Laser cutters have come a long way from being sophisticated industrial equipments to workshop tools that fit on a regular-sized desk.
However, most professional desktop laser cutters cost a few thousand dollars, which is a lot of money for a hobbyist looking to explore laser cutting.
The introduction of K40 laser cutters made quality laser cutting accessible for under $1000.
This article provides a complete guide on K40 laser cutters, offers insights about the possible upgrades, and discusses some of the best K40 laser cutters available in the market.
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What is a K40 laser cutter?
K40 laser cutters are budget-friendly CO2 laser cutters with a maximum power output of around 40W. These laser cutters are priced at around the $500 mark and usually have several upgrades and customization options to enhance their capabilities.
K40 is a generic name for affordable laser cutters with around 40W laser power.
These laser cutters were introduced by Chinese manufacturers to offer affordable CO2 laser cutters at around $500.
Most manufacturers now ship these units from various other countries, including the USA, and also provide US-based technical support.
This makes K40 laser cutters ideal for beginners and hobbyists who want to explore CO2 laser cutting on a budget.
However, the budget-friendly price comes with limited features, which cannot be compared to other expensive laser cutters like Glowforge and FSL Muse.
These lasers are ideal for personal use, but if you plan to run a small-scale business venture, these might not be ideal.
For example, a K40 laser can perform clean engravings on thick/dense paper with a cutting speed of around 100 mm/sec.
Therefore, using a K40 laser to print a typical wedding invitation at this speed will take around 10 minutes to engrave one unit, and around 33 hours to print 200 invitations.
Furthermore, these laser cutters generally provide a small work area that is suitable for working with objects like leather wallets, keychains, invitations, tumblers, etc.
Basic Features of a K40 Laser Cutter
Although there are various K40 laser cutters offered by different manufacturers, these machines have similar features with almost identical designs.
K40 lasers feature a box design made of folded sheet metal with a laser-safe acrylic window on top, which allows you to monitor the laser cutting process.
The front panel offers some basic controls such as an on/off switch, laser switch, test switch, current regulator, and current indicator, while some units also include an emergency stop button.
At the back of a K40 laser cutter, you will find some basic connection ports such as power input, ground wire connection, cooling water inlet/outlet, exhaust outlet, and power output ports to operate the exhaust fan and cooling pump.
These lasers are generally available in two colors: blue and red.
Although there is no significant difference between the two, some manufacturers usually color code their units, with red units having a digital ammeter and blue ones housing an analog ammeter.
These laser cutters generally have a footprint of around 32" x 20" x 10" and offer a work area of around 8" x 12".
The closed construction of K40 laser cutters makes them safe to use even for beginners.
Table representing material processing capability of K40 laser cutters
K40 laser cutters, as the name suggests, house a 40W CO2 laser capable of cutting and engraving various non-metals.
The wavelength of a CO2 laser is not suitable for metals and, therefore, cannot be used for applications involving metal cutting or engraving.
However, it can be used for engraving anodized aluminum and laser etching metals by applying laser marking ink on the surface to be etched.
It must be noted that using a laser at its peak power damages the laser tube and significantly reduces its life.
Therefore, a K40 laser with a 40W CO2 laser tube will offer a maximum operational laser power of around 30W - 35W.
K40 lasers are capable of engraving almost every non-metal material, but their low laser power limits them from being able to cut certain tough materials like ceramic, stone, and glass.
CO2 lasers are basically infrared radiations that are invisible to human eyes, and therefore a stray laser beam can go unnoticed and enter the eyes of the operator, causing permanent damage.
Cooling and Ventilation
CO2 laser cutters require a cooling system to prevent the laser tube from overheating.
Most K40 laser cutters ship with a submersible coolant pump included in the kit, which is used to supply the coolant (generally water) to the tube by immersing the pump in a container filled with coolant (water).
Regular tap water contains minerals and salts that conduct electricity, which can be dangerous when operating a high-voltage laser system.
Therefore, it is recommended to use distilled water for cooling the laser tube safely, reducing the risk of electrical hazards.
Furthermore, laser cutting uses a high-energy laser beam to burn and vaporize the material, producing heavy smoke.
This smoke can stain the workpiece, and the fumes produced by certain materials like vinyl can be extremely dangerous if inhaled by the operator.
A good quality ventilation system is required to effectively dispose of the smoke away from the workpiece and the operator.
Generally, K40 laser cutters include an exhaust fan and a duct to dispose of the smoke away from the work area.
However, the exhaust fan included in the kit is a low-powered fan suitable for applications that produce light to moderate amounts of smoke.
Moreover, if your requirement involves working with applications that produce toxic fumes or heavy smoke, it is strongly advised to upgrade the ventilation system by installing a powerful exhaust fan.
Controller and Electronics
Depending upon the manufacturer, K40 laser cutters come with different controller setups.
When selecting a K40 laser cutter, it is important to look for key features and support provided by their controller.
While some controllers offer 5-axis support, others do not provide support even for a 3rd axis, also known as the rotary axis.
The rotary axis is one of the most common upgrades for K40 laser cutters, which enables you to engrave on cylindrical objects.
Furthermore, a 32-bit controller outperforms 16-bit and 8-bit controllers by providing faster processing speed and better cutting ability around the corners.
Almost all K40 lasers provide a USB port to connect the laser cutter with a computer.
They also provide a red dot pointer that helps in positioning the laser before executing the cut.
It also improves safety as the red dot provides a reference for the point of contact of the invisible CO2 laser.
There are various laser cutter/engraver software that can be used to create the design (CAD), generate G-codes (CAM), and interact with the laser cutter.
However, the software supported by a K40 laser cutter depends on its controller.
Generally, K40 laser cutters provide support for LaserDraw and CorelLaser software, but K40 Whisperer is a free CAM software that provides a feature-rich alternative with better functionality and a user-friendly interface.
It takes SVG and DXF files as input and converts them into G-codes to execute the desired process.
Despite being cheap, a K40 laser cutter kit includes all the basic accessories required to get started with laser cutting.
A typical K40 laser cutter kit includes the main laser unit (metal box with controls and laser tube), a power supply unit, exhaust fan, exhaust duct, user manual, USB cable, and a flash drive containing all the related software and documentation.
Furthermore, you can also include an optional rotary axis in your K40 laser cutter kit to engrave cylindrical objects like tumblers and wine glasses.
K40 laser cutters generally ship as semi-assembled kits that require a bit of tuning before getting started.
Tuning the laser includes leveling the laser tube and adjusting the mirrors, which can be quite tedious and requires adequate knowledge about the working of a CO2 laser cutting system.
Leveling the laser tube ensures a uniform flow of water (cooling liquid) to prevent the tube from overheating.
This also improves the performance of the laser by maintaining the temperature under the normal operating temperature range.
Furthermore, a CO2 laser system consists of a series of mirrors that guide the laser beam towards the focusing lens.
Improper alignment of these mirrors will result in loss of laser energy and inefficient laser focus.
Therefore, it is recommended to perfectly align the mirrors to attain the best results with a tight laser spot.
However, aligning the mirrors for an invisible infrared laser beam can be challenging.
A simple trick to ensure perfect alignment is to cover the mirror with a masking tape and fire the laser for a short duration by pressing the 'laser test' button.
After firing the laser, check the position of the mark made by the laser on the masking tape.
If the position of the mark coincides with the center of the mirror, it is perfectly aligned.
Repeat the process for all the mirrors in sequential order, starting from the very first mirror of the beam delivery system.
Although K40 lasers are mostly manufactured in China, many manufacturers provide US-based customer support.
However, you cannot expect the same customer support that you get from expensive American-made lasers.
Therefore, these machines are not recommended for professional applications where you need quick solutions.
Nevertheless, K40 laser cutters are ideal for hobbyists and DIY enthusiasts who like to tinker with their machines.
Upgrades to Enhance the Functionality of a K40 Laser Cutter
The ability to upgrade the functionality of a K40 laser cutter makes them one of the most popular laser cutters among hobbyists and DIY enthusiasts.
There are various upgrades available on the market, which can be installed to explore the full potential of your K40 laser cutter.
Upgrading the focusing lens is an easy way to make the laser cut deeper with higher precision.
Most K40 laser cutters include a basic 2" focusing lens that produces satisfactory results for engraving and cutting.
Changing the focusing lens to suit your application will enhance the functionality of the laser cutter.
Generally, the smaller the focal length of a lens, the smaller its spot size and depth of field.
Small lenses are ideal for engraving intricate patterns with high precision.
However, as the depth of field of a laser increases, its ability to cut deeper also increases.
Therefore, for cutting thick objects, it is recommended to upgrade your K40 laser cutter with a larger focusing lens.
Air assist is the use of compressed air to blow the molten material out of the kerf while protecting the focusing lens from smoke and molten debris.
It enhances the ability of a laser to cut through the material and prolongs the life of the laser equipment by preventing it from overheating.
Upgrading your K40 laser cutter with an air assist system requires an air pump and an air assist compatible laser head.
The exhaust fan provided with most K40 laser cutters is a low-power fan, which is suitable for applications that produce a small amount of smoke during laser processing.
Laser engraving flammable materials such as wood, paper, fabrics, leather, etc., can produce heavy smoke that requires a powerful exhaust system to dispose of efficiently.
Upgrading your K40 laser cutter with a powerful exhaust system will improve the quality of the cut and prevent harmful fumes from reaching the operator.
Generally, it is recommended to connect the exhaust fan at the end of the duct.
This creates a negative pressure inside the duct, pulling the smoke and debris towards the exhaust instead of pushing them out and damaging the duct.
Although using ice-cold distilled water is an effective way of cooling the laser tube, using a chiller enhances the performance of a laser cutter and prolongs its life.
However, it is an expensive upgrade that can sometimes cost more than a K40 laser cutter.
Therefore, it is generally recommended to upgrade to a chiller system only if your application involves operating the laser at maximum power output for long durations.
Upgrading the laser tube enhances the performance and ability of a K40 laser cutter.
Replacing the 40W (practically 30W) laser tube with a 50W tube will enable to explore the true potential of a K40 laser cutter by providing an operational laser power of around 40W.
However, it is one of the most expensive and difficult upgrades that requires good knowledge about the laser system.
Furthermore, operating the higher-powered laser tube will also require an upgraded power adapter and controller.
It must be noted that CO2 laser tubes operate at high voltage electricity, and therefore it can be extremely dangerous to upgrade the laser tube without proper guidance.
Best K40 Laser Cutters in 2022
OM Tech DF0812-40BG is a desktop K40 laser cutter that has a footprint of around 32” x 20” x 18” and offers a work area of 12" x 8".
It comes with a vented level-board installed on the work table that facilitates easy clearance of smoke away from the cutting area.
OM Tech DF0812-40BG offers a standard Z-height of around 0.5", which can be increased to 2.5" by removing the vented level board.
However, removing the vented level board reduces the work area to around 8" x 5".
OM Tech offers this laser cutter in two color combinations: red-white and blue-gray.
It houses a 40W CO2 laser that offers maximum cutting and engraving speeds of around 15.8 ips and 19.7 ips, respectively.
The front panel of OM Tech DF0812-40BG consists of manual control buttons, an emergency stop button, and a digital display that provides power and temperature information.
OM Tech DF0812-40BG comes with an exhaust fan and a duct that facilitates disposing of the smoke away from the working area.
It also includes a coolant pump that helps to circulate the cooling liquid to the laser tube.
OM Tech DF0812-40BG is compatible with LaserDRW, CorelLaser, and CorelDraw software but does not support LightBurn software.
Furthermore, the standard controller of OM Tech DF0812-40BG does not provide support for features such as a rotary axis and autofocus.
However, OM Tech provides a controller upgrade that is compatible with LightBurn software, and provides support for rotary axis and auto focus feature.
OM Tech provides a 2-year parts warranty on all 40W laser cutters with a 6-month warranty on laser tubes and power supply.
All these features, combined with their responsive US-based customer support, make OM Tech DF0812-40BG one of the most reliable K40 laser cutters in the market.
40W CO2 laser with red dot pointer
Compatible upgrades and 2-years part warranty
Mophorn 40W laser engraver has a footprint of around 20" x 31.5" x 11.8", which offers a work area of 12" x 8".
It is an affordable K40 laser cutter that houses a 40W CO2 laser and offers high positional accuracy of around 0.004".
This makes it ideal for cutting and engraving intricate patterns on various materials such as paper, cardboard, wood, cork, leather, etc.
It offers a high engraving speed of around 11.8 ips with a maximum engraving resolution of 2500 dpi.
Mophorn 40W laser engraver comes with a pre-installed exhaust fan that facilitates in easy disposal of smoke, and the long duct pipe enhances its portability.
It also includes a water pump in the kit that prevents the laser equipment from overheating even during long operational hours.
The front panel of Mophorn consists of basic laser controls, an emergency stop button, and two LCDs for power and temperature readings.
Mophorn Laser engraver is compatible with CorelDraw software that runs on Windows platforms and recognizes file formats such as JPG, BMP, AI, and PLT.
High part accuracy (~0.004 inches) and engraving speed (~11.8 ips)
with exhaust system and cooling pump
Zikebtuy laser engraver houses a 40W CO2 laser tube that can cut and engrave various non-metals.
It has a footprint of around 47" x 34" x 27.6" and provides a work area of 12" x 8".
The front panel of this engraver consists of an emergency stop button, an on/off switch, control buttons, and an LED to display laser power.
Zikebtuy laser engraver kit includes a flash drive containing LaserDRW and CorelLaser software compatible with Windows platforms only.
However, it does not support LightBurn software but can be used with K40 Whisperer software.
Overall, it is an affordable laser cutter that offers a 2-year parts warranty on the laser engraver and a 6-month warranty on the laser tube and power supply.
With exhaust system and CorelLaser software
2-year parts warranty & 6-months warranty on laser tube and power supply
K40 laser cutters are excellent beginner-level machines ideal for hobbyists and DIY enthusiasts.
These lasers can be easily upgraded as you become more familiar with them.
However, their low power and small work area are not suitable for professional applications.
Upgrading a K40 laser cutter requires proper knowledge about the working and compatibility of the system and, therefore, should not be performed without proper guidance.
Frequently Asked Questions (FAQ)
Can a K40 laser engrave metal?
No, a K40 laser cannot engrave metal. However, it can be used to engrave anodized aluminum and laserable brass as these metals have a non-metallic coating over the bare metal surface. The CO2 laser removes the non-metallic coating, revealing the shiny metal underneath to produce a bright engraving pattern.
Is K40 Whisperer software compatible with every K40 laser cutter?
Yes, K40 Whisperer software is compatible with almost every K40 laser cutter. K40 Whisperer enhances the functionality of the machine by providing a user-friendly interface and extending its support to Linux and Mac platforms. Generally, all laser cutters that are compatible with LaserDRW software can be used with K40 Whisperer software.
What is depth of field in laser focus?
The maximum deviation from the focal length for which the laser can engrave and cut materials effectively. When a laser passes through a focusing lens, it converges along a conical path into a tight spot and then diverges again following a similar conical path. However, the laser is effective throughout a very short distance on either side of the point of convergence, this is called the depth of field of laser focus. Generally, lenses with longer focal lengths have a greater depth of field.