Made a new COR strainer today. Took awhile to print, but it works. I now have 2 of them running on my COR 20's
https://www.thingiverse.com/thing:3458251
From the thingiverse description:
The original strainer is great, but a complete nightmare to print with supports.
This tries to solve that, in addition, I replaced the 1" inlet, with a 1.5" BSPP thread. Now the strainer simply screws onto the pump, and you are done.
I printed mine in PETG, 100% infill. Supports
touching the build plate. If you enable normal supports, it's impossible to get extracted. Additionally, I had to turn my retractions way down, or the extruder would break my filament with all the retractions on this thing. Print it screw side down.
I also included a mod_1 version, which doesn't have the BSPP threads, and just has a ring that fits over the COR input. In case you want that.
(This is based on the wonderful model:
https://www.thingiverse.com/thing:2838063 )