Bernd, I fully agree.
I love the things I can do with the lasr and its a learning experience for me right now. I get to know the machine much more than before, as you always learn most from the failures. I will get this machine working as it should, there’s no doubt.
And you guys are really helpful because you care for my problems, otherwise I would be lost.
When I saw Lightburn software I didn’t even think about looking on RDWorks, because it was overwhelming with smart functionality. Now I find, that the forum is equally beyond my expactations. So thanks for this to all of you.
I have also contacted the supplier of the machine and got a response today, that they are on holidays until tomorrow (5 days labor day in china, they stop all working and get home to the places they come from to celabrate with their families), but she has forwarded to their engineers and probably I get some answers by end of this week. She wrote this on her holiday (!).
Normally, I would like to buy you a beer or two, but (not only due to corona) we need to find some remote alternative. In the meantime, this is all I can do:
I think I have now seen 5 or 6 of his videos, very interesting. Thank you for the link.
Yes, seems as I have a B-Grade Laser Tube. But I actually bought a 100W laser, not a 130W. I understand from the video, that you should only use a certain percentage of the laser peak watt (or mA) and that means 28 instead of 30 mA, which is 93%. 117 * 93% is still 108W. The second thing was using max. up to 26mA to reach the 10.000 hours lifetime. If I do that, I still have 117 * 86,6% = 101W. Remember I bought a 100W laser, so I’m fine in this regards. And anyway I try to not go beyond 80% of the laser power.
What I’m not fine with is, obvioulsy I trashed something but I don’t know what. I have not touched the laser, I have treated the lens gently. I just aligned the mirrors again to make sure I have a proper laserpath, cleaned everything including the lens in order to get a better result.
And then this big fat laser beam…
If I have trashed the lens, fine. I buy a new one.
If I have trashed the lasertube, fine. I buy a new one and experience the trouble to replace the tube.
But I have absolutely no clue what is the problem. And this makes me mad as I don’t know how to fix it.
Just thinking out of the box. I do not know how you air assist is attached to your laser but if mounted like this one thing that could happen. If the lens is not firmly held in place the pulsing of the air coming from the compressor could be lifting and vibrating the lens. You said you changed the compressor too.
Even tried without air assist, same result. Kompressor rechanged again, as the new one was not appropriate for continuous operation. Will find another one when the current problem is solved.
I think you will find that the plywood is warped. Slightly out of focus in that area will cause the problem you have. I cut a lot of 1/4" birch paneling and warping is the #1 cause of leaving strands uncut. Sometimes you can re focus in the bad area and overcut it again at reduced power or at increased speed. This can save a lot of time, frustration and material.
Yes agree, the plywood is always warped. However, the bad cut was in all areas, even in the flat ones. And I always put the plywood with the warped side going up, this focuses more in the material which normally give a better cut.
I will consider the second cut as you suggested, as soon as I have solved the other (even bigger) problem.
Electiric Power maybe a possibility ?
When I see the wide beam not much burning and whatever I do I get the same result, this lets me always think about the lens being the problem. But I don’t think it is, because it sits correct in the lens tube and I also tried the spare lens that came with the machine.
I have made two observations about the electric part of the machine.
Since the beginning it makes a “Klong” noise when I power off the machine. Maybe the power adapter has a problem… (?)
I opened the Driver opening and saw that the GND LED is blinking. I never noticed that, but at the same time I never really looked at it. The Ground Cable of the machine is connected to the Ground Cable of my power network for the house. Blinking LEDs are never a good sign and maybe there’s a problem inside the machine with the Grounding. Haven’t looked at it yet, but maybe a possibility ?
The question is now, could one of these potential problems lead to the result I see when burning ? Or can we exclude this from the failure analysis ?
It could well be that sound comes when the controller releases “hold” of the steppes. I can also sense this klong sound but with me it is when power comes to the motors to “hold” them.
Not necessarily, with normal on / off switches yes but with data transmission indication LEDs it is normal with some controllers. Slow blinking - I’m ready, fast blinking - I’m doing something.
the vendor wants to help, but I think they have no idea what is going on (me neither). So they say that the laserpath is not aligned. As this whole mess happened when I wanted to optimize the laser path, I thought I give it a try - and to align with the vendor. The result - same as before:
I found it very hard and at the end impossible to align the second mirror on both, short and long distance to the first mirror. Below you can see below the following target cards:
Upper left Card: Long Position (Front) aligned to the middle, Short Position (Rear) was shooting to the right
Upper Right Card: Short Position (Rear) aligned to the middle, Long Position (Front) was way to the left
Lower left Card: This is the closest I could get the beams together, but not alogned to the middle
Lower right card: After I aligned the middle position (Half way to the front), I did a quick test with Mirror 3 which was quite ok. Just wanted to start a cut to see if something has changed. Unfortunately it hasn’t. Tape under the nozzle was in the middle
I told the vendor, that I don’t think the laser Path has anything to do with the result you see above. Even if the laser path is not fully aligned, the beam would be much thinner. The beams on my laser are huge, even at the first mirror. Also shown him a screenshot from the video which was suggested earlier in this thread. The beam was less than half the size.
I remember, when I first tried the laser when it came. It didn’t cut, but the beam was thin. I aligned the laser path and it cut through some material. The problem was, it never cut everything, something was always left uncut.
The size of your test shots is not too big but that you can not center your beam I do not understand.
With what I see in mirrors no. 3, you should still have a thinner focus point if your lens is ok and you do not have a huge error deviation of your distance from the lens to the workpiece. Did you do the ramp test we were talking about?
Find the mirror alignment instructions on the k40laser.se site and follow it step by step. It explains what has to be done at each mirror and explains the steps based on the results obtained. And if things are so out of whack you have to shim your mirrors or movement frame it’s covered too.
@Hank , yes I cleaned the mirrors all the time because there were some condensate from the pulse. I use an optical lens cleaning fabric, The metal front tube looks normal, there was some dust which I cleaned with the same.
@bernd.dk
As you can see in the upper left card, I centered the beam in the long distance for mirror 2, and when I shot in the rear position it was on the right. So the beam goes like this:
Next step which you can see in the second card (upper right) I aligned the short distance to the center and of course in the long distance the beam was much more on the left.
To change this, I shifted half the way to the right again and this is what you can see in the 3rd card (lower left), where they are very close. I could get them even closer, but it will never be in the center.
How do I align the second shot when the first was in the center ? Of course it will affect the other and you can adjust this. But as the long position way is x times longer than the short position, it will always move faster to the side you’re adjusting to. You can’t have one position centered and then center the other one without affecting the first.
I even moved the 2nd mirror in the x-Axis to see if I can fix this, but more or less the same. Unfortunately I can’t move the x-Axis of the first mirror as this would be more logical to me.
What am I missing here ?
But the more important question: Could this really be the reason for the issue I have with the wide beam whatever I do ? Like there was no lens… ?
