RedCat 51 Rotation Collar

thingiverse

There is a built-in rotator in the RedCat 51. It's manual but uses a finely graduated ring with degree markings to set precise angles. By lining up a pointer on the rotator to the markings on the ring, accurate settings can be achieved. The problem arises when the pointer doesn't align with the camera - not even on mine. When the camera is upright, the pointer rests on the underside of the telescope. The ring with degree markings can be rotated but the zero and nearby markings remain on the underside of the scope. Moreover, the relationship between the pointer and the camera changes unpredictably depending on the adapters, filters, filter holders (or wheels), and the camera itself. It would be ideal if the pointer was adjustable and independent from the rotator to align with the camera regardless of the optical train's configuration. That's what this project aims to achieve. Two rings are designed for this purpose. The first ring is simple, featuring a notched box to hold the pointer. The pointer itself is a pointed filament that fits snugly into the notch without glue. A bit of persuasion allows the ring to fit onto the telescope rotator. Rotating the ring can be slightly stiff but it stays in position very well. I believe the second ring is unnecessary. The other ring serves multiple purposes. It helps support and hold the first ring in place. Tape or glue can make the two pieces stronger together, although they would then be fixed in position - don't apply glue while they're on the rotator. This piece also functions as a gripper to hold the RedCat's rotator while adjusting the pointer ring (if you choose not to glue them). For me, the pointer ring is doing an excellent job alone.