We’ve been using diode lasers for a while now but this OMTech K40+ is our first C02 laser and this is on a whole new level. We’re engraving super fast and we’ve been able to easily cut and engrave on glass and clear acrylic which we have struggled to do in the past with our diode lasers.
BUT… there is quite a big learning curve. You have to factor in cooling or heating because this machine uses a water pump. And you also have to contend with mirror alignment which makes this machine more complex than your simple diode laser. Having said that the mirror alignment is quite easy to do and the manual has full instructions on how to it.

So is the increased power and speed worth it? Let’s take a closer look
First up, the machine itself is really well constructed – it feels very solid and looks like it will last a lifetime.
Given it’s size and weight you’ll more than likely need two people to lift it, along with having a sturdy workspace to support it.

Where Can I Buy the OMTech K40+?
Here is the link to the K40+ (affiliate link). Use code GLGAU
What’s in the box
In the box are a variety of extras including:
- cables
- a USB stick
- tape
- a manual
- exhaust pipe
- water pump
- a honeycomb bed which is nice to see. These aren’t always included when you purchase a laser machine.


The K40+ has a removable tray to easily allow you to remove any debris.

Work Area
The work area measures 8” x 12” so it’s a decent size to work with for most small to medium sized projects.

Setup
Setup actually wasn’t as bad as we were expecting. The machine came fully assembled and we just had to attach the venting pipe to the back of the machine as well as set up the included water pump. This is needed to cool the laser tube during operation as it generate a significant amount of heat while in use.

We had to find a reservoir of some sort to hold the distilled water that it requires and we ended up using a plastic container.
Now as we live in an area that is pretty cold right now so we purchased a Sous Vide to heat the water up to the required minimum temperature of 15 degrees celsius (60F).

When it starts to heat up here we may need a chiller. OMTech do sell them so keep that in mind if you are going to purchase one of these machines.

Laser Currency Function
One thing that was completely new to us was the Laser Currency function on the machine. We actually had no idea what that was or what to set it at.
However, we did find a video by the Louisiana Hobby Guy who said that you shouldn’t run your C02 laser at more than 70% power and he shows you how to set the machine so that you don’t exceed that.
So basically we had to turn the Laser Currency dial as far left as possible and then while the machine was engraving a small rectangle, we turned the dial to the right until the AmMeter reached 18 which equates to approximately 70% power.

The manual actually says to run the machine at 100% but in another part of the manual it says that it can shorten the life of the tube.
So we were a bit conflicted here but we decided to follow Rich’s advice to keep the machine at 70%.
Mirrors
It’s worth noting that this machine works with mirrors to direct the laser beam from the laser tube to the cutting or engraving surface.

Now whilst the manufacturer aligns these mirrors prior to shipping, they can shift during transit but it does explain in the manual how to test if your mirrors are aligned and it was pretty simple. It just involved a bit of masking tape and pressing the test button a few times.

Here are some helpful links if you need help with aligning the mirrors.
HELPFUL LINKS
- Laser Mirror Alignment (Edmonds Workshop)
Inbuilt Exhaust Fan
The machine comes with an inbuilt exhaust fan and air assist which is a nice to see as apparently the previous model did not have this feature.

Safety Features
In terms of safety features, the machine has an automatic stop button which you can press in emergencies and the lift up lid has a shut off feature which cuts power to the laser if it is opened.
However, when you do this, although the laser stops firing, it continues to move which seems odd. So basically your project is ruined and you have to start from scratch.
My preference would be for it to pause as soon as the lid opens and then restart when it is closed but then again I guess you shouldn’t be opening the lid.

The lid itself has a nice protective shield which is apparently flame proof although it’s pretty much impossible to see inside to see what is going on inside.
This makes it difficult to see how your project is going.

We ended up attaching a GoPro to the inside and connected a Black Magic screen to it so we could check the progress and also film for this video. Not ideal but it worked.

Lightburn
Now, this machine does work with Lightburn and it connected quite easily although we did have to install a driver first which you can find on the included USB stick.

Projects
PLEASE NOTE: THE FOLLOWING PROJECTS ARE OUR FIRST ATTEMPTS. BE SURE TO RUN A TEST BEFORE COMMITTING TO YOUR PROJECT.
Okay, so let’s take a look now to see how well it cuts and engraves.
And as usual, we started with some MDF coasters and just like with our diode lasers, we had to focus the laser head.
They include a small piece of plastic to do this but I would have preferred a block shape. Being so thin, it can easily fall over when you are trying to focus so I will be looking for an alternative to this.

MDF Coaster – 1
The coaster came out great. It’s not perfectly centered and we should have made the image larger to fit the coaster but I really like the depth of the engraving.
Image File – Creative Fabrica
- Speed – 100 mm/sec
- Power – 10%
- Fill
- Time Taken – 8mins 21 secs

MDF Coaster 2 – Engraving and Cutting
For this coaster we engraved the design and added a border in Lightburn. We rounded the corners to give the coaster a nice finish. Once it had finished engraving we cut it out.
I really love the image that we found for this one.
Image file – Creative Fabrica
Engraving
- Speed – 100 mm/sec
- Power – 10%
- Fill
Cutting
- Speed – 5 mm/sec
- Power – 20%
- Line
- Time Taken – 14mins 45 secs

Wood Coaster
We then moved on to a wood coaster and this also came out great and quite fast compared to our diode lasers. With our diode lasers we’d be looking at around 8 to 10 minutes to engrave something like this.
Image file – Creative Fabrica
- Speed – 100 mm/sec
- Power – 20%
- Fill
- Time Taken – 4mins 45 secs

Slate Coaster
And keeping with the coaster theme, we then tried a slate coaster. We used a file from Creative Fabrica – our go-to for laser files.
Image file – Creative Fabrica
- Speed – 100 mm/sec
- Power – 20%
- Fill
- Time Taken – 6mins 40 secs

Ceramic Tile
For the first time ever we managed to engrave on a ceramic tile. We have tried this previously on a diode laser and had no success with it. This came out great although maybe the settings could be increased a little more to make it a little more intense.
Image File – Creative Fabrica
- Speed – 125 mm/sec
- Power – 20%
- Fill
- Time Taken – 6mins

Clear Acrylic
One thing we were really exited about trying is clear acrylic which we have had zero success with on our diode lasers.
These worked extremely well. We didn’t have to paint the acrylic or use any other type of masking. We just popped the clear acrylic sheet into the machine and away it went.
You can see the first one is not so perfect but after adjusting the settings just a little, the second one came out great.
Image Link – Creative Fabrica – Tis the Season
Image Link – Creative Fabrica – Winter Wonderland
- Speed – 275 mm/sec
- Power – 20%
- Fill
- Time Taken – 3mins 40 secs

Black Acrylic
We also tried some black acrylic and this did a nice job. Bear in mind that we just guessed the settings on this one so I think with a bit of tweaking we could improve on this.
And just for a comparison on speed, we did this coaster pattern some time back on the xTool F1 and it took about 25 minutes. On the OMTech K40+ it took 8 minutes 40 seconds.
Image File – Etsy
- Speed – 5 mm/sec
- Power – 100%
- Fill
- Time Taken – 8mins

Glass
Our final test was on glass, something we’ve never had much success with our diode lasers so we weren’t sure what to expect with the OMTech
So to be honest, we didn’t put much effort into it.
We just placed a shot glass on the bed and created some simple text in Lightburn and we didn’t even bother to frame it properly.
So we were pleasantly surprised with the result and super pleased with our first successful attempt at engraving on glass.
- Speed – 150 mm/sec
- Power – 20%
- Fill

Cutting Wood
Now OMTech do state on their website that this machine can cut up to ⅛” thick but for a bit of fun, we wanted to try some thicker wood although, we were really pushing it here with a ¾” piece.
We started with 1 pass, then 2 and then eventually 8. You can see the results here.

Final Thoughts
Okay, so what are our final thoughts?
Pros
Well first of all, we still have a lot to learn about using this machine but it is our first C02 and we did have a bit of a learning curve.
- The machine itself is solid and built like a tank so no problems there.
- It was easy to setup.
- It’s fast – things that would take us 25 minutes to engrave on a diode laser took us less than 10 minutes on the OMTech K40+.
- You can also engrave materials that would be difficult to do on a diode laser like clear acrylic and glass. This is a big plus for us.
- The price is fairly reasonable at under $700 in the US or under $1000 in Australia so it’s a great entry level C02 machine.
Cons
- This laser is heavy so you will probably need two people to move it around and a solid surface to hold it.
- You’ll also need access to the back of the machine at times to adjust mirrors or to check the laser tube. So be mindful of where you place it.
- Adjusting the mirrors can be a bit fiddly. However, there is a video on the USB (included with the machine) that takes you through the process. I’ll also add what I thought was a very helpful video tutorial in the description field below.
- The safety lid is great at protecting your eyes but you can’t see through it which means it’s really difficult to see what’s going on. This is why we set up a camera and a light inside the machine.
And as I’ve already mentioned, there is a bit of a learning curve to this machine but it’s well worth it if you are wanting to try out a C02 machine for the first time at a reasonable price.
Hello.
Great video, thanks a lot.
I have a big issue with my K40
All well setup..mirrors and focus…but engraving photo on clear acrylic is really poor quality compare to what I used to get with my 5w diode laer and black paint.
Any idea, help will be greatly appreciated.
Regards
Are you using extruded acrylic or cast? If you use extruded, it won’t look good.