June 29, 2026
Description
The stock nozzle light on the Neptune 4 series is functional, but I wanted brighter and more even illumination around the nozzle.
This upgrade replaces the original single LED with two standard 5 mm LEDs positioned to illuminate the nozzle from both sides. The result is a brighter work area with fewer shadows, making it much easier to monitor first layers and print progress.
To keep the installation clean and compact, the holder features integrated resistor pockets and internal cable routing.
I originally contacted Elegoo support because I wanted to purchase the original nozzle LED as a spare part.
They offered the complete front fan assembly for US$19, or the original LED assembly for US$2. However, they initially recommended not shipping the LED assembly separately, as such a small package could easily get lost during international shipping. After asking, they were willing to sell it separately, but shipping to Germany alone was quoted at US$18.
That motivated me to design a simple replacement using inexpensive, standard 5 mm LEDs and commonly available electronic components. The result not only costs very little to build, but also provides brighter and more even illumination than the original single LED.
Dual 5 mm LED design
Even illumination from both sides
Integrated resistor holders
Internal cable routing
Compact and clean installation
Easy assembly
Designed specifically for the SilencedFrost SF 3×5015 Shroud
2 × 5 mm white LEDs
2 × 2 kΩ resistors
0.5 W (tested) resistors
2 × M3 × 10 mm socket head screws
Tested configuration
This upgrade was tested on an Elegoo Neptune 4 Plus using the printer's original 24 V LED supply.
The best results were achieved using 2 kΩ / 0.5 W resistors, providing excellent brightness while remaining cool during continuous operation.
My initial prototype used 1 kΩ / 0.25 W resistors. While they worked electrically, they became too hot for long-term use.
Supports are required.
For the best print quality, I recommend printing the model standing on its side rather than laying it flat. This produces cleaner LED openings, better cable channels and stronger layer orientation around the mounting holes.
Since the holder is installed close to the hotend, it should be printed using a material with good heat resistance.
Recommended materials
PETG
ABS
ASA
PC
PLA is not recommended.
The version shown in the photos was printed using self-made recycled PET (rPET) filament produced from recycled PET bottles.
Using rPET is optional—standard PETG works perfectly as well
Each LED uses its own 2 kΩ series resistor.
Connect both LED branches in parallel.
⚠ Important
On my Neptune 4 Plus, the connector polarity was reversed compared to the wire colors.
Always verify the polarity with a multimeter before connecting. Do not rely solely on the red and black wire colors.
The included wiring diagram reflects the polarity used on my Neptune 4 Plus. Always verify the polarity on your own printer before connecting the LEDs.
Designed for the SilencedFrost SF 3×5015 Shroud on:
Elegoo Neptune 4
Elegoo Neptune 4 Pro
Elegoo Neptune 4 Plus
Elegoo Neptune 4 Max
Special thanks to SilencedFrost for creating the excellent SF 3×5015 Shroud that inspired this upgrade.
License:
Creative Commons — Attribution — Noncommercial — NoDerivatives
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