I designed this mount so that I could mount my Bird Buddy bird feeder on 1-3/8" diameter chain link fence rail. I found that it also fits 1" schedule 40 PVC pipe as well. 

I printed it out of ABS filament, 80% infill, .15mm layer height on a Voron 2.4. No supports required.

I have also included a .step file for use to modify as needed.