The O'Cello is a 3D-printable cello developed by Conor O'Kane, which is free to download and print for personal use.

All the components for an O'Cello can be printed on a 20cm print bed.

The O'Cello incorporates a 12mm diameter steel rod running through all six major parts to provide rigidity.

Parts list

The following parts are needed to build an O'Cello:

• M5x45mm socket head cap screws: 7
• M5x30mm socket head cap screws: 2
• M5 nuts: 9
• M5 washers: 12
• 12mm diameter steel rod, 1m length: 1
• 10mm diameter aluminium tube, 45cm length: 1
• Aluminium L-bar, 20x20x2mm, 30cm length: 1
• Cello strings: 4 – (1 of each C, G, D and A strings)
• Bass guitar tuning keys: 4 – (2 left and 2 right)
• 25mm screw plugs
• About half of a 1Kg spool of 3D printer filament. The O'Cello pictured here is made with PLA, but ABS should work fine.

Recommended sources for many of these parts can be found in the complete Assembly Instructions PDF.

The O'Cello does not need sanding or painting after printing. It is ready-to-play once printed and assembled.

Thanks to Dan Michitsch for his invaluable input on the design of the knee and chest rest parts. You can find his original design for these accessories here: http://www.thingiverse.com/thing:1833270

Check out his performance on the O'Cello here...

https://www.youtube.com/watch?v=lSVwg5sikZ4

The O'Cello is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License which means you are free to share and modify it for non-commercial use.

Update: November 23rd, 2016 - New version - This updated version now includes chest and knee rests for supporting the O'Cello while playing, and an adjustable end-pin. This is no longer a prototype, it is now ready for anyone to print and play.

Update: July 10th, 2017 - Improvement to part 6 - Some people have found it difficult to get the tuning keys to attach because the walls of part 6 were too thick. I've narrowed these walls slightly to make it easier to screw in the tuning keys.

Update: September 11th, 2020 - Original Blender file - To make remixing the O'Cello easier I'm releasing the original Blender file (updated for Blender 2.8 or later) with all the parts in their original orientations and positions. The STL files included in the download above are rotated so that they have a flat edge on the build plate, which is perfect for 3D printing but this makes them harder to modify. Download this zip file to get the parts in their original orientations and positions if you're interested in making your own remixes.

Remix Highlights

Half-inch bar and folding parts by Moe Tsao

Can't find metric measurement bars? This remix uses a half-inch bar and includes folding back and knee rests for compact storage.
https://www.thingiverse.com/thing:2759753

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Traditional scroll top by Will Newton

Try this top if you want a more traditional looking O'Cello.
https://www.thingiverse.com/thing:2672095

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Printed O' by Daddie-O

Print an O' for the front cover in any color your like using this clever remix.
https://www.thingiverse.com/thing:2427716