When I got NinjaFlex working on my 3D printer, my first goal was was to make a bouncy ball. I was disappointed when due to the 2D infill provided by my slicer, the ball was not consistent in how high or where it bounced. By using Maker Muse's method for creating even, 3D infill, I was able to engineer a better bouncy ball.

Video: https://youtu.be/JWwllOorjUw

Here is a list of the different versions you can download and how they are different:
Version 0: This was the first attempt at making a NinjaFlex bouncy ball. It is just a plain sphere and does not bounce well or consistently. It bounced anywhere from 1' 10" to 2' 8"

Version 1: This was the first attempt at using a 3D cubic lattice to improve bounciness. It was very dense and too hard. It had a wall thickness of 2mm, a tube thickness of 3mm, and a density of 7.5mm.

Version 2: This was the second try using the cubic lattice. It produced great results. It was not too dense, bounced very well, and bounced consistently. It had 4mm wall thickness, 4mm tube thickness, and 10mm density. On average, it bounces 3' 9".

Version 3: The third attempt yielded worse results than the previous one. It bounced less, (averaging 3' 4") and less consistently. It had a 3mm wall thickness, a 3mm tube thickness, and a 18mm density.