern. Adjust them to different convergent positions and that regular pattern of 4 dots will be destroyed. Sadly I never got near to finding out. Best wishes Russ
Looks more like you've added a second laser that has to be recalibrated just as frequently as the main one. Does the second laser improve your workflow enough to justify the added futzing?
That's exactly the point about any secondary visible laser, usually a beam combiner, its a second beam that is almost impossible to perfectly match to the invisible beam Too much trouble and not truthful Best wishes Russ
Thanks Russ for your time and another video. Please keep them coming, most enjoyable
EXCELLENT VIDEO! When I first got my machine it was a hell out of alignment; so, having the red pointer was a very good start to get it right and a really good way to understand how mirror alignment works. But I noticed the exact thing. Moving the head around made the red pointer also move. That left me scratching my head, so after I set the mirrors, I double checked with the scorching method, just to be sure. And to be honest, within reason, it was very good. Just minor adjustment was needed.
Even the red pointer method does not make a perfect way to align the machine, at least it serves for a coarse tuning. You can give the final touch with the scorching method.
Again like every other video - simplified for a novices like myself and people who have a lot more experience,
Thanks russ for your feed back as well when I needed it "regarding my purchase of my so-called K40 and it's 40watt" tube.
Just a note for anyone buying a K40 "check the earth wire's at the back because mine was a deathtrap " they had large plastic washers on the small nut+bolt between the powder coated body so had I not removed these washes and removed some powder coating then I could have been brown bread (dead).
Hope it help's although no doubt the experienced know all about this issue.
Hi Russ, great work you are doing. I love watching your videos. I do agree with your first statement in this one. There is no need for a red dot pointer adding mass to the head. I use Lightburn Software and I installed a camera which I then calibrated. It is so deadly accurate I have no need for a red dot. The camera has made using the laser so much faster and accurate it is amazing.
Another Great Job … Well Done! Thanks for proving all our failures & Why!!
Love your videos, you taught me how to how to calibrate my laser when I was building my laser machine and was having good results almost straight away
You are helping me deal with stress and that I am grateful for
Russ, you should do a test with that SPT tube where the red laser dot is inside the tube so it is supposed to be accurate. I know I would love to see if they got it right.
SPT should send him a free tube. After watching his video it made me run to their website to learn more about it.
@@victoraigner SPT is quality stuff and rebadged as Cloudray. If I ever purchase another Chinese tube it will be SPT.
When it comes time to replace my 5 year old 70 watt Mactron tube it will be with one of these tubes
best wishes
Russ
Russ, I enjoy watching your videos from time to time. Just a comment for this one. Parallel rays going through the lens converge at the focal point of the lens. If you make the red dot beam parallel to the laser beam, after going through the lens they will converge in the focal plane and the red dot can align with the laser across the entire range of head motion provided the focus is set correctly on the cutting surface. The only caveat here is that it assumes that the focal length of the lens is the same for red light as it is for 10.4 micron light. This may or may not be true as the refractive index of the lens material may vary across that range of wavelengths. But this can possibly be checked for a given lens material.
Hi Rajiv
I see you are a believer in lens theory. For astronomical and camera work and the plotting the path of parallel light rays it works just fine and all my life I had no reason to question it However, the big assumption underlying the theory is about uniform light intensity.. You are quite right that red laser pointer light is at a much lower wavelength (650nm) about 1/16th of the CO2 laser wavelength (10,600nm) and the refractive index of zinc selenide is different for each so focussing will be affected., That is not the real problem with lenses and laser light though. If you look at a diagram of the the light path of any monochromatic light passing through a plano convex lens you will see a phenomenon called spherical aberration ....... take a look at the excellent diagram at the bottom of page 20 users.ntua.gr/eglytsis/OptEng/Aberrations_p.pdfusers.ntua.gr/eglytsis/OptEng/Aberrations_p.pdf
As the ray path approaches the axis of the lens, there is VERY little bending. In fact, at the axis, the light passes through with NO focussing action As you move further away from the axis the light paths all focus at different positions . Its an effect I affectionately call "fuzzy focus" Flip the lens and the paths change but there is sill fuzzy focus but over a different range.
The real problems with focussing a laser beam are twofold. Its diameter and its intensity distribution.The beam may be parallel but its light intensity is normally (Gaussian) distributed. That means about 70% of the light intensity (it's ability to do damage) is within the central 1/3 of the beam. This means it is passing close to the lens axis and it's focal distance will appear to be much greater that the theoretical. Now take the red dot pointer. That is a laser beam also and has the same Gaussian intensity distribution but is a MUCH smaller beam Smaller beam means even closer to the lens axis and even less focussing action and an even longer apparent focal point . Despite the light/lens properties , in theory the red dot pointer should work fine. However, just begin to imagine now what happens when either or both beam fail to pass PERFECTLY through or parallel to the lens axis. THAT is the REAL problem because the beams exiting the lens will not be coincident.
I witnessed another strange phenomenon a week ago when I was at Lotus Laser training some of their guys in the arts of photo engraving, Their machine was set up with a beam combiner to achieve a through-the-lens red dot. I did demonstrate to them the unreliability of the system with pulse dots at the 4 corners of the table that mismatched the red dot by up to 1mm. The red dot is relatively large in comparison to the pulse dot PLUS the fact it is so intense it tends to burn a larger spot on your eyeball. It is only when you occlude the red beam that you can see the error. That aside (my little rant) when I fitted the compound lens for the photo engraving demonstration, and set the correct focal distance. ........there was no red dot. Instead there was a red circular blur about 6mm diameter at 11mm below the nozzle where the laser energy focusses to produce a 0.1mm burn. Hmmmm. that's an interesting puzzle and yet another reason to use the laser beam itself (with a little pulse blip) to tell you where it will hit the material with absolute certainty.
One other small point. If you choose to use a gallium arsenide lens the visible light will not pass through!!!
Best wishes
Russ
SarbarMultimedia Russ, unfortunately the link does not open on my iPad but I am an expert in optics and understand aberration theory very well (you can google me). Laser cutting is a hobby for me that I enjoy very much. I can contribute a little here. Is there a way to continue in a more private framework?
@@rajivlaroia1441
Hi Rajv
I greatly appreciate your offer to discuss this subject privately as there is so much I have discovered/observed that cannot be explained by the lens theories that I was taught. It is a fascinating subject that experts seem unwilling to discuss . The lens companies I have contacted claim they make perfect lenses and close down the discussion when I ask why cheap Chinese lenses with much greater aberration cut 3 times faster It's almost an attitude that once they have focussed the light ( with great precision), what happens after that is not their problem. If you care to add your disguised email address (johndotsmithatgooglemaildotcom) to another comment I would be overjoyed to begin an offline discussion.
Mamy many thanks
Russ
Considering the laser is nothing more than a concentrated beam of light 12mm in diameter, if you were to have a 12mm beam of intense visible light would the lens focus that beam to show what the actual dot size would be(of course provided there were no alignment errors)? Back to your pointer though, have you considered using a stalk coming down from the carriage to mount the pointer on. Since it's main goal is to align the head to the work, movement of the stalk during a cutting session would be irrelevant.
Hi
The Chinese always hang a single red pointer off the head hear the nozzle.. To be honest it is pretty useless because any slight change of focus caused the dot to synchronize with the beam impact point. Thus ANY single point source , however and wherever it is mounted, will suffer the same functional impairment. The only method I have encountered that overcomes this problem is two line generating leds mounted 90 degrees to each other. This produces a static cross hair that is focus insensitive. But the whole point of this lightweight head is in the title. I could have gone overboard and removed even more weight by truncating the lens tube and dispensing with air assist as do Trotec and Epilog. That results in loss of functionality and seriously compromises the laser's potential . My goal has always been to create a very low cost high performance machine that is an embarrassment to those hideously priced pieces of grand engineering. I feel I am making serious headway and adding mass in any form is counter to my aims. I have survived for 5 years with two machine and no red dot pointer. If you REALLY need to know PRECISELY where your beam will land, you always have a pulse button .
Thanks for your comment because it does allow me to indicate that my goals are different to many others with these machines. I never loose sight of that fact and that any improvements YOU wish to make to YOUR machine will give you satisfaction and a sense of having overcome an issue that is a problem for you.
Best wishes
Russ
@@SarbarMultimedia Oh I understand the goal completely. When you mentioned mass, I was thinking that a separate stalk not attached to the tube might work so it wouldn't upset the laser focus. Only thing I use the pointer for is to verify framing, otherwise it is so out of position that it is a guessing game. If the part moves, toss it since it will never go back to the same spot. I do like the idea of crosshairs though. The only time the laser spot is nearly accurate is when the distance is correct, but no matter what I try, it is always a bit off to one side or the other, so I don't bother anymore.
Another thought I had, but not sure if it would work is a series of fixed mirrors attached to the gantry that would not change distance, but I don't think the beam could be aligned to point straight down when it hits the head mirror. Lets see if I can get the image across, the pointer would be atop the final mirror pointing towards the left, a mirror in front of it pointing the beam down, a 12MM gap for the laser beam between mirrors, and the bottom mirror pointing the beam to the tube mirror, but I don't think it can be adjusted properly to get the beam dead center down the tube.
Keep up the good work, been watching your vids since mine arrived and learned a lot. I now have upgraded to copper mirrors, and a good 2" lens and it is cutting much better, though I still can't get as fine a cut as commercial lasers do, but still good enough to make the parts I need. These Chinese Lasers (Chasers) aren't bad really, a few minor upgrades and they do a remarkable job.
I wonder if it's possible to make a swing-in adjustable bracket which holds a laser module, and a thin plate-type beam splitter, with the hope being that you could bounce the visible laser from the laser-tube's mirror, that you might have an indication of alignment, before sending the beam down the rest of the system.
The assembly would have to swing out of the way, so that the co2 laser does not incinerate the LED laser module/pointer.
A plain piece of glass might indicate if it's practical, before any other investment of time/effort, but it would only reflect a few percent, per surface.
[When I was a kid, I wanted to make a fanciful and naive dye laser (like most normal kids) with just dye cell and a ring of LEDs. I made kinetic mounts for the mirrors using only blob of silicone sealer and screws. I told you it was fanciful. Anyway, I sighted through the system to line up the mirrors, with the system being off, or course.]
I thought I had it nailed when I made the one piece tube and mirror mount. I was sure that the manufacturing accuracy of the tube would be good enough for me to know exactly where the beam axis would exit and that I could set a diode onto the beam axis and then steer it so that it aligned with the beam axis. Again about 95% ok but not perfect. That was basically Mk8 and in this video I show why any small errors will prevent the perfection you can achieve with the scorch method.. Until I can afford an integrated red pointer tube from SPT, my red pointer days are finished.. Your thoughts are interesting and I'm glad to have stimulated your interest.
Best wishes
Russ.
I just finished installing a Cloudray beam combiner on my red and black machine. The version I received from Cloudray didn't have the aluminum blocking piece. The reflected beam is strong enough to burn MDF. I took a rather disturbing video of the results.
Hi
I have just looked at the combined mirror 1 and beam combiner. I can see so obviously that this IS a dangerous product. I will immediately speak to the head man at Cl;oudray and ask for its withdrawal and if you write separately to Cloudray and politely complain and ask for a refund. By all means link your video to them. I do not need to see it I have personally witnessed these items in the flesh pre installed on machines from China.. Thanks for letting me know. Any form of beam combiner costs you 5 to 8% power loss (that's your reflected energy) and will NEVER perfectly match the invisible laser beam. You will get more benefit by spending the money on a surprise gift for your wife..
Best wishes
Russ
Hi
I have advised Cloudray of the product's dangers and they have withdrawn it from sale pending the addition of a heat sink/shield. They were planning to contact all purchasers to offer a refund.
Thanks for letting me know.
Best wishes
Russ
Thanks for the upload
hi Russ. like the video. I was wondering if you would like to give the SPT tube a try. I have recently aquired one and lend it for a test. if you want to give ir a try please get in touch.
Hi Martin
Your offer is very generous and I genuinely appreciate the thought. You may remember that a few months ago I swapped out an EFR 60 watt tube that was showing "blunt" photo engraving characteristics and replaced it with a 70 watt SPT tube from Cloudray. I make no secret of the non-commercial "gentleman's relationship" that i have with Cloudray. He makes and sells my ideas/designs to the laser community at Chinese prices and in return I get whatever support equipment I require for my experiments. At that point in time he would have sent me the red beam tube but I decided that for me it was an unnecessary . I had spent much time experimenting with many iterations of red dot beam simulators including beam combining, all with limited success. During all that time I was developing logical methods and machine elements that allowed me quick, simple and perfect beam setting using that horrible scorch method. Do it enough and it becomes easy when you have a logical approach. I thought long and hard about how I would use the red beam "dream tube" for setting mirrors. It seemed to fulfil my dream to find an easy dynamic setting method. I stopped and thought through the method I would have to use and realized you would need a cross hair target on each mirror and you would therefore have to make sure your (fairly large) red dot was centered on the cross hair perfectly. because if its not on centre you would be relying on visual memory for "judging" coincidence.. The scorch method actually wins because it creates its own target mark that can be 2 or 3 mm off centre (vertically for mirrors 1 and 2) and not affect the beam path. No visual memory involved. The red beam on the other hand, forces the almost impossible (and unnecessary) need to have ALL your mirrors perfectly on one plane. Coincidence is vital for each axis,, mirror centrality is not. It was at that stage of choosing an SPT tubek, with or without the red beam, that I went the tried and tested route because I began to realize that the grass on the other side of the fence was not as green as I had always imagined.
Once setup by the scorch method, you will have an excellent "through the lens" red dot pointer for locating your head position/origin .
However, I ripped the red dot pointers off both my machines within days and have survived 5 years without them. If I need accurate location, a quick blip of the pulse button gets me there. with 100% certainty.
Again I really do thank you for the great offer but the logic that finally put my red beam dream to death is still valid. I am still in mourning!!!
Best wishes
Russ
Russ thanks for taking the time to do all these videos. Have you tried to alignment using a laser pointer that goes into the lens tube and work backwards? I see ads of people selling it as the golden way of alignment
Hi Jaco
As recently as a week ago I had the same question from a guy that sent me the link to the device you mentioned.
Here was my answer
That's very interesting. I tried using a video camera a long time ago in a similar "backward" manner to look right back into the laser window and along the tube to see if I could catch a reflection off the anode mirror. Even with strong light I didn't succeed. That was long before I realized just how important that beam axis is. Maybe it is this kit you mention above which has prompted several recent questions about the subject. Previously I have had 3 or 4 questions about the subject over as many years. As I always tell people there is just one fundamental flaw with the method and that is how do you align the tube axis with a red beam. Sorry, that is really mission impossible. In my previous video I failed to explain clearly how even a forward pointing red beam has proved virtually impossible to align perfectly. I have just issued a follow up that breaks the problem down and explains why all my 8red dot pointers were "nearly" successes. If the backward method falls at the final hurdle then what is the benefit? Much as I hate the scorch method, it can be quick and perfect and does not require the beam to be precision centred on each mirror. I can go from new tube to perfect alignment of 3 axes in less than 15 minutes. I have really lost count of how many times I have done it whereas most people fear doing it once. Thanks for the link and I would be interested if you know of any success with the kit.
If you watch this video from about 13m 15sec,
ruclips.net/video/fV95IG1GyYc/видео.html
I go through quickly the logical impossibility of setting the beam backwards
I have now watched the video demonstration for the device you mention ....hmmmm....so much of the procedure is missing and the vital part about aligning the beam with the target that you must put on mirror 1 fails to mention how putting the beam to match mirror 1 red dot does NOT align it with the red beam.
Much as I hate the scorch method, the simple procedure I have developed along with making the head adjustable is the ONLY way to achieve setting perfection. It's your money so I can only warn you of the risks
Best wishes
Russ
Russ it has been a while since I watched a video. Fantastic as always I appreciate you taking time to do these.
Could you set up each of those lasers to focus at a different point (each corner, one center, etc.) on the travel so you as one gets diffused by the lense another takes over? I still think you are going to have dead spots so that likely wouldn't work either, just wonder if you had thought of that. You are smarter than me I am sure you have.
Hi Aaron
Nice thought but sadly , no for two reasons.1) At back left corner I cannot hit mirror 2 with any of the red beams even if the laser beam was set mirror dead centre, which it is not because precision is not necessary because within 2mm will be OK 2) The whole principle is to get as close to parallel and axially true to the laser beam. With what I am attemptin it is impossible to achieve because the red beam will always be converging onto the laser beam at some defined point. Set any one of those beams off and it will have a different angle and off axis position when it strikes the lens . That in turn cuses the red beam to veer off the track of the main laser beam. The principle of using 4 dots was that if this happened you would have 4 corner dots on your work and hopefully the beam would strike in the centre of the pattern. Adjust them to different convergent positions and that regular pattern of 4 dots will be destroyed. Sadly I never got near to finding out.
Best wishes
Russ
Looks more like you've added a second laser that has to be recalibrated just as frequently as the main one. Does the second laser improve your workflow enough to justify the added futzing?
That's exactly the point about any secondary visible laser, usually a beam combiner, its a second beam that is almost impossible to perfectly match to the invisible beam Too much trouble and not truthful
Best wishes
Russ
Hello, I think you need a smoke evacuator, I am a smoke evacuator manufacturer in China
I have a PUREX smoke evacuator but I did not turn it on
Thanks