Filament Storage Dowel End Cap v2

This improves on the original in several ways. The base is wider for more stability. The upper portion is also wider to keep the spool more centered. There is a lead in chamfer for inserting the dowel. There is also a pilot feature on the top to interface with the desiccant cages.

Oh yeah, there are also desiccant cages that stack up along the dowel for holding desiccant packets. These keep the filament stack more aligned and hold small desiccant packets, which is much neater than the la