Laser alignment

[Bert Kemp]

an observation Looks like your pushing the tape into the mirror, if thats the case make sure and dbl sure you clean those mirrors before trying to use the laser or you will be replacing mirrors real quick.

[Chris Clayton]

Hey Bill, thanks for that. That makes perfect sense. I did check the gantry and rails to make sure they are 90 degrees but I'm going to buy a digital protractor/angle finder to be more accurate and also use a dial gauge to check the basics before I mess with the mirrors any more.

[Chris Clayton]

an observation Looks like your pushing the tape into the mirror, if thats the case make sure and dbl sure you clean those mirrors before trying to use the laser or you will be replacing mirrors real quick.

Very true. Once alignment is done I'm going to recommend we get new mirrors and a lens. I haven't mentioned yet that we should get a bigger compressor and air dryer to keep the Houston humidity off the lens. Baby steps haha

[Bill George]

Very true. Once alignment is done I'm going to recommend we get new mirrors and a lens. I haven't mentioned yet that we should get a bigger compressor and air dryer to keep the Houston humidity off the lens. Baby steps haha

Nah, just clean the mirrors with DNA. If you run A/C and keep the shop cool your air compressor will not have as much water in the air lines. I do also have an refrigerated air dryer, but my laser just uses a fish tank air compresser so I don't need.

[Joseph Shawa]

If you get same tight spots on mirror 3 left and right in different Y positions then your right rail is not level.

[Chris Clayton]

The thing that confuses me is that x-axis will be centered when closest to me, then move lower left at mid-machine, then jump UP as it nears the back right corner. Then I move gantry back to me and instead of being centered like it was 20 seconds before, it's now lower than center. A gradual up or down I could handle and I'd know the rail just needs to be raised or lowered. I hate this thing but at least after figuring it out, I'll be able to make my own laser in the future haha. I'm looking at ways to make sure the rails are co-planar/on the same plane/whatever the word is. I'll keep checking in and write an update after looking at it on friday. Thanks people

[Dave Sheldrake]

Align the output of the laser tube optics with the hole in the laser head,making sure it is parallel with the gantry bearing, then work back from the head on the mirrors

[Rich Harman]

Hey Bill, thanks for that. That makes perfect sense. I did check the gantry and rails to make sure they are 90 degrees but I'm going to buy a digital protractor/angle finder to be more accurate and also use a dial gauge to check the basics before I mess with the mirrors any more.

The easiest way to check for the Y axis being perpendicular to the X axis is to have the laser draw a large square, then measure the diagonals. If they are equal then it is square.

[Joseph Shawa]

Never mind.

[Chris Clayton]

I wasn't able to make it to the shop today. When I look at it again, I think I'm ripping off the right rail to see if it's twisted or bowed. Thinking about it, if the rail was higher in the center and then sloped back down, that would cause the beam to hit the 3rd mirror lower in the middle of table and then higher as it goes towards the back right corner. Really appreciate you guys and I'll be back within the next few days. Have a great weekend!

[Phil Berch]

Hi Chris,
I am about to align up the mirrors on our omnisign plus 50 watt laser. have a look at these two video's they may help
https://www.youtube.com/watch?v=5YvOqH44n6c&list=PLeKaKWOIPgi_XP6Nxzeapp-vUMCLQyVMB&index=65

https://www.youtube.com/watch?v=pl6dAWOkksM&list=PLeKaKWOIPgi_XP6Nxzeapp-vUMCLQyVMB&index=66
Phil

[Mike Lysov]

ok so I'm going to see if I can add some images.

Thanks again guys!Attachment 364574Attachment 364575Attachment 364576Attachment 364577

Is it what you have now? I can try to explain what is wrong if you can show me results from the following test

1)fire at the mirror #2 at its closest position to the mirror # 1 (lets call it Y1 burn spot) and at its farthest position from the mirror # 1 (lets call it Y2 burn spot)
If both Y1 and Y2 marks land on the mirror #2 it is good. It does not matter if it lands on the centre of the mirror # 2 or not as long as the Y1 and Y2 somewhere on the mirror # 2
2) using adjustment knobs on the mirror #1 bring Y2 burn spot exactly to the centre of the mirror #2
3) Now if you do another Y1 and show it to us it should be quite easy to tell what you will need to do.

You may have rails unsquare or may be it is just the mirror # 1 holder is in the wrong spot or the mirror # 1 sits in its holder at the wrong angle. It may be even all of these problems together at the same time. However to see what you will need to do to align it you will need to do these three simple steps above first.

[Kev Williams]

Before I'd tear off any rails to see it they're bowed, I'd measure the rail, then go to Harbor Freight and pick up one of their $4 aluminum rulers that's just a bit shorter (or hacksaw off a longer one, as cheap as they are). The rulers edge will be flat enough to check your rails straightness without removing it...

[Mike Lysov]

I would not touch rails at all at this point. It is very likely that the mirror #1 holder is just in a wrong position and rails are ok. So if that's true and you start playing with rails you may create a nightmare for yourself where you will have both optical and mechanical problems.

The first mirror that sends a beam from a tube along Y axis is very important for a beam alignment. If it is in a wrong place, has a wrong angle in relation to a beam plane coming from a tube you will never align a beam.

The steps I have described above will help you to see if a beam travels along Y perfectly. If it is not it is most likely to be a problem with the mirror # 1 set up wrong. Adjusting its position by moving the mirror holder you can set it up absolutely perfectly at least for the close end and the far end of Y.
If Y rail is bent it will be obvious once you start to move for the far end to the close end or in other direction but at least you will know it is bent because you can be sure you have aligned both ends of the rail with a beam path.

[Bill George]

I go along with Kev, check the rails and the frame for square first. Pretty simple, if their off needs to be corrected first. With a normal quality laser its normally not an issue but this a cheap or perhaps damaged machine.