Celestron Astromaster Low Profile Focuser

thingiverse

The stock focuser on the Celestron Astromaster 130EQ telescope falls short when it comes to attaching a DSLR camera due to inadequate back focus. Online research reveals two possible solutions: either replace the focuser with one of lower profile or move the primary mirror significantly forward - neither option yielding compatible alternatives online. Determined to design a custom focuser that reuses existing hardware, I embarked on a project to create a lower-profile focuser capable of accommodating DSLR cameras. This endeavor aimed to repurpose as much of the original equipment as possible, including the eyepiece holder, focuser knobs, metal plate securing the focuser knobs against the rack, metal coverplate, two screws holding those pieces in place on the focuser, and three screws and nuts attaching the adapter plate to the scope. Using a 3D printer at .2mm layer resolution with PLA material, I created the custom focuser in two parts held together by six M3x10 screws and six M3 nuts. Two versions of the adapter plate were designed: one featuring a border to secure the nuts and another without this feature. Initially printing the version without nut holders proved challenging as aligning the screws with the nuts was difficult. I have yet to print the other version but anticipate it will simplify the assembly process. The focuser itself includes two removable supports that must be removed for proper assembly, although they should detach easily.