About the Mini marimba
A small marimba with 13 printed bars, tuned by length to C major from G4 to E6, over printed resonance pipes. The bars are tuned for one particular PLA (Prusament Vanilla White). A different colour or material may put them out of tune, and the designer's Python script on GitHub helps you retune. Print the bars at 50% infill and 0.1 mm layers. Importantly, let them cool for about 24 hours before playing, or they won't be in tune.
The resonance pipes print at 15–20% infill and 0.2 mm, with the longest split in two and superglued. The bar holders and the pipe holder are also split for gluing, and the outer frames are turned to fit the bed. Everything else slots together without glue. The bars are strung onto the holders with fishing line, tensioned by a small spring, and floats slide onto the mallet arms. The designer later noted using 0.8 mm top and bottom layers with 2 shells, without testing how that affects the sound.
In the video a robot plays it, built with the GitHub code.
What you'll need
Printed parts
- 13 bars
- Resonance pipes (longest in two parts)
- Bar holders, resonance pipe holder and outer frames
- Mallets
Bought parts
- Fishing line
- 2 floats
- A small spring
- Superglue
Tools
- A tuner app (to check the bars)
Build overview
- Print the bars. Prusament PLA Vanilla White, 50% infill, 0.1 mm layers, then let them cool for 24 h.
- Print the frame. Pipes at 15–20% infill and 0.2 mm, plus the holders and frames, then glue the split parts.
- Assemble the frame. Fit the bar holders into the outer frames, add the pipe holder and slide in the pipes, with no glue.
- String the bars. Thread the bars onto the holders with fishing line and tension it with the spring.
- Finish. Slide the floats onto the mallet arms.
Print settings
- Bars: 50% infill, 0.1 mm
- Pipes: 15–20% infill, 0.2 mm
- Top/bottom: 0.8 mm, 2 shells (designer's later note)
- Supports/rafts: None
Video
Play video: A robot plays the 3D-printed mini marimba (loads YouTube)
Nothing loads from YouTube until you press play. Video thumbnails are © their creators.
Photos
All photos: Equals Engineering, from the design page on Printables, licensed CC BY-NC. We resized them and converted them to WebP, and used the first frame of animated images.