Clickspring is one of the most fascinating channels on YouTube. From a 3D modeling perspective, it's always nice to see how boolean operations are applied in real life to metal to create useful tools.
Wow. Dude cuts a spiral on a tear drop--<i>freehand</i>.<p><a href="https://www.youtube.com/watch?v=3PwAQZNLy0I" rel="nofollow">https://www.youtube.com/watch?v=3PwAQZNLy0I</a>
>"The craftsmanship and ingenuity evidenced in the original led [Chris] and his collaborators to the conclusion that the calendar ring is actually a<p><i>354-day calendar that reflects a lunar cycle rather than a solar cycle</i>."