Rokinon/Samyang 135mm f2 Ring Bracket for Astrophotography

Note: Due to differences in the shape of the Nikon vs Canon version of the lens, this file will need to be slightly modified if you wish to use this with a non-Nikon Roki/Samyang 135. Specifically, the raised lip on the inside of the rear lens ring will need to be removed in the Fusion 360 file I provided. My apologies for not knowing about this at the time. 

I have made a v2 of these rings with modules for geared autofocus (instead of a belted one in this v1), riser blocks, and a bunch of other improvements. If you're interested, you can check them out on agena's site or on my brand's website. But also literally zero worries if not – I'm leaving this v1 available for download in case you'd rather print that. 

This ring system allows you to mount a Rokinon or Samyang 135mm f2 lens to a dovetail plate for use in astrophotography. I've included both STLs and the fusion 360 files for people to edit/add on to. 

You will need:

• A handful of M6x1mm thread, 8mm long bolts. McMaster ID: 91292A201
• A handful of M6x1mm thread, 16mm long bolts. McMaster ID: 90128A263
• A handful of M6x1mm thread nuts. McMaster ID: 90591A151
• 2x M6x1mm threaded grip knobs. McMaster ID: 60765K322 
• Adhesive-backed foam strips, ~1/32" thick, ~1/4" wide. (This goes on the inside of the rings and holds your lens more gently than the raw plastic would) McMaster ID: 93375K603

If you want to include the ZWO EAF, you will also need:

• The autofocuser itself
• 1x timing belt pulley for 6mm wide belt, 5mm shaft diameter. McMaster ID: 3684N11
• 1x timing belt, 6mm wide, 350mm outer circle, 2mm pitch. McMaster ID: 7947K745
• 2x M4x0.7mm thread, 8mm long bolts (used to screw in the EAF; can use the screws that came with it, though) McMaster ID: 92137A303

To attach a guidescope, you will also need:

• A guidescope with a vixen style dovetail on it
• ZWO Vixen Style Dovetail Finder Shoe (This would be a good thing for someone to design as an upgrade to my existing design. I just didn't wanna mess with it cause $19 aint bad and it's pretty rigid). https://agenaastro.com/zwo-synta-vixen-style-dovetail-mounting-base-finder-shoe-red-zw-fs-ii.html
• 4x M4x20mm bolts. McMaster ID: 91274A121
• 4x M4 nuts. McMaster ID: 90591A141