Dual rear lens cap for canon

I was struggling with Hooorse's design, since I wanted a single piece It also didn't thread solidly like my usual rear lens caps. I originally printed with Prusa i3 MK3; Hatchbox PLA, 20% infill. slow speed 210/55, 210/55. No brim or skirt

I was very excited to use the original, but when I printed and the cap doesn't easily screw onto the lens. Maybe if I ground it down with a file or enlarged the print to 102% it would screw on, but I can rotate the cap approx 1-2 mm before it binds. I' also