M51 to M42 or Eyepiece Adapter

thingiverse

An adapter to convert M51x0.75mm thread to M42x0.75mm or Eyepiece holder to allow conversion of Orion/SkyWatcher 9x50 finderscope into a guidescope. Two different length adapters are included (roughly 45 and 50 mm, including threads) to allow for different focus lengths and use cases. Each has 32mm hole to allow insert eyepiece. I did not create the hole for the screw, just drill and tap to your needs. Print with 0.12 mm layer height to get good thread definition. Infill 50%, walls 3 for strength. Included FreeCad design file to allow changes in length, as this works but could be better optimized. Follow tutorial on FreeCad lesson 9 on outer thread creation, if needed.