Introduction

The purpose of this project is to create a model for 3D printing a replacement part for the Light Hub (Atari P/N 000616-01), which is an encoder wheel for a 4 inch trackball assembly.

TODO

1. Narrowed the width of the center notch by 0.35 mm (from 1.6 mm to 1.25 mm)
   1. Need to perform next test print and see if notch is proper size to fit without filing
2. Add details on printer and settings used for test print and details on results.

Design

An official part was obtained and measured.

The following are a rough outline of the steps used to model the part in Blender 2.75a:

1. Create a cylinder.
   1. There are 36 raised pillars on outer edge of cylinder.
   2. 432 (36 * 2 * 6) vertices for cylinder, gives each raised and lowered section six faces for rounding the pillars.
2. Duplicate.
3. Shrink and boolean subtract to make outer raise ring.
4. Resize duplicate and boolean union to make inner raise ring.
5. Resize duplicate and subtract to make inner hole.
6. Make cube and union to make inner notch.
7. Select outer ring face and ctrl-f triangular faces then ctrl -f tris to quad.
8. Select six faces at a time from top of outer ring and extrude to make arms for blocking light.
9. Select vertices of raised arms to round off.

Exporting to STL

Model was designed with units left in default state. If scale is left at 1.00 when exporting to STL, this translates to each Blender unit being 1 mm and everything should print properly.