OMTech K40+ Review: 40W vs 45W, LightBurn and Every Bundle

Compare the K40+ against a classic blue-box K40 and the differences line up with the usual upgrade order:

• Air assist: a built-in 45-degree nozzle that adjusts airflow with laser power. It clears smoke, protects the lens, reduces charring on wood and lowers fire risk.
• Bed: a honeycomb surface for flat stock, and a base that lifts out to make room for tall pieces or the rotary.
• Controller: LightBurn and LaserGRBL support instead of the M2 Nano's CorelLaser and LaserDRW.
• Tube: a 45W rating instead of the classic 40W.

OMTech gives the K40+ a 300mm/s top engraving speed and cutting 10mm acrylic and 8mm wood. Treat those thicknesses as best cases with clean optics, correct focus and slow speed, often over more than one pass. Everyday work on 3mm plywood and acrylic is where the machine is comfortable.

OMTech also backs the K40+ with two years of service and round-the-clock support, a real difference from anonymous K40 clones.

Many older OMTech K40+ 40W CO2 laser engraver reviews describe that earlier version. When you read them, check which tube the reviewer had. Most of what they say about the bed, the software and the body still applies; the cutting-speed numbers do not.

A 45W rating in a desktop body is a peak figure. Tube output falls with water temperature and age, and running at the top of the current range shortens the tube's life. Plan your settings so everyday cuts sit well below full power.

If you are weighing a used 40W K40+ against a new 45W, check three things before you pay:

• The tube's hours, or at least its age, and whether it still glows an even pink-purple.
• The state of the lens and mirrors, since smoked optics make any tube look weak.
• Which controller and software that particular machine runs.

A radiator cooler pumps water through a heat exchanger with fans; it has no refrigeration circuit. OMTech rates it at about 50W of heat removed for every 1 degree the water sits above room temperature. It cannot push the water below room temperature, so in a hot garage it keeps the water from climbing but will not make it cold.

• Tank: 9L, enclosed, with a sight window for the level.
• Flow: 2.6 gallons per minute through brass ports.
• Alarms: sensors, a display and indicator lights for flow and temperature faults.
• Shipping: the machine and chiller arrive as two packages.

Keep tap water and automotive antifreeze out of the loop; use distilled water or a laser coolant. OMTech's own coolant is ethylene-glycol based, non-conductive and prediluted, and it protects down to -31°F in a cold shop. Do not mix it with other coolants.

If your room regularly runs hot, a refrigerated chiller is the better tool. For most hobby rooms, the CW-3000 plus sensible job lengths is enough to keep a 45W tube happy.

LightBurn costs money after its trial period, which is why the OMTech K40+ LightBurn bundle includes the license. LaserGRBL is free but runs on Windows only. Both treat the K40+ as a GRBL-style machine, which is why OMTech lists them together.

K40 Whisperer, the free tool classic owners love, is written for the stock M2 Nano board. It is not the program to reach for on a K40+. The K40 software guide covers the full split between boards and programs.

The rotary bundle adds OMTech's rotary axis for 40W-45W lasers. It plugs into a dedicated port on a 4-wire cable, and you set it up in the software. Check its limits against your plans:

1. OMTech sizes it for round objects about 0.8 to 1.6 inches across, with a maximum of 2 inches between the drive rollers.
2. Remove the detachable base so the rotary and the object sit at focus height.
3. Run a test on scrap tube before you touch a finished piece, since round surfaces drift out of focus at the edges of a wide design.

Wider tumblers sit outside that roller range, so measure your favourite blanks before choosing the rotary bundle. For flat work, the base machine and a better exhaust fan are the smarter spend.

1. Open the tube bay and look along the tube for cracks, especially near the ends and the water nipples.
2. Connect the hoses, fill the loop and let the pump circulate until the tube shows no trapped air. Never fire the laser without flow.
3. Connect the machine to a properly earthed outlet and confirm the ground connection on the back.
4. Put on your 10,600nm glasses, then check the beam at each mirror with masking tape at low power.
5. Set focus on a scrap of 3mm plywood before judging cut quality.

Then fit the exhaust duct and run it to outdoors. The fumes from wood, leather and acrylic are unpleasant at best and harmful with some materials, and the fan is only as good as the duct behind it.

Once the K40+ runs, spend on the add-ons in order of risk, not excitement. Grounding and fumes get their own setup and safety walkthrough, the alignment guide covers mirrors and focus, and the Monport K40 comparison shows the closest alternative.

• Safety glasses for every person in the room.
• A fire extinguisher suited to electrical and wood fires.
• A spare lens, since it is the part most likely to crack.