This solution could mean you never need to carry a multi-tool again

Don’t carry tools when you go for a ride. Instead, take a pocket-sized 3D printer and make whatever tool you might need, on the spot, when you have a mechanical.

This bizarre idea has been suggested by Berlin-based designer Thijs Roumen. He is determined to make bicycle mechanics easy for everybody and has made a video that shows how portable 3D printers can help cyclists in a fix.

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First he shows how a musette-sized printer can download the pattern for an allen key and fabricate a solid version.

Then he does the same again – but with a printer much more useful to a cyclist because it’s only the size of a mini-pump.

To prove it’s possible, he gets ready to tighten a light bracket on the handlebars of his bicycle.

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He squirts a fast-setting plastic from the small 3D printer into the hexagonal hole in the top of the loose bolt. It will become the business end of the allen key.

Then he downloads onto his smartphone screen the outline of a handle for the allen key and repeatedly traces over it with the hand-held printer like a pen, building up layers of plastic until they are strong enough.

Finally, the handle is fused to the hexagon of plastic in the head of the loose bolt with another blob of plastic and, hey presto!, he has a functioning 6mm allen key that fixes the problem.

Watch the mobile fabrication here

But don’t throw away your multi-tool quite yet. Roumen is going to present his concept at a technology symposium in Tokyo next week but it’s no more than a clever idea at the moment.

It’s a striking part of his mission to help people come up with their own ways to create new things. “I want to develop tools so in the future non-mechanical experts can model machines like [bicycles] and invent new, more advanced machines,” says Roumen.

Max Glaskin is an award-winning freelance journalist who tweets about cycling and science as @CyclingScience1.

He is author of Cycling Science (published by Frances Lincoln UK, Chicago University Press USA, and seven other languages).