[herby08]

hi dom
thats correct if you shift the 2nd mirror the beam will sure shift thats why you have to do the mechanical checking first and then move on to the beam check and adjusting.
the best to start is take all the setscrews back and then start at mirror one,
move on to mirror two and so on.
for the probleme with the beam to the laser head thats why it is very importend to make sure that the laser head is paralell to the gantry and
the laserhead is horizontal in center line of mirror two, only then you can move on.
everythings else does not help you, it just confuese you
greetings
walt

Thanks Walt

I really stated today going through the machine checking the levels and squareness. But as I had to go out I didn't get this finished. But I did find that the second mirror was not set at 45 degrees and so I shifted this but have not tightened it up yet. I know the last time I tested the beam I noticed that the beam was not in the same place in the second mirror when I shifted that mirror from the back to the front of the machine. And I still have to parallel the laser head to the gantry and second mirror. I have also noticed that when I have shifted the second mirror the beam shifts from going towards the tube to going above the laser head. So that's another issue I have to get around. Any help with these problems?

Thanks Dom

[FanFan]

"I replaced the mirrors because there was no spares with the machine and I accidentally burnt a hole in one. Now for the beam. It was not hitting the middle of the first mirror, so I had to adjust the tube. The beam is pretty good between the first and second mirrors. Between the second mirror and the laser head when the head is closest to the mirror and close to the tube the beam is 10mm left and 10mm high on the head. When it is in far away position the beam is 55mm left and 35mm high. Which is saying the mirror is not set at 45 degrees and I have tested it today with a set square and that is true it is not set right. I have taken the mirror set screws right back to test the beam in it's unadjusted position. This k40 machine build quality is poor and we have to completely reset things to get it working. "

Dom, thanks for you reply. Just so that we are on the same page. Before replacing the mirrors the laser was working okay, right? The test shot were coming out okay? They were centered? So things went a little wacky when the mirrors got replaced, right? Just checking, where did you get the replacement mirrors?

So back to the beam. If we follow the beam out of the laser:
1. It strikes the first mirror and it is pretty much centered.
2. It reflects off the first mirror and strikes the second mirror when the 1 st and 2 nd mirrors are close to each other ( as close as they physically can be.)
At this point on the 2nd mirror the test shot is postioned at 10mm and 10 mm, correct? You mean that the shot is centered, right? I am just making this point to make sure that I understand your point of view. ( I would call that spot 0, 0. but that is just a personal preference).
3. In my last post I mentioned moving 2nd mirror half the allowable distance away from mirror # 1. I am sure that the test shot dot must have moved off dead center, right. Do you know how much? and in what direction?
3. Okay , now you move the 2nd mirror as far as away from the the 1 st mirror and took a test shot. That one is off postion by 55 mm left and 35 mm high. Just so I know are those numbers referenced to 0,0 or 10,10 ? Either way there is an error difference of either 55 mm and 35. Or a difference of 45 mm and 25 mm. Yikes, that seems to be alot. Forgive me but I am used to thinking in inches instead mm. (When I need to do an inch conversion I visualize a 100 MM cigarette which is about 4 inches long. ) That is an error difference of about 2 inches. ( for 55 mm) Did I get the MM to Inches conversion correct? I hope so.
4. So things are out of wack. There are at least two issues. A up and down issue and then a left and right issue.
5. If you ask me there are two different areas that your problem is coming from. Either the 1 st mirror is the problem. Or the laser tube is not properly aligned to the first mirror/optics system. Actually there is a third possiblity of a combination of the first two problems.
6. So now what are you going to do? I think there are several different ways to help solve the problem but I am not sure which is best and most appropriate.
7. Did I read that you have had this machine for about 4 weeks? Was it new before that? Did you get it assembled or did you have to put the it together. Were there instructions or a how-to video? I agree with Walt. You need to get things back to some baseline corrected setup.
8. One last question. How much distance is there between the output of the laser tube and the first mirror?
Good luck and work safe. Lasers are dangerous. High voltage and damaging laser power. FanFan

[herby08]

hi guys
any up difference in hight from the tube exit to the first mirror is a question of the tube been to high and the pieces under the tube need to be removed and make sure the mirror #1 is max 25mm ( 1 inch) away from the tube end.
the side wise difference to mirror#2 need to be rough adjusted with the oval holes on the mirror#2 holder and the fine adjustm,ent only would be made with the setscrews on mirror#1 this takes a while to figure out how the screw adjustment works but it works.
the laser head will only be adjusted with the setscrew on mirror#2
you can move the beam with the setscrews about 50mm sidewise and 30 to 40mm hight wise in ether direction.
greetings
walt

"I replaced the mirrors because there was no spares with the machine and I accidentally burnt a hole in one. Now for the beam. It was not hitting the middle of the first mirror, so I had to adjust the tube. The beam is pretty good between the first and second mirrors. Between the second mirror and the laser head when the head is closest to the mirror and close to the tube the beam is 10mm left and 10mm high on the head. When it is in far away position the beam is 55mm left and 35mm high. Which is saying the mirror is not set at 45 degrees and I have tested it today with a set square and that is true it is not set right. I have taken the mirror set screws right back to test the beam in it's unadjusted position. This k40 machine build quality is poor and we have to completely reset things to get it working. "

Dom, thanks for you reply. Just so that we are on the same page. Before replacing the mirrors the laser was working okay, right? The test shot were coming out okay? They were centered? So things went a little wacky when the mirrors got replaced, right? Just checking, where did you get the replacement mirrors?

So back to the beam. If we follow the beam out of the laser:
1. It strikes the first mirror and it is pretty much centered.
2. It reflects off the first mirror and strikes the second mirror when the 1 st and 2 nd mirrors are close to each other ( as close as they physically can be.)
At this point on the 2nd mirror the test shot is postioned at 10mm and 10 mm, correct? You mean that the shot is centered, right? I am just making this point to make sure that I understand your point of view. ( I would call that spot 0, 0. but that is just a personal preference).
3. In my last post I mentioned moving 2nd mirror half the allowable distance away from mirror # 1. I am sure that the test shot dot must have moved off dead center, right. Do you know how much? and in what direction?
3. Okay , now you move the 2nd mirror as far as away from the the 1 st mirror and took a test shot. That one is off postion by 55 mm left and 35 mm high. Just so I know are those numbers referenced to 0,0 or 10,10 ? Either way there is an error difference of either 55 mm and 35. Or a difference of 45 mm and 25 mm. Yikes, that seems to be alot. Forgive me but I am used to thinking in inches instead mm. (When I need to do an inch conversion I visualize a 100 MM cigarette which is about 4 inches long. ) That is an error difference of about 2 inches. ( for 55 mm) Did I get the MM to Inches conversion correct? I hope so.
4. So things are out of wack. There are at least two issues. A up and down issue and then a left and right issue.
5. If you ask me there are two different areas that your problem is coming from. Either the 1 st mirror is the problem. Or the laser tube is not properly aligned to the first mirror/optics system. Actually there is a third possiblity of a combination of the first two problems.
6. So now what are you going to do? I think there are several different ways to help solve the problem but I am not sure which is best and most appropriate.
7. Did I read that you have had this machine for about 4 weeks? Was it new before that? Did you get it assembled or did you have to put the it together. Were there instructions or a how-to video? I agree with Walt. You need to get things back to some baseline corrected setup.
8. One last question. How much distance is there between the output of the laser tube and the first mirror?
Good luck and work safe. Lasers are dangerous. High voltage and damaging laser power. FanFan

[dominic gailgan]

Hi Walt

I can't get this machine set. The beam is now moving 14mm on the second mirror. It starts about 2mm off centre towards the laser head when the mirror is closest to the tube and when I move it to the front of the mirror the beam moves off the mirror and hits the mirror holder towards the left side wall of the machine. But there's no height movement. I have levelled and paralleled the tube. I made the second mirror sit at 45 degrees but it looks crooked in relation to the gantry. I have paralleled the laser head to the gantry and the second mirror. But after all this the beam still has a mind of it's own. I now understand why people complain so much about these small cheap Chinese laser machines. I really need someone in my city to help me but my question on the Zone for some local help has gone unanswered so far. I don't think I can get this piece of junk to work. I think it will work well as a boat anchor.

Thanks Dom

[Exsecratio]

the key is VERY small movements Dom, fractions of a turn on the screws etc...

It is a pain but Walt is bang on, until you have that 45 degrees on the first mirror you will be chasing your tail

I'm doing a cad drawing that will help but as I'm 10,000 miles away dropping round to help will be a tad of an issue

best wishes

Dave

[dominic gailgan]

From the problem we are having my wife and I think it's either the tube is not parallel or the first mirror is not set at 45 degrees. Because when we move the second mirror the beam is moving away from the the laser head towards the side wall of the machine. So we have to fix that problem.

Thanks Dom

[dominic gailgan]

Hi

Ill ask the stupid question now. How do I make sure the tube is absolutely parallel to the gantry? Because I'm obviously not doing that measuring wrong and the tube is not parallel.

Thanks Dom

[dominic gailgan]

Did some more fiddling this afternoon and I found that the first mirror and the second one are not parallel to each other. The second one is closer to the side wall then the first one is. I would assume that would stuff up the beam path. Also Walt you said the first mirror must not be more than 25mm from the tube, it is ok. So should I shift it?

Thanks Dom

[dominic gailgan]

Thanks to you kind people on this forum we now our machine going. But we had reset everything. We had to parallel the tube to the gantry, set its distance to the first mirror as it was too faraway. We had to set the angles of both mirrors as they were not set at 45 degrees. We had to shift the second mirror as it was not in line with the first mirror. The laser head had to be paralleled to the gantry and lined up with second mirror. But after all this was done our machine is engraving which is what we wanted it for, no cutting just engraving.

Thanks Dom