SUMMIT PROTOWORKS • DIY PROJECT 2

DIY TPU Headphone Cover

Design and print a flexible replacement cover for a damaged headphone headband.

Concept → Model → Slice → Print → Evaluate

Before you begin: This is an intermediate design project. It assumes you already have basic familiarity with OpenSCAD and your chosen slicer. The project focuses on the design workflow rather than detailed software operation or printer setup.

1. Concept — Define the need

The original headphone headband covering is damaged. The goal is to design a flexible TPU cover that clips over the existing headband while remaining comfortable and secure.

Purpose
Cover and protect the damaged headphone headband.

Material
TPU 95A for flexibility and durability.

Fit
Measure the existing headband and design the cover to fit securely.

Shape
U-channel that wraps around the existing headband.

Mounting
Clip-on design without permanent modification to the headphones.

Print requirement
Designed so the part can be printed reliably in flexible filament.

2. Model — Build it in OpenSCAD

OpenSCAD is used because the cover can be built parametrically from the measured dimensions.

1. Define the parameters. Enter the measured headband dimensions and the required cover thickness.

2. Create the inside. Model the internal shape that fits over the existing headphone band.

3. Create the outside. Build the outer surface around the internal shape to form the U-channel.

4. Preview the model. Check the dimensions, wall thickness and overall U-channel geometry.

5. Render the model. Render the completed geometry and inspect it before export.

6. Export the STL. Save the model as an STL ready for slicing.

3. Slice — Prepare the print

Use the slicer of your choice and prepare the TPU model for printing.

1. Select the printer and TPU profile. Use a profile suitable for the TPU being printed.

2. Import the STL. Load the OpenSCAD model into the slicer.

3. Check orientation. Confirm the model is positioned correctly on the build plate.

4. Select the filament. Assign the TPU filament and appropriate material profile.

5. Slice. Generate the toolpath and inspect the layer preview.

6. Prepare the print. Send the job to the printer or export the appropriate printer-ready file.

4. Print — Make the object

Filament
eSUN TPU 95A

Profile
Bambu standard TPU settings

Wall loops
2

Infill
15% grid

Final thickness
2 mm

Print the cover and monitor the first layers to confirm good adhesion and correct extrusion of the flexible filament.

5. Evaluate — Check the result

The first version fitted the headphone band, but testing revealed a problem. When the cover was bent around the curved headband, the continuous side walls buckled.

Fit or dimensions
Return to CONCEPT

Geometry or buckling
Return to MODEL

Material or settings
Return to SLICE

Print quality
Return to PRINT

Evaluation result: The basic fit was successful, but the wall geometry needed to be redesigned to allow the TPU cover to bend without uncontrolled buckling.

5A. Model Revision — Correct the problem

The evaluation identified the continuous side walls as the problem. Return to the OpenSCAD model and modify the design while retaining the successful basic fit.

1. Add fingers. Replace the continuous side walls with flexible fingers that can follow the curve of the headphone band.

2. Add retaining clips. Add clips to help hold the cover securely around the headband.

3. Add retaining-clip holes. Create the matching holes required by the retaining clips.

4. Check the dimensions. Confirm the new features retain the required fit and clearances.

5. Render the corrected model. Inspect the revised geometry before export.

6. Export the revised STL. Return to Slice → Print → Evaluate.

Revised Design Dimensions

Overall length
235 mm

Inside size
35 mm wide × 13 mm high

Wall thickness
2 mm

Lower grip
8 mm

Finger gap
3.5 mm

Finger spacing
13 mm pitch

Outside size
39 mm wide × 17 mm high

Retaining holes
Ø4 mm

Retaining straps
11 × 35 × 3 mm

Retaining pins
Ø4 × 5 mm

Corrected OpenSCAD model with flexible fingers and retaining clips

The design process is iterative. Evaluation of a physical print can reveal problems that were not obvious in the original CAD model.

Finished TPU headphone cover installed on the headphones

Addendum — OpenSCAD Program Structure

The OpenSCAD program is organized into parameters and reusable modules.

1. Parameters

2. module inside

3. module outside

4. module fingers

5. module retainer_clips

6. module retainer_clip_holes

First model
Uses parameters, inside and outside modules.

Corrected model
Uses all modules, including fingers, retaining clips and retaining-clip holes.

Assembly calls at the end of the OpenSCAD program determine which modules are included in the generated model.