Herringbone gear vase

I was playing with Ross Korsky's HelicalGear add-in in Fusion360, and the help text said something about Sunderland or herringbone gears. I couldn't get the add-in to create one, so I create a gear, mirrored it, then stacked the mirrored gear on top of the original. The bottoms have a hole for a ball bearing, which fit over the posts in the base. I have the vases on my desk at work, and they like to drop by and spin them a bit. They say that it's very relaxing.