You could use copper pipe of the diameter of your choice, and flange out one end with plumber's tools. I liked the ready-made flange on the chrome plated sink drain.
I slipped a backer plate of 3/8" thick sheet Lexan with a 2" hole over the small end of the pipe and snugged it up against the back of the flange and glued it in place. Then I cut a 1/4" sheet of Lexan into a circle the same diameter as the flange. I made a black gasket out of RTV silicone gasket making goo, from a tube. When set, I drilled 6 holes through the backer plate and the cover and tapped the backer plate holes for SS studs. I enlarged the cover plate holes slightly, and slipped the cover plate over the 6 studs, put on rubber washers, SS washers, and nuts to hold the cover plate snugly against the outside of the flange.
After installing a SubTech shaft seal in a 1/4" thick by 2" diameter circle of Lexan cut out with a hole saw, I glued the Lexan assembly into the small end of the pipe.
I can access the motor, universal joint, and shaft through the flange end cap. See picture from prior post.
I made a motor mount out of Lexan and rubber to isolate the motor from the pipe and absorb vibration.
Hope this helps.
Edited By Art Broder on 1059530219
RCABS- It's easy to control your own bladder!