OMTech K40+ Review by An OMTech User

The K40+ desktop laser engraver is one of OMTech’s most affordable and compact laser machines. As a seasoned laser enthusiast, I’ve been through my fair share of laser engravers over the years, and the K40+ actually beat out my expectations. For a $659.99 laser engraver, it works surprisingly well, assisting me on projects like engraving wood or cutting acrylic. 

Fast-forward a couple of months, and I’m ready to share my experience with the K40+. In this review, I’ll walk you through my journey with the K40+ 40W Desktop CO2 Laser Engraver and give you some tips and tricks on how to get it working properly. I’ll also show you the pros and cons of the device so you can decide if it’s the machine for you. 

K40 vs. K40+ Desktop Laser Engraver 

The OG OMTech users will remember the original K40, which definitely needed some improvements. The limitations with the fixed laser head and solid workbed left much to be desired, so the upgrades on the K40+ take this machine to the next level. Here are some of the main differences that make the K40+ leaps and bounds better than its predecessor: 

New motion system and laser head

OMBefore, the K40 featured a fixed laser head and a plastic wheel motion system. Now, the K40+ utilizes a new gantry and linear guidelines, along with a manually adjustable laser head that can improve focus and precision. 

Built-in honeycomb bed

OMTech’s addition of a removable honeycomb bed in the K40+ makes cutting and engraving jobs even easier. With the detachable bed and debris drawer, cleaning after projects is super simple. 

Air assist 

The K40+ offers air assist, keeping your laser engravings free of smoke and debris while decreasing the chance of fires. This function helps you achieve optimal results for your cuttings and engravings and ensures peace of mind for the safety of your machine. 

Digital Ammeter 

Unlike older models, the K40+'s digital ammeter gives more accurate readings when measuring the output of the laser tube. Using the provided digital ammeter, you can easily calibrate your laser power settings. 

Upgraded Motherboard

The upgraded motherboard now supports Lightburn (lucky for those Lightburn fans!), making the K40+ compatible with more laser engraver software programs. 

Unboxing and Initial Setup

The K40+'s unboxing experience was straightforward and well-organized. You can take the machine right out of the box and get started pretty quickly. Upon opening, you'll find the water pump, air assist pump, exhaust fan, and various accessories neatly packed inside the cabinet. The machine comes mostly pre-assembled, which is a big plus for those new to laser engraving.

One of the first things you'll notice is the sturdy construction. The K40+ features a robust metal frame that ensures stability during operation. The 9" x 18" flame-resistant viewing window is a standout feature, allowing for safe observation of your projects in action. The K40+’s removable drawer and honeycomb bed are a great new addition, making jobs more convenient and versatile. 

Setting up the K40+ is a breeze. Here are the steps to take to assemble your K40+ laser engraver: 

Water System Setup

• Add distilled water (15-21°C) to the water tank, maintaining at least 2 gallons
• Install suction cup and outlets on the water pump
• Connect blue hose from machine to water pump, submerge pump in water tank
• Place the return hose in the tank for water circulation
• Connect water pump to power supply
• Check for air bubbles in the laser tube. Tilt the machine if necessary to remove them

Exhaust System Setup

• Use the clamp to connect the exhaust hose to the fan outlet on the machine
• Place the other end outside or connect to an air purifier or filtration system

Electrical Setup

• Use a grounded three-prong socket or proper grounding cable
• Connect the main cable to sockets and grounded power source

Initial Tests

• Turn on the machine, check for pressurized air from laser head nozzles
• Test the emergency stop button functionality by turning on the machine using the key and pressing the button. The entire machine should turn off.
• Run the water pump system to check the water protection signal on the LCD display. Then, close the cover. The “water protection” should be ON.

Software Setup

• Install Laser GRBL software and CH341 driver on your computer
• Connect the computer to the machine via USB cable
• Set machine parameters in the software

Pre-Operation Checks

• Verify water levels for your water pump and ensure the water is flowing through the machine 
• Ensure the ventilation system is working
• Adjust laser power (start at about 15%)

Laser Alignment

• Attach a piece of tape to the third mirror over the laser head. 
• Move the laser head to the upper left corner of the workbed and press the red test button. Repeat these steps in each corner of the workbed. 
• The laser should burn the tape four times. If the optical path is aligned, there should be one mark on the tape. 

Focusing the Laser

• Start with a piece of material on the workbed. Loosen the locking screw on the laser head and place the focal ruler between the head and the material. 
• Manually adjust the height of the laser head so it touches the top of the ruler. 

Test Engraving

• Import the OMTech logo into Laser GRBL software
• Set parameters for engraving on a wooden board
• Perform test engraving

Additional Notes

• For thick materials, remove the drawer and honeycomb board
• Always adjust focus distance after placing new material

Specifications and Features

The K40+ boasts impressive specifications that make it a versatile tool for beginners, hobbyists, and small businesses:

	K40+ Laser Engraver
Power	40W CO2 laser tube
Working Area	8" x 12" (200mm x 300mm)
Max Engraving Speed	300 mm/s
Compatibility	LaserGRBL, RDWorks, CorelDRAW, AutoCAD, Lightburn
Operating Systems	Windows, Mac, Linux
Connectivity	USB
Positioning Accuracy	±0.02 mm
Max Engraving Depth	0.12 inches (3mm)
Cutting Capacity	Up to 1/8" (3mm) acrylic, plexiglass, or basswood

One of the standout features is the detachable honeycomb workbed, which provides excellent support for materials and helps prevent backscatter. You can also remove the workbed and drawer to accommodate thicker objects. The adjustable laser head is another great addition, allowing for precise focusing on materials of varying thicknesses.

Software and Usability

Due to its upgraded motherboard, the K40+ is compatible with many different types of laser engraving software. Whether you prefer LaserGRBL, Lightburn, or CorelDRAW, the K40+ can take it. This flexibility is super useful, especially for those transitioning from other design software or laser systems. 

In my experience, the K40+'s learning curve is relatively easy. The machine responds well to commands from my computer, and the positioning accuracy of ±0.02 mm ensures that your designs come out precisely as intended. The red dot pointer is invaluable for aligning your work and focusing the laser head, especially when working with irregularly shaped materials.

Performance and Applications

I’ve used the K40+ 40W CO2 laser machine for a wide range of projects. In my time with the machine, I’ve worked with wood, acrylic, leather, and cardboard to create simple keychains and decor, along with custom gifts to sell on my Etsy shop. 

My most recent project involved engraving and cutting 3mm thick Baltic birch wood. For this project, I set my Fill settings to 100% speed and 30% power and my Cut settings to 7% speed and 50% power. I ended up having to go over the Cut line twice, but the final result was a great piece of wood decor for my house. 

With the K40+ desktop laser engraver, creating simple yet spectacular designs on all types of material is a breeze. The 300 mm/s max engraving speed allows for quick project turnaround, while the ability to cut materials up to 1/8" thick opens up possibilities for creating small 3D objects and assemblies. While there are certainly faster CO2 laser machines out there, I think the K40+ does a fantastic job with the tools given. Personally, I don’t need all the bells and whistles (and frankly, the complexity) that come with larger and faster machines, so the K40+ is perfect for my small business needs!  

Safety Features

Safety is paramount in laser engraving, and the K40+ doesn't disappoint. The enclosed design with the large viewing window provides excellent protection from laser radiation and debris. The water cooling system is efficient, keeping the laser tube at optimal temperature even during extended use. Using a bucket for the cooling system works well, but if you’re in it for the long haul, I recommend eventually upgrading to a water chiller to keep things running smoothly. 

The built-in safety switches are a crucial feature, automatically cutting power to the laser if the lid is opened during operation. While these features are reassuring, I always use additional safety gear, like laser safety glasses and a proper ventilation system. Proper air filtration is one of the most important aspects of laser engraving, especially if you’re doing it inside. Crack open a door or window to vent the fumes outside, or use an air exhaust system if this isn’t possible. Ideally, you should be doing both to maintain optimal air conditions in your working area.

Maintenance and Longevity

After months of regular use, I can attest to the K40+'s durability. The machine requires minimal maintenance—the primary tasks are regular cleaning of the lens and mirrors, occasional alignment checks, and keeping the water in the cooling system clean.

The 40W CO2 laser tube has a respectable lifespan, typically lasting 1,000-2,000 hours with proper care. Replacing it is straightforward, and tubes are readily available on OMTech’s website.

Pros and Cons of the K40+

Pros:

• Excellent value for the power and features offered
• Wide software compatibility
• Compact size suitable for small workshops
• Capable of cutting and engraving a variety of materials
• Good safety features

Cons:

• Limited working area compared to larger machines
• May require some tweaks and upgrades for optimal performance
• Not suitable for metal cutting (engraving only with proper settings)

Conclusion

The K40+ laser engraver is a solid choice for those looking to enter the world of laser engraving or small businesses needing a reliable, compact machine. Its combination of power, precision, and versatility makes it suitable for a wide range of projects.

While it may not have all the bells and whistles of more expensive machines, such as a built-in camera or touchscreen interface, the K40+ more than makes up for it with its performance and value. The ability to use popular software like LightBurn is a significant advantage, allowing users to leverage powerful design tools without being locked into a proprietary system.

After extensive use, I can confidently say that the K40+ has earned its place in my workshop. It handles most tasks I throw at it with ease, and its compact size means it doesn't dominate my workspace. For anyone considering an entry to mid-level laser engraver, the K40+ should definitely be on your shortlist. It offers a great balance of features, performance, and affordability that's hard to beat in its class.