eBay Chinese CO2 Laser Cutter & Engraver - Advanced Mirror Alignment Jig Part 1

[@Georg-fb8iu]

To square an XY gantry you have to measure diagonals. Once the two diagonals are of equal length, you are 100% square.

[@DIY3DTECHcom]

Yes you do that, as I set up a target and used a laser (small one) to measure the rise and run...

[@Georg-fb8iu]

BTW, I found out that one can use laser distance meters (used in construction) to measure small distances. They are pretty precise. I used one of these to square my CNC router.

[@DIY3DTECHcom]

Interesting the ones I have seen are pretty large, how big was the CNC?

[@cattaraugustonawanda4426]

You should be aligning your laser to each axis in sequence. Your idea of using a visible laser to align is workable but you need to align with the visible laser on the same axis as the co2 laser. Make a simple mount that attaches the visible laser or to the glass tube. Fire the co2 laser on the paper target, and mount the laser to determine exact position of the visible laser. Remove the paper and run use the visible laser to adjust the first mirror, second mirror, and third mirror using targets. Would be easier to show than put into words but you need to shoot your visible laser in same alignment as the co2.

[@DIY3DTECHcom]

The issue is it would have to be in align with the tube and the room was not there...

[@jpodius]

Thanks for the info. One thing I don't understand is how to ensure the first mirror is exactly 45 degrees to the cutting laser (sothe jig mirror is perpendicular). It seems that moving the gantry without that mirror being exactly 45 degrees would cause the same left/right drift that having the bed out of alignment would cause? Adjusting the bed to then match that would only compensate for the first mirror being not exactly 45 degrees?

[@DIY3DTECHcom]

The short story is its hard. However if I follow you, you correct about the run out. So the first thing I would level & square the Bed/Gantry. Next I square second order mirror on the X gantry with the lens mirror assembly. There are several ways to do this and I use visible laser which I squared off then I squared the first order (the one facing the tube) and then adjusted the tube (with the custom brackets I 3D printed) align everything. Now this was not perfect (as I did have to adjust the first order mirror as I could not adjust the tube enough because of the enclosure). Hope this helps :-)

[@jpodius]

This helps immensely, thanks!

[@pedroreynoso793]

is there a way to edit the laser holder to be used with a 6 mm laser?

[@DIY3DTECHcom]

Not not off hand without a redesign...

[@jaimiflores3809]

This is great, so helpful and informative. We are able to get our mirrors so that they align horizontally, but it shifts vertically and the power of the beam dies down the further the cutter head is from the mirror. We have measured the bed and it is set perfectly. I have tried to adjust for the vertical difference but then the horizontal alignment is off. We are at a total loss and would appreciate some guidance on how to determine the issue and go about fixing it. Thank you.

[@DIY3DTECHcom]

So first things first, the more air the beam hits (being 10,600nm which is really long) will attenuate the beam and its a fact of life at this wave length so do not expect it to be equal close up as well as well far away. Also Did you see the video in my play list for the CO2 laser where I had to 3d print a shim for level out the gantry vertically? Also look at the video with he new 3D printed clamps for the laser tube as your tube could be crooked too...

[@MarelizeBester]

This is great, thank! How would you align the 3rd mirror? My laser seems to not point down straight into the head? The mirror only has a slide bracket, not any adjustments screws like the other two.

[@DIY3DTECHcom]

One of the things you need to do is ensure your tube is level also, please see the video in the playlist where I did the 3D printed tube clamps as you have to think of your entire optical train floating in 3D space as that us how it work on expense lasers. Hope this helps and if just ask :-)

[@Henchetarian]

Please correct me if I'm wrong but I have had similar problems like you have with this and solved by moving the position of the mirror, then changing the angle. I believe if you had moved the mirror slightly closer (or maybe further away) to the laser then you could have got it to shoot straight down the line of the rail. Are you not able to move mirror position?

[@DIY3DTECHcom]

+patrick whelan The issue is my gantry (and most likely most peoples) was not square in the sheet metal and the sheet metal case on top of that [also] is not square. So with all of that said, you can keep trying to adjust he mirror however if the plane in which you are trying to square is not square itself you are simply robbing Peter to Paul. If you look at the expensive units, you will notice they have an internal skeleton which locks the laser tube and all all mirrors into the same plane providing a unified beam to all locations of the bed. 3D Printing that shim made a huge difference in allowing me to proper achieve alignment across the extended bed. Note I also moded the bed so I can cut like 9"x10" material. If I was doing just what fit in the clamp or there about this would not have such a big issue.

[@Henchetarian]

Thanks for your answer! Yeah I thought that there was a bit more to it than I assumed.My machine is quite different from yours, I think your videos are really interesting by the way! :) What you achieve in this project is very nice alignment, so satisfying to see the difference! Its like a good shot in pool :)

[@h4z4rd42]

Why would you measura anything from the sheetmetal casing? It is pretty obvious you should use the Y-axis rails as reference. First check if rails are the same level and parallel with each other, -then check if gantry is in a true angle with the rails -then align tube parallel to gantry -then measure if tube is horizontal at the right vertical level where it hits the centre of mirror 1 -mirror1's height must be equal with the head's entry point (from the rails obviously) -align mirrors -done

[@DIY3DTECHcom]

Ugh, because I can? There are things in the world such absolute (which this is not) and relative (which this) measurements and the later was used approximate the tubes general orientation in 3 dimensional space which worked well. As I did this quite sometime ago I can't remember all the pieces, however you will notice in the playlist I have designed and 3D printed replacement tube hangers as one of the most critical things IMHO is the tube needs to be aligned relative to the optical train. Hope this explains :-)

[@h4z4rd42]

Sure it does. :) That's why one should pick a reliable reference point or plane. I've just went trough an overall alignment procedure on my (60x90cm work area) machine and figured out the baseplate under the tube is off level by 2mm compared to the Y-axis rails vertically at the tube mounts, and the side casing is almost 3° off horizontally. Took me a while to figure out why I fail to aling it properly. For the record, we are dealing with chinese machines...

[@DIY3DTECHcom]

Trust me I get the Chinese machine part! However you get it as most miss this point about the level of the tube, this one of the biggest questions I get and try to explain that in high end machines the optical train "floats" rather than being affixed to a sheet metal frame as everyone says "you can just adjust the mirrors" to which I share if your adjusting the mirrors you have an issue...

[@BrookeHedrick]

Hi! I am really enjoying this video series on the adjustments. Have you had a chance to put the alignment laser holder design on Thingiverse?

[@DIY3DTECHcom]

+Brooke Hedrick Glad your enjoying and apologies don't think I did however here is the Tinkercad link (tinkercad.com/things/ecUVKmhVvkg) and for the 5 volt lasers here is also the eBay link (goo.gl/ypUD1c). Let me know how it works out as this whole alignment really made a huge change in the abilities of my machine! Cheers, Joe...

[@axonz31]

So I've got mirror 1 and mirror 2 aligned. When I do the Y test to double check, they are off about 1/2". What could this be?

[@DIY3DTECHcom]

Not sure what a "Y" test is however check both the level of the tube to the mirrors (not the metal enclosure) and also check the gantry as mine (i.e. gantry) was off about 1/4". This also why I 3D printed new tube "adjustable) tubes holds too and there is video on this in the laser play list as well as the STLs on Thingiverse...

[@owpeterj]

@@DIY3DTECHcom Still looking for that but not by the time you read this. It would have been easier to get a laser head for the CNC 6040 which I now have - Haha, alignment is a serious affair - one might have hoped it to be fine on delivery - that said however, clever chaps (haha) like yours truly will often 'fix' things - the wonky sheet plate bed, the ridiculous sized bed, so goodness, if it anyway doesn't go out of alignment. Only then does one realise how unreferenced the thing is screwed together. Measuring isn't easy - continuous laser tests risk mistakes. Anyway, I'll make the most of what you have to share and hope that if one day I actually have it in use and some time for 'social platform' awareness, it'll become apparent as to how much I/we all appreciate the sharing from others on subjects which are of practical relevance to me/us. Have a good one mate and thanks for your whole time and setup to share.

[@scottgardner960]

I agree with H. Measuring anything from the casing is completely irrelevant. If the x and y axis rails are rectilinear then the casing could be the shape of a blancmange and have no effect on performance.

[@DIY3DTECHcom]

It act as a referance point...

[@jbrondos]

1) Do you have to align the laser tube itself before adjusting the mirrors? 2) Have you ever seen documentation which describes what can be expected by turning each of the adjustment screws? Trial and error with each of the three set screws being turned clockwise and counter clockwise is rather time consuming and frustrating. I apologize if I missed it in any of your other videos or notes. You have so much good material (so many thumbs up . . . )!

[@DIY3DTECHcom]

You must (should) align the tube "with" the mirrors. Think of the optical train as "one" unit so a change in one pieces is a change in the total train. Also no to your question #2 however after investing a few hours of doing you will get use to it. As to get a really good first align will take a couple hours...

[@matjazstrnisa]

Where we can buy this tools for aligment? (Led and this parts)

[@DIY3DTECHcom]

These are just 3D printed pars and got the lasers off eBay (they are common pointer lasers)...

[@karensmith5510]

Do you have a link to your jig. I couldn't find anything on thingiverse

[@DIY3DTECHcom]

Sure here is the link: www.thingiverse.com/thing:2240686

[@karensmith5510]

I clicked on the link it takes me to thingiverse, Customiziable Plastic Cleanup & Finishing Tools!, not to the Advanced Mirror Alignment Jig

[@DIY3DTECHcom]

Wow thats going back a ways! Thought you where asking about my newest video, however what your looking for is here www.thingiverse.com/thing:1149832

[@sotm6078]

Do you have a Thingiverse for the red dot laser holder?

[@DIY3DTECHcom]

I don't think I ever put this one out there as I did like it that much, however you seach under my profile as I think I am well over 100 models out there now so I cant keep track any more...

[@muserbellamy1140]

Good explanation although MMs is more accurate

[@Dean-Sala]

This info that your provided here with the K40 laser is priceless. Too bad I did not find your video earlier. I had to do to pretty much the same with my alignments. Gantry adjustments as well. And it took me many grueling hours to get is right. I actually had to take material off the secondary mirror bracket to move it to the right to align parallel to the primary mirror . I am very relieved that someone had the same issues with alignment as I did. But once aligned, this freaking laser works very well. I figured the labor required to calibrate this thing makes the difference between a $400 laser and $5000 laser. Time is money. This laser definitely requires an experienced hands-on engineer to figure it out. Including the software. Laser SafetyMy laser safety experience first hand:I love having a CNC laser. It is the coolest thing I have ever had in my shop besides my CNC machine. But it is unfortunate that China can get away with selling these lasers so cheap to the untrained person. Imagine an ignorant teenager getting their hands on one of these for a Christmas present!Get used to the laser zapping you every now and then if your fingers get into the way of the beam. You will know it when it does mostly during alignment procedures. I am sure owners know what I am talking about. Having the lid open is more desirable in some cases but use safety glasses. I took a look at the cutting light without laser glasses while running a job and it made a dot in my eye for about 30 minutes. I thought that I would have to live with this for the rest of my life but it went away. Just be careful. These are a new bread of tooling that is available to us hobbyist and small business owners. High powered lasers require more respect than most other tools you may have in your shop. And this is mostly about danger to your eyes. If you are working with reflective materials be very careful. All in all I love this thing but I do very much respect it. Dean SalaSuntactics

[@DIY3DTECHcom]

+Suntactics you are 100% right! These are VERY dangerous and many people do understand that as not only to them selfs but people and pets in the area! When using mine, I make sure the room is clear and closed. Even the reflected light is dangerous! On the 25th & 29th of the this month I have several in the que where I record the cutting with my inferred camera!