The true cost of a Monport K40 CO2 Laser


The Monport K40 series of CO2 laser engravers have slowly evolved into a more flexible tool using controller hardware that now supports Lightburn software.  We also have better control of the power output of the laser.

A CO2 laser is different from an LED laser in several ways.  First, the laser beam is a different frequency of light than the Blue LED lasers allowing the CO2 laser to engrave and cut through materials that the LED laser cannot.  The CO2 laser uses a high-voltage power supply to excite the CO2 gas in the laser tube; the laser also needs water cooling.  


One of the significant advantages of the K40 laser is the complete enclosure to protect the user from the high voltage power supply and Laser emissions.  While the enclosure also limits the engraving area of the laser to about 8 in by 12 inches, the safety features are very welcome.  This is a bit like the limited space on most 3D printers, and we need to understand it.

Out of the box, the K40 is a fully functional device that still needs a little help.  First is water cooling.   Most suppliers ship a small water pump; you must supply a bucket and water for the system.  The CO2 laser tube does not want to be too hot or cold.  I have grave doubts about the long-term viability of using this system for cooling.  This can get you started but will be fussy in the long term having to chill the water down during operation.    This is where I messed up the first time by not studying the internet!  There is a chiller out there that does not do the job.  You will find a model number similar to xx-3000.  This unit does not contain a compressor to chill the water; it is a total waste of about $200.  The 5000 series of chillers have compressors to refrigerate the water.  While these devices are around $550, they eliminate problems of improper water flow and temperature regulation.


A final warning about using this type of laser in an unconditioned space: the CO2 laser tube has a water jacket.  Frozen water will break the laser tube.  Water that is too hot will drastically reduce the life of the tube.

The bed of the K40 laser is a fixed distance from the laser.  There is a removable center section; to place items lower, but you need to build your own structure.    This design is an abomination.  I do not know why it was made this way.  You cannot adjust for material thickness; when cutting, the laser will flash back up, burning the back of the work: a messy business.  There are a lot of videos and ideas on YouTube with methods that work.  I have tried a couple with less-than-stellar results.  I developed my own system that still does not work well.  I have ordered the Light Objects power bed kit, and it also has some issues that need to be addressed.  As received, it does not fit in the Monoport K40 because of the design of the limit switches.  All of the screws were loose and more.  Another project!

Engraving things like wood on the K40 produces SMOKE!  Other materials give off toxic fumes. The fan in the rear of the laser is noisy and less than adequate.  I have removed it and the internal shroud to improve airflow for my shop air extraction system, which has a much larger radial fan.  The internal shroud limits airflow and needs to be appropriately designed to extract air.   The cabinet must most likely be changed to allow air into the enclosure.

An air assist is a must to prevent flare-ups and excess smoke from damaging your work.  I am experimenting with two systems.  First, is a slip-on 3d-printed nozzle that seemed a good start but was not; the lens was covered in smoke particles.  Fitting some aquarium hose through the drag chain worked well.  The stiff stuff some folks use drags on the stepper motors, which I dislike.  I am using that hose for routing outside the case as it does not kink.  I have been working with an ATEZR adjustable air pump and am very happy with it for both lasers.  

I have purchased a laser head that has a built-in air nozzle.  I will use a better mirror and lens in that nozzle here shortly.  I will do this in phases, as I want to make sure the aim of the first two mirrors is precise.

While the entry-level cost of the K40 is pretty enticing, we need to assemble a complete package to fit it out properly.  NOTE that the prices shift around a bit.

Here is my initial list:

  • Monport K40 (Lightburn edition) $550
  • Light Object Q600 Chiller $435
  • Light Object Z-table $295
  • ATEZR KA Air Assist $129
  • Laser assist mount $16
  • Laser head with Air Assist $27
  • Upgrade lens and mirrors for $60

Total $1512

Labor TBD

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