Fatigue: a study of flexures in a scooter

Introducing, Fatigue, my preemptively-named flexure-based scooter.

fingers crossed for gradual, not sudden, failure

fingers crossed for gradual, not sudden, failure

You can see how a flexure is perfect for the rear brake, which has quite limited travel. Luckily, it also doesn’t see to many extreme forces. It is made from polycarbonate, about 0.1″ thick.

rear brake

rear brake

The pivot for the front fork however, needs to achieve relatively high deflection (to improve turning radius) AND it also sees lots of torsion (envision standing on the scooter deck, the deck slants to the right, and you try and stabilize by leaning the handlebars left, ouch). Needless to say, this current setup is not really optimized for high torsional stiffness. But it was pretty easy to make, and will suffice (for the near future).

The two sets of wooden bars that are screwed into the flexure were added after test riding and realizing that without some constraint, the flexure was just not stiff enough.

stress test!

stress test!

This was how I tested the idea of adding some bars to effectively shorten the flexure. There was a big hit to turning radius, but the torsional stiffness improved enough to be rideable.

lots of clamps

lots of clamps

turning radius

turning radius

bike seat clamp cam for locking the handlebars in place

bike seat clamp cam for locking the handlebars in place

it folds.

it folds.

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2 thoughts on “Fatigue: a study of flexures in a scooter

  1. Pingback: Maker Faire SF 2013 » Cesar Harada

  2. Pingback: Take Flight for Kids | Amy Qian

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