16. PLH3D-6W LASER HEAD
This sub-assembly is a high power engraving laser head with thermal protection and professional high-speed driver. Its design ensures that the head doesn’t require any additional cooling. Fan design makes it work as a fully customized air nozzle protecting the lens from dirt and cooling the laser head. PLHD 3D 6W driver ensures proper work of the laser head and protects laser diode from overheating.
At 45 degrees the laser head switches off. Turning the collimating lens allows changing the beam focus distance. Airflow from the fan keeps the lens clean during operation. You can use two types of lens with our PLH3D laser heads. G2 lenses are popular because of the efficiency but it is not the most important parameter. While engraving, power density is more important - unfortunately G2 lenses are not providing small beam spot (while focused). Three element lens which is making bigger optical power loss allows obtaining a smaller beam spot which helps to obtain bigger power density.
The choice is up to customer's requirements since in some situation it is better to use G2 lens and sometimes three-element lens. The laser head allows to cut or engrave materials such as rubber, wood, paper, leather, plastic, cardstock and many other. Thanks to full analog modulation it is possible to engrave in shades of grey or change the output power during turns. The same effect can be achieved by using the PWM signal which is fully compatible with PLH3D driver. High-speed modulation (up to 100 kHz) allows using of high movement speed during engraving even complicated patterns.
The module is using brand new NUBM44 450 nm diode (capable of 6 W) which is strongest available on market blue laser diode. Recommended power supply unit is 12 V with current capacity at least 2.5 A.
The lifetime of the laser diode given by the manufacturer is 10000 h. It is also possible to buy a version with an additional aluminum holder which allows mounting the engraving laser head on the moving part of the machine.
Main advantages of the PLH3D-6W:
- Highest available power in a single diode
- Easy connection to all 3D printers and CNC machines producers.
- No need for additional cooling.
- Simple installation to all 3D printers and CNC routers
- A driver attached to the laser head.
Dimensions of laser head (LxWxH mm)
40 x 55 x 69
Modulation voltage range (V)
0 – 5 (0 – 24 for TTL input)
TTL or analog
Input voltage (V)
Mounting holes raster (mm)
24 x 15
Focus distance (mm)
20 - 120
Diode power (W)
Maximum power consumption (W)
Beam spot width (mm)
Beam spot height (mm)
0.2-0.4 dep.on focus
Example beam spot size at 80 mm distance
0.1 x 0.4 mm
Internal part no
Connection of the laser head
Connecting PLH3D 6W laser head is very simple and is using 5-core cable. To each device, 5 ways terminal strip is included.
Remember to use both GND cables
- white - Analog input 0-5 V laser power is proportional to the voltage given on this input
- grey – TTL in 0-24 V all voltage given over 3 V on this input gives maximum power and all voltage below 2.5 V gives no power
- yellow – Analog/TTL GND
- green – GND
- brown – Vcc 12 V (minimal current provided: 2.5 A)
Brown and green wires should be connected to the proper power supply unit which also can be bought at our website or together with the laser head.
Both ANG in and TTL in inputs can be used as PWM inputs. ANG in and TTL in should be used separately.
The additional single-lens collimator is attached. Premounted three-element lens collimator is 30% less efficient but it has 2 times smaller spot. You can check which one works best for you.
PLH3D laser head has aluminum cover for a driver. It protects laser driver from dust and metal chips which may be produced during milling.
Setting the focal length/distance
Setting the focus distance should be firstly done by turning the lens and then, after making the lens not move, by using your Z-axis in the CNC machine. Focus depends on the type of lens used and their distance from the laser diode. Remember, do not change the position of the lens while the laser is operating. Switch the laser every 0.5 turns of the lens in order to check the beam spot position.
Be careful not to unscrew the lens accidentally – the lens can fall down and get dirty/destroyed. For three-element lens, focus length should be in the range between 120 and 40 mm. For a single element lens, it should be in the range between 100 and 20 mm. Nevertheless, accurate focus distance should be set according to the test made with your material. The front cover should be put back in its place after setting the focus.
• Remember that it is not a toy. Laser radiation is dangerous even when scattered or reflected from any surface.
• Always use proper protection laser filter on your CNC machine dedicated to 430 - 480 nm in order to avoid reflected radiation.
• Never point laser head at people or animals.
• Do not touch the beam, it may cause burns.
• Do not stare at the beam or the beam spot while the material is being cut.
Recommendations and requirements
Modulation TTL input can be used as TTL/PWM input with its logic levels of 0 V and >3 V (24 V max). Analog input can be used as both: analog modulation or TTL/PWM (but 5 V max). Analog modulation means that by using 2.5 V on ANG input you get 50% output power, analogically by using 4 V you obtain 80% output power, etc.
Cleaning the optics is important since dirty optics reflect some % of power back to the diode what may be damage it irreparably. Airflow is very important during the engraving process since it is blowing out dark smoke which can cause an optical obstacle for a laser beam.
This module has a thermal protection system which protects laser diode from overheating. Both analog and TTL inputs are protected by Zener diodes on occasion there appear voltages higher than acceptable. Despite everything, those inputs should not be used with higher voltages. The power supply input is protected against reverse and too high input voltage by a transil diode. The transil diode will not protect the laser head in every case, please be careful when connecting the power supply. The output of the driver is protected by Schottky diode which doesn't allow the reverse voltage to appear.
Dimensions of the aluminum mount
Dimensions of the fi43 nozzle
PLH3D 6W XF with fi43 nozzle
PLH3D 6W XF with aluminum holder
Additional components for PLH3D 6W
Parameters of cutting
Note, that these speeds and parameters are effects of tests and can be different for some materials, cooling systems as well setting of the focus distance.
Balsa 5 mm: 30 mm/s; 6 W; 5 passes
Fiber-reinforced foil (green): 0.1 mm: 50 mm/s; 6 W; 1 pass
Rubber 0.5 mm: 15 mm/s; 6 W; 3 x 0.25 passes
Cardboard (0.5 mm): 8 mm/s; 1 passes.
3-layer cardboard (1.4 mm): 20 mm/s, 3 (0.5 mm step) passes.
5-layer cardboard (5 mm): 10 mm/s; 4 (1.25mm step) passes.
Polyfoam (15 mm): 8 mm/s; 2 (10 mm step) passes.
Polyfoam (24 mm): 5 mm/s; 2 (10 mm step) passes.
Leather (1.7 mm): 5 mm/s; 2 (1 mm) passes.
Jeans 0.5 mm: 8 mm/s; 6 W; 1 pass
Green Plexiglass 3 mm: 2 mm/s; 2 W; 6 x 0.75 passes.
Red Plexiglass 3 mm: 2 mm/s; 4 x 0.75 passes.