Help with aligning MIRRORS

[Brooke Kim]

Hi guys,

I am a newbie so please be gentle. I have been hunting the forums for about a week and cant find what im after.

I have just purchased a 60w laser machine and have it to the stage of adjusting the mirrors. We have been working on the mirrors for a few days and it is driving us crasy, I have read it is hard at first but once you know how to do it it is easy, well I hope this is true.

We can get the 1st laser to go into the center , but not up high enough (it falls just below the middle) we have adjusted and adjusted but still nothing, What to you guys think could be wrong?

Im thinking the ground is not level and this could be causing the machine to be off a little.

does anyone know a link where there is a video of how to align the mirrors as I cannot find one anywhere and the manual I got with it is pretty basic (actually amazed we got this far with it)

Thankyou in advance

[Mike Null]

Brooke
It would help to know what kind of machine you have. We have some tech support people who monitor the forum and who could help you. If you purchased one of the better known brands your sales rep should have done that during installation.

If you've purchased one of the Chinese machines we have a couple of people who have them as well and may be able to help.

[Brooke Kim]

Hi Mike,

We have brought a Chinese one ($4000 compared to the $40-$50,000 price tag here in Australia for a brand name the same size) The company are very helpful concidering the langage barrier, as they have helped us during the installation process etc, as our software was not correct and they got that all fixed up, anyway any help would be appreciated (Im a bad speller so please excuse it)

[Brooke Kim]

UPDATE

i figured out that the laser beam needed to be adjusted a little to get to the center of the mirror (move slightly upwards) which worked fine and 1st mirror is smack bang in the middle

then i aligned the second mirror and this too is in the middle, but when i do the y and x test, the y axis is not matching up, only the x axis, am i missing doing something? or should i start from scratch
how do i correct this? do i have to move the mirrors again, which one

I know that it is a hard procedure to explain, but any help would be better than none

thanks

[Rob Bosworth]

Brooke, I do not understand what you mean by " but when i do the y and x test, the y axis is not matching up, only the x axis." Please explain what you did and why.

[Brooke Kim]

Hi Rob,

ok when we do the test, the manual tells us to do a y and x test on the second mirror, after we have the laser hitting the center on both 1st and second mirror.

the y (upper left corner and lower left corner) do not burn in the same place on my test tape on he second mirror, but when i burn the upper left and upper right they are matching

now I was in bed not sleeping all night thinking we must be doing 1 of the steps wrong, now just figuring out which one. I might hunt for a manual online that explains it better :confused:

also the machine is a LG1200, forgot to mention that before and also forgot to mention that i am not a tech machine guy, I know nothing basically, so if you think im a idiot that knows nothing, he he i know i am :D

thanks

[Gary Hair]

Brooke,
I have advise for how to correct your problem and this might help you visualize what is going on.

Basic refractive principles state that the angle that light hits a mirror is the same angle it leaves. Same thing when you are playing pool. It the light/ball hits the mirror/rail at 45 degrees, it leaves at 45 degrees. That is why when you are at upper left or upper right the burn mark is in the same spot. It moves at lower left and upper left because it is coming off of one of the first two mirrors at something other than a 45.
My guess is that if it is higher in the lower left than it is in the upper left, it should mean that the beam is hitting the second mirror at too flat of an angle and you would want to adjust the beam toward the back of the machine. I don't know if this makes sense but I can picture it very clearly in my mind - that's a scary place so best not to go there...

If this doesn't make sense, I'll draw a picture and post it - let me know.

Gary

[Brooke Kim]

Hi Gary,

thanks for that info, it sounds spot on, i think i understand it

Im going to try to do it on the weekend when i get some time, so ill let you know how i go and if i need the picture,

thank gary fingers crossed

[Brooke Kim]

Hi Gary,

ok mirrors are now alligned, 1 whole day later and a great dad who came to my rescue (what would we do without them)

anyway we just have to adjust the focus lense on the arm,
ill let u know how we go, ran out of time on the weekend, so im gonna get dad to help this weekend

thanks again
Brooke

[Gary Hair]

Glad to hear it is going well Brooke!

Gary

[Brooke Kim]

Gary i need your help again, hehe sorry

the machine is not cutting all the way through on the first cut on a piece of 3mm perspex. when you look at the edge of the plastic after it has been cut you can see a slight angle - its not a straight cut, slightly angled to the left at the top of cut (best way i can discribe it)

now do we adjust the focus lens or the 3rd mirror. We dont want to mess with it much more until we figure out which one to adjust

any help would be great

oxoxo

[Gary Hair]

An angled cut would almost certainly mean a mirror needs to be adjusted.

It could actually start with the first mirror being out a bit and carrying that misalignment all the way through to the lens. It's possible that all you would have to do is adjust the 3rd or 4th mirror, but it's also possible that you may have to start at the beginning. Any misalignment at the first mirror will only get worse by the time you reach the lens - you've got to start out dead-on.

Check where the beam hits the lens before you change the 3rd/4th mirrors. Remove the lens and put a piece of tape over the hole, closest to the bed (not on top of the lens opening). Test fire the laser to just burn a spot on the tape. Ideally this should be in the center of the lens opening. If it is not then you can adjust the 4th mirror accordingly. After this adjustment you can check the cut again to see if it is perpendicular to the bed.

If the cut slants to the left in all 4 corners then you need to adjust the point the beam hits the 4th mirror up just a bit. This should move the top of the beam to the right and the bottom to the left. Make sure you check all 4 corners of the bed before you make any adjustment though, you could make it a lot worse than it is now.

Good luck!
Gary