GlowBar – Full-Width LED Status Bar for Prusa CORE One/+/G2, CORE One L/+, XL/+ & MK4/S

Overview

GlowBar is an original full-width LED Status Bar that turns the printer’s Status LEDs into a clean, continuous band of color.

GlowBar was developed after trying existing Status Bar models and remixes that did not meet my expectations for fit, transparent print quality, or overall geometry. I built GlowBar around a close xLCD cover contour and broad, uninterrupted optical surfaces for a cleaner, more uniform illuminated appearance.

The geometry is designed for support-free printing and minimizes visible layer lines that can interfere with the illuminated appearance.

The included 3MF contains an optimized transparent PETG print profile for bright, uniform illumination.

GlowBar installs as a press fit in the original Status LED slot of the xLCD cover.

Bonus — Status LED Color Demo Files

Includes 13-color Rainbow and 7-color Pure LED cycles—ideal for previewing colors, taking photos, and comparing GlowBar’s illuminated appearance. See instructions at the end.

Benefits

• Full-width GlowBar design

• Integrated silhouette that follows the original cover contour

• Press-fit installation — no additional hardware

• Optimized transparent PETG print profile included

Compatibility

GlowBar installs directly into the Status LED slot of the stock xLCD cover supplied with the printer. Its fit is based on the shared injection-molded xLCD cover design used across the compatible models.

• Tested and confirmed:

  • CORE One/+/G2

  • CORE One L/+

  • XL/+

  • MK4S (rev A cover)
    

• Expected to fit (not yet physically tested):

  • Legacy Rev B xLCD configurations, including older MK4/MK3.9-based printers, have not yet been tested.

  • Let me know in the comments if you try one.

Included Models

• GlowBar-Full-Width-Status-Bar.stl – Full-width GlowBar STL for custom slicing

• GlowBar-Full-Width-Status-Bar.3mf – Includes an optimized transparent PETG print profile for bright, uniform illumination

Installation

1. Align the GlowBar with the Status LED slot of the xLCD Cover.

2. Insert the upper edge of the GlowBar into the slot.

3. Push the GlowBar upward against the top of the slot while pressing evenly along its full length.

4. Once the upper edge is fully seated, the curved inner shape of the slot guides the GlowBar into its final position.

The bar is retained by friction. No additional hardware, adhesive, or printer modifications are required.

Transparent PETG Printing

The included print profile builds upon the principles described in Prusa Research’s article 3D-Printed Lens and Other Transparent Objects.

Since the article was published, printers, slicers, and filament profiles have evolved. The profile was therefore updated and tested with Transparent PETG on a Prusa CORE One/+.

The settings prioritize optical clarity, uniform illumination, and a clean surface finish rather than shorter print time. Further speed optimization may be possible, but was not the objective of this profile.

Print Settings

The included 3MF already contains the optimized transparent PETG print profile. If you prefer to print the STL using your own profile, the key settings are listed below.

Build Plate and Filament Preparation

A smooth sheet generally produces a clearer finish, while textured or powder-coated sheets create a more matte, light-diffusing surface. This has little impact on GlowBar because the textured surface is limited to the bottom face.

Use thoroughly dried transparent PETG. Moisture can introduce bubbles and extrusion irregularities that make the finished part appear cloudier and reduce optical clarity. 

Print Settings Overview — Detailed Settings Below

• Nozzle: 0.4 mm

• Material: Transparent PETG (other transparent filaments not tested)

• Layer height: 0.10 mm

• First layer height: 0.20 mm

• Print speed: 20 mm/s

• Perimeters: 1

• Top solid layers: 0

• Bottom solid layers: 0

• Infill: 100%, *** Fill pattern: Aligned Rectilinear, Fill angle: 90° ***

• Supports: Not required

• Brim: Not required

Print Settings → Layers and Perimeters

• Layer height: 0.10 mm

• First layer height: 0.20 mm

• Perimeters: 1

• Top solid layers: 0

• Bottom solid layers: 0

Using a single perimeter without top or bottom solid layers allows the aligned infill to form almost the entire illuminated body of the part, reducing internal interfaces that scatter light.

Print Settings → Infill

• Infill density: 100%

• Infill pattern: Aligned Rectilinear

• Infill angle: 90°

The orientation of the extrusion lines has a significant influence on the illuminated appearance.

Print the model lengthwise from left to right on the build plate. With the infill angle set to 90°, the extrusion lines run from front to back and will be perpendicular to the xLCD Cover once installed. This helps produce more uniform illumination across GlowBar’s full width.

Print Settings → Advanced

• Default extrusion width: 0.55 mm

• First layer extrusion width: 0.60 mm

• Perimeter extrusion width: 0.55 mm

• External perimeter extrusion width: 0.55 mm

• Infill extrusion width: 0.55 mm

• Infill/perimeter overlap: 5%

• Automatic extrusion width calculation: Disabled

Wider extrusion paths reduce the number of adjacent lines required to fill a part. This can reduce internal boundaries and microscopic gaps that scatter light.

However, with GlowBar’s current geometry, testing did not show a significant visual improvement over the default 0.45 mm extrusion width. The 0.55 mm setting remains a general recommendation for transparent printing and can be more beneficial with other part geometries.

Print Settings → Speed

• Perimeters: 20 mm/s

• Short perimeters: 20 mm/s

• External perimeters: 20 mm/s

• Infill: 20 mm/s

• Solid infill: 20 mm/s

• Bridges: 20 mm/s

• Gap fill: 20 mm/s

• First layer: 20 mm/s

Slow and consistent printing promotes more uniform extrusion and gives adjacent paths more time to merge. Consistent print speed is more important than absolute print speed.

Filament Settings

The included profile was developed and tested with OVERTURE PETG Transparent, but the same principles can be applied to other transparent PETG filaments.

Temperature and extrusion multiplier may require minor adjustment depending on the filament and printer calibration.

Filament Settings → Filament

• Tested filament: OVERTURE PETG Transparent

• Nozzle temperature, first layer: 245 °C

• Nozzle temperature, other layers: 245 °C

• Bed temperature, first layer: 85 °C

• Bed temperature, other layers: 85 °C

• Extrusion multiplier: 1.05

Following the principle described in Prusa Research’s article, the extrusion multiplier was increased to reduce microscopic voids between adjacent extrusion paths. The included profile uses 1.05.

A nozzle temperature of 245 °C, combined with slow printing and reduced cooling, promotes consistent fusion while remaining within OVERTURE’s recommended range. The 85 °C bed temperature was selected for reliable first-layer adhesion.

Filament Settings → Cooling

• Automatic cooling: Enabled

• Minimum fan speed: 10%

• Maximum fan speed: 20%

• Bridge fan speed: 60%

• Disable fan for the first: 3 layers

• Dynamic fan speeds: Enabled

• Enable fan below: 20 s

• Slow down below: 8 s

• Minimum print speed: 15 mm/s

Reduced cooling allows adjacent extrusion paths to fuse more completely, helping produce a brighter and more uniform illuminated appearance.

Feedback

If you print this model, I'd love to see your results. Feel free to post a Make or share your own transparent PETG settings and improvements.

Bonus: Status LED Color Demo

Want to preview how the Status LEDs look in different colors?

Prusa Status LEDs can be controlled with the M150 G-code command. The two included demonstration files cycle through a selection of Status LED colors three times—useful for photography or for comparing the illuminated appearance.

Because Printables does not accept uploaded G-code files containing the M150 command, the demonstrations are provided as text files.

To use a demonstration file:

• Download Status-LED-XXX-Color.txt

• Optionally open it in any text editor to review or modify the commands

• Rename it to Status-LED-XXX-Color.gcode

• Copy it to a USB drive and run it like any other G-code file, or upload it through Prusa Connect

G-code files are plain-text files, so their contents can be reviewed and edited with any text editor.

The files contain no heating, homing, movement, or extrusion commands. They only change the Status LED colors, then turn them off when the sequence finishes.