&quot;Fidget spinners&quot; are all the rage at my school; ever since they got a 3D printer the students were allowed to use, people have been printing hundreds of these little trinkets, with one skate bearing in the middle to make it spin &amp; three more as weight to increase the inertia. (The picture to the left is an example of one.) People have been &quot;battling&quot; with them like Beyblades by hitting a finger against the side and timing the spin. That&apos;s not an objective enough test for me, so I&apos;m building a machine that spins them up for a constant amount of time &amp; times how long they take to come to a complete stop.<br><br>Video:<br><a target="_blank" rel="noopener noreferrer" href="https://www.youtube.com/watch?v=CbrzxCJNXjo">https://www.youtube.com/watch?v=CbrzxCJNXjo</a><br>(Video stabilization totally messed this up)