telescope focusing knob

thingiverse

While crafting Fatalik's ABSDBS 8" telescope, I arrived at a critical juncture where a focuser was essential. Ultimately, I opted to create the ABSFCS-1.25 focuser, but it necessitated a knob for optimal functionality. To achieve precise focusing control, I specified a larger knob size, scaling it as far as seemed prudent. The shaft that supports it measures 6mm in diameter, thus requiring an inner hole dimension of 6.2mm; adjust accordingly to ensure a snug fit on your shaft's diameter. Additionally, my custom-made shaft features a cut-out section, prompting me to create a corresponding cutaway within the knob itself. Although this design flaw can be circumvented by drilling out the interior if necessary, the knob will still function admirably on a standard round shaft. Furthermore, I included a 3mm set screw hole in the side, although its effectiveness remains untested, as my own telescope's fit is impressively secure. Nevertheless, I am thoroughly satisfied with this design and the exceptional control it offers.