Fixer's Journal
Fixing a Vacuum Hose with a Custom 3D-Printed Flexible Tube
A hands-on repair using FreeCAD, flexible TPU filament, and a simple helical design.
Why This Project? This project started with a broken vacuum cleaner attachment. A small internal hose that should've guided airflow from the brush to the main tube had deteriorated. Cracks and leaks meant poor suction. Instead of buying a new vacuum or scouring for a hard-to-find part, I decided to design and 3D print a replacement. The original hose had a metal spiral inside a soft sleeve—flexible, but hard to replicate. My approach? Recreate a similar shape with a flexible filament and simple geometry. It wouldn't be quite as soft, but it could restore function. And it did.
Results of troubleshooting
Step 1: Understanding the Shape
Measure
This isn't a traditional part. It's a flexible tube with a coil structure inside. That meant I needed to recreate a spring-like cross-section, extruded in a helix. Here's what I gathered before jumping into FreeCAD: - Cross-section of the coil: 3 mm - Tube diameter (outer): ~31 mm - Tube length: 180 mm (better to cut extra than fall short) I also learned through trial and error that overly thick walls would make the part too stiff and cause airflow blockages. The working version used a single perimeter thickness, about 0.4 mm, which is my nozzle diameter.
Useful Tools
Use this guide to find feature tools used in the following steps.
Step 2: Creating the Coil in FreeCAD
Sketching
1. I placed a 3 mm diameter circle on the sketch plane. 2. The coil needed to wrap around a central axis roughly 31 mm in diameter. 3. I used the Additive Helix feature and set: - Pitch: 10 mm (distance between spiral loops) - Height: 180 mm This gave me a spring-shaped core. It looked right, but wasn't airtight yet—we still needed an outer shell.
Step 3: Adding the Airtight Shell
Extruding Tube
To make the part functional as a vacuum tube: 1. I sketched a concentric tube shape around the helix. 2. The inner diameter: 30 mm The outer diameter: 31 mm This gives us a 0.5 mm wall, enough for a single printed layer. I extruded this shell along the same 180 mm height, creating a cylindrical sleeve around the helix. To trim the ends flat (to better mate with vacuum components), I used a subtractive sketch to cut off excess geometry.
Step 4: Preparing for Print in Bambu Studio
Material: TPU-based flexible filament
I exported the model as a STEP file and opened it in Bambu Studio. Print time: ~3 hours
Raft: Enabled to increase surface contact and prevent tipping. A note on speed: TPU prints best at lower speeds. I pre-calibrated settings including volumetric speed and temperature, which gave me clean walls and no stringing.
Assembly
Step 5: The Result
The part printed beautifully—no cleanup needed. The vertical filament lines lined up well, and the part was flexible enough to compress slightly while maintaining a seal. Functionally, it worked: no more air leaks, and the vacuum brush was fully restored. A key insight: printing just one perimeter (0.4 mm) was enough to maintain flexibility. Anything thicker resulted in kinks and airflow blockages.
The TPU tube bends without collapsing. Success!
Final Thoughts This wasn't a glamorous project, but it was a satisfying one. In about 20 minutes of modeling and a few hours of printing, I repaired something that otherwise might have ended up in a landfill. Sometimes, these small fixes are the most valuable. They extend the life of our tools and reduce waste. And they remind us that good design is often just a matter of looking a little closer, thinking a little longer, and willing to try. Thanks for following along. I hope this inspires your next repair.
The Ambient Form
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