Real mechanisms you say? How about a 3D printed remote control car that snaps together, uses no screws, and costs $10 in plastic?<p><a href="http:&#x2F;&#x2F;makezine.com&#x2F;projects&#x2F;3d-print-badass-rc-race-car&#x2F;" rel="nofollow">http:&#x2F;&#x2F;makezine.com&#x2F;projects&#x2F;3d-print-badass-rc-race-car&#x2F;</a>
<a href="https:&#x2F;&#x2F;github.com&#x2F;tlalexander&#x2F;Flutter-Scout" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;tlalexander&#x2F;Flutter-Scout</a><p>Note: I am the designer.