Accessibility Pen Ball - TPU two Sizes

These models are intended to be printed in TPU. 

I've added some new models and made the previous model easier to print.

They are designed to be printed with the rounded side facing up. I have had excellent results in this method and found the fuzzy skin on the outer walls to be beneficial. 

With 95a TPU I like to print these with 2 perimeters and 5% infill for a moderate amount of squish while remaining functional and comfortable. 

-Removed floating overhangs from inside friction bands

-Removed steep overhangs

-Added an alternative medium sized ball model

-Added large sized ball model

-Added Fusion360 file versions