Backyard Astronomy


Focuser Positional Repeatability Test

The Feather Touch 3545 focuser on my TMB-130SS telescope has the accessory motorizing kit to move the drawtube in and out.

Accurate positional repeatability is essential when using software such as FocusMax to automatically focus the telescope. I often noticed instances of poor automated focusing, so I decided to measure the repeatability and improve it if possible. This document (PDF, 742K) describes the tests and results.

Updated September 7, 2016